Biomass Research Projects at Celignis

The biofuel production potentials for encroacher and invasive bush biomass species found in Southern Africa were assessed using different valorization routes. Theoretical models were employed to calculate the biofuel yields. The gasification-catalytic route produced highest ethanol yields (450–488 L/t) while the lowest values were from enzymatic/acid hydrolysis-to-fermentation route. Blue gum gave the highest ethanol yields. Biodiesel and naphtha yields produced through Fischer-Tropsch synthesis were highest for blue gum (196 L/t) and lowest for Acacia raficiens (176 L/t). The highest biogas and biomethane potential of 458 L/kg.VS and 229 L/kg.VS respectively were obtained from black wattle while the respective lower values (270 L/kg.VS and 132 L/kg.VS) were recorded for blue gum. Senegalia mellifera gave the highest torrefied biofuel energy and mass yields at 0.92 and 0.97 respectively while black wattle had the lowest mass and energy yields at 0.75 and 0.83 respectively. From an energy yield basis, the acid hydrolysis-fermentation route yielded an average of 3.69 GJ/t of biomass while the highest yields came from the gasification-catalytic conversion route which was 9.7 GJ/t. The average energy yield variations across biomass species ranged 5.11–6.19 GJ/t which is around 30 % of the raw biomass' calorific value. These early results provide insights towards the best pairing of appropriate biomass species and energy conversion route. Further evaluations of these biomass-valorization technology pairing to unpack process efficiencies, cost and kinetics are required using real process experiments instead of using theoretical models. These additional tests should include sustainability assessment to guide future commercialization decisions.

Fruit juice processing generates large volumes of organic waste, including pomace, retentate, and waste apples, that are a challenge to manage. Anaerobic digestion (AD) allows for conversion of these wastes into biogas; however, their high acidity and low buffering capacity limits AD process stability, leading to reduced methane yield. In this study, co-digestion with manure and lignocellulosic biomass (LCB) was assessed. A five-factor mixture design was used to test different combinations on a bench scale, selected based-on seasonal fruit waste availability. Process performance was assessed based-on methane yield and volatile fatty acids before and after AD. Feedstock mixture representing an off-season blend of 20% pomace, 30% retentate and 50% manure, as well as an in-season blends of 20% waste apples, 30% pomace, 30% retentate, and 20% manure, were found to maximise the biomethane yield. Supplementation with at least 20% manure was essential for fruit waste digestion. Replacing a portion of the fruit waste with lignocellulose in the anaerobic digestion significantly improved the methane yield and prevented an “acid crash”. It was found that 30% LCB and 20% manure supplementation were the minimum required for anaerobic digestion process stability and yield for both in- and off-season fruit harvesting and processing.

Seaweed, an abundant third-generation biomass, has garnered significant interest for hydrocolloid extraction due to its unique composition. The extraction of these hydrocolloids, coupled with the negligible presence of lignin, leaves behind a cellulose-rich residue ideal for nanocellulose production—a potential that remains underexplored. Nanocellulose, known for its versatility, finds applications across composite, fibre, and medical industries. This review delves into the structure, composition, and extraction processes of seaweed hydrocolloids. It also investigates green emerging pretreatment techniques for hydrocolloid extraction, evaluating their advantages and limitations. This review further analyses nanocellulose produced from seaweed residues, focusing on treatment types, morphology, thermal stability, and crystallinity to determine optimal applications. Lastly, a comprehensive biorefinery approach is proposed, integrating hydrocolloid extraction and nanocellulose production to maximize the benefits from the seaweed industry.

This study presents a method for effective pectin extraction from the laminae of three tobacco varieties as a means of biomass valorisation. Two pre-treatment methods (cold ethanol vs. accelerated solvent extraction [ASE] with ethanol) were compared for their capacities to produce a high pectin yield. Enzymatic extraction of pectin was also tested as a green extraction procedure and compared to the acid extraction approach. The optimisation experiments revealed that cold ethanol extraction followed by acid hydrolysis is the most convenient method for pectin extraction; the optimal set of conditions for hydrolysis were identified as 90°C, pH 1.5, and 4 h of extraction. Applying these optimised conditions to the three Nicotiana rustica tobacco varieties yielded pectin recoveries of 66.2%, 57.8%, and 56.7% from the NRT63, Bakoum Miena, and NRT61 samples, respectively. Tobacco pectins were found to have a medium molecular weight and low methoxy content. These results highlight the potential of tobacco residues as feedstock for to produce pectin with dietary applications.

The production of high-value commodities from sugarcane bagasse and harvest residues could be integrated into existing sugarcane mills to create sugarcane biorefineries. Three distinctly different domains of operating conditions were optimised for autocatalyzed steam pretreatment and enzymatic hydrolysis of these lignocelluloses, to provide sugars according to biorefinery priorities, i.e. (i) maximum digestibility of the solids for glucose only, (ii) maximum hemicellulose recovery in the prehydrolysate for xylose only, or (iii) maximum combined sugar yield (CSY; glucose plus xylose). Bagasse pretreatment showed isolated optima for each response at (i) 215 °C, 15 min; (ii) 202.2 °C, 5 min; and (iii) 215 °C, 5 min. For the harvest residues, the three domains of optimum conditions overlapped within temperatures of 198 and 200 °C, and times of 8 and 12°min, allowing for a single pretreatment condition that meets all three criteria. The practicality and robustness of the preferred pretreatment conditions were demonstrated with a mixed stream of both feedstocks.

Brewers spent grains (BSGs) represent the largest quantity of solid waste from brewing, while xylooligosaccharides (XOS) produced from BSG show promising applications in food, beverage and health products. Production of XOS from a Weiss and malt BSG was scaled-up in steam explosion hydrothermal treatment using process conditions from bench-scale liquid hot water optimisations in stirred batch reactors. Three levels of moisture (15, 25 and 32% dry matter) achieved by screw press dewatering were evaluated by varying the treatment temperatures and times. Results show the highest XOS yields (73.1%) were obtained, for both BSGs, at process condition selected (180 C, 10 min) with 25% initial dry matter content. These yields were higher than reported bench-scale optimisations (61%), but obtained using 60% less water; hence, initial dry matter content was an important variable affecting XOS yield. The pilot-scale steam explosion results provide a departing point for a cost-effective commercial production of XOS from BSG.

Anaerobic digestion (AD) is a bioprocess technology that integrates into circular economy systems, which produce renewable energy and biofertilizer whilst reducing greenhouse gas emissions. However, improvements in biogas production efficiency are needed in dealing with lignocellulosic biomass. The state-of-the-art of AD technology is discussed, with emphasis on feedstock digestibility and operational difficulty. Solutions to these challenges including for pre-treatment and bioaugmentation are reviewed. This article proposes an innovative integrated system combining alkali pre-treatment, temperature-phased AD and bioaugmentation techniques. The integrated system as modelled has a targeted potential to achieve a biodegradability index of 90% while increasing methane production by 47% compared to conventional AD. The methane productivity may also be improved by a target reduction in retention time from 30 to 20 days. This, if realized has the potential to lower energy production cost and the levelized cost of abatement to facilitate an increased resource of sustainable commercially viable biomethane.

weet sorghum bagasse displays many characteristics rendering it a promising substrate for lignocellulosic ethanol production. In this study, the steam pretreatment catalyst, enzymatic hydrolysis and the substrate loading for the fermentation were investigated in order to maximise the production of ethanol from the feedstock. The results deemed water as a sufficient pretreatment catalyst since the SO2 impregnation of the biomass did not produce any significant beneficial effects on the yield of ethanol produced. The preferred pretreatment and enzymatic hydrolysis conditions were incorporated in a fed-batch simultaneous saccharification and fermentation (SSF) process using pressed-only (not washed) WIS at a final solid loading of 13% (w/w) that resulted in the targeted ethanol concentration of 39 g/L with a corresponding yield of 82% of the theoretical maximum. Yeast inhibition coupled with significant glucose accumulation was observed at higher solid loadings of 16% and 20%. Ultimately, the sweet sorghum bagasse could be integrated into existing ethanol production regimes to improve the global bioenergy production.

Brewers' spent grains (BSG) make up to 85% of a brewery's solid waste, and is either sent to landfill or sold as cheap animal feed supplement. Xylo-oligosaccharides (XOS) obtained from BSG are antioxidants and prebiotics that can be used in food formulations as low-calorie sweeteners and texturisers. The effect of extremely low acid (ELA) catalysis in liquid hot water (LHW) hydrothermal treatment (HTT) was assessed using BSG with dry matter contents of 15% and 25%, achieved by dewatering using a screw press. Batch experiments at low acid loadings of 5, 12.5 and 20 mg/g dry mass and temperatures of 120, 150 and 170 C significantly affected XOS yield at both levels of dry mass considered. Maximum XOS yields of 76.4% (16.6 g/l) and 65.5% (31.7 g/l) were achieved from raw BSG and screw pressed BSG respectively, both at 170 C and using 5 mg acid/g dry mass, after 15 min and 5 min, respectively. These XOS yields were obtained with BSG containing up to 63% less water and temperatures more than 20 C lower than that reported previously. The finding confirms that ELA dosing in LHW HTT allows lowering of the required temperature that can result in a reduction of degradation products, which is especially relevant under high solid conditions. This substantial XOS production intensification through higher solid loadings in HTT not only achieved high product yield, but also provided benefits such as increased product concentrations and decreased process heat requirements.

Knowing the accurate composition of biomass is of crucial importance in order to assess and decide on the use and processes to be applied to specific biomass types. In this study, the composition of the lignocellulosic constituents present in forestry, agricultural and underutilised waste residues was assessed. Considering the increased interest on hemicellulose fractions for application in biomaterials and biomolecules, large emphasis has been given in detailing the monomeric constituents of the hemicellulose polymer. Lignin and cellulose, the two other major components of lignocellulosic biomass, were analysed and correlated with the trends in the other constituents. In the samples analysed, the total structural sugars content ranged from 26.0 to 67.5% of the biomass dry weight, indicating high variation between different feedstock and fractions. Hemicellulose concentration and composition also varied significantly (from 38.8% in birch (Betula Pendula Roth) foliage to 22.0 % in rice (Oryza sativa L.) straw) between the feedstock types and within the same feedstock type between different species and different fractions. The extractives content varied greatly between the different species (from 2.66 % to 30.47 % of the biomass dry weight) with high contents in certain fractions of feedstock suggesting more detailed compositional analysis of these extracts is warranted.

Six conceptual process scenarios for the production of biobutanol from lignocellulosic biomass through acetone?butanol?ethanol (ABE) fermentation, using reported data on process performances, were developed with ASPEN Plus® V8.2 software. The six scenarios covered three fermentation strategies, i.e. batch separate hydrolysis and fermentation (SHF), continuous SHF, and batch simultaneous saccharification and fermentation (SSF) integrated with gas stripping (GS). The two downstream processing options considered were double?effect distillation (DD) and liquid?liquid extraction and distillation (LLE&D). It was found that the SSF?GS/DD scenario was the most energy efficient with a liquid fuel efficiency of 24% and an overall efficiency of 31%. This was also the scenario with the best economic outcome, with an internal rate of return (IRR) of 15% and net present value (NPV) of US$387 million. The SSF?GS/DD scenario was compared to a similar molasses process, based on the product flow rates, and it was found that the molasses process was more energy efficient with a gross energy value (GEV) of 23?MJ?kg1 butanol compared to ?117?MJ?kg1 butanol for the lignocellulosic process. In addition, the molasses?based process was more profitable with an IRR of 36% compared to 21%. However, the energy requirements for the molasses process were supplied from fossil fuels, whereas for the lignocellulose processes a portion of the feedstock was diverted to provide process energy. Improved environmental performance is therefore associated with the lignocellulosic process.

Preheating with hot air at 85-125 C was evaluated for its effectiveness in removing terpenes and terpenoids in softwood sawdust, thereby enhancing fungal preprocessing and subsequent saccharification of softwood-based mushroom substrates. Sawdust from pine (Pinus sylvestris L.) and spruce (Picea abies (L.) H. Karst.) was preheated prior to shiitake (Lentinula edodes (Berk.) Pegler) cultivation. Preheating removed up to 96?% of terpenes in pine- based substrates and up to 50?% in spruce-based substrates. Additionally, preheating decreased total terpenoids content in spruce by up to 78?%. For the pine-based substrate, the mild heating generally led to faster colonisation and improved mushroom yield, with the fastest mycelia colonisation and highest yield observed for 105 C treatment. This temperature was associated with the lowest content of total terpenes and absence of major monoterpenes. The content of terpenes and terpenoids continued to decrease during cultivation, alongside fungal degradation of lignocellulose. As a result of more extensive lignin degradation, the enzymatic digestibility of cellulose was higher for spruce-based spent mushroom substrate than for pine-based one (up to 89?% vs. 49?% conversion). Enzymatic digestibility showed a negative correlation with the a-pinene content, and a positive correlation with increasing preheating temperatures.

As a result of the current high throughput of the fast fashion collections and the concomitant decrease in product lifetime, we are facing enormous amounts of textile waste. Since textiles are often a blend of multiple fibers (predominantly cotton and polyester) and contain various different components, proper waste management and recycling are challenging. Here, we describe a high-yield process for the sequential chemical recycling of cotton and polyester from mixed waste textiles. The utilization of 43 wt% hydrochloric acid for the acid hydrolysis of polycotton (44/56 cotton/polyester, room temperature, 24 h) results in a 75% molar glucose yield from the cotton fraction, whereafter the hydrolysate solution is easily separated from the solid polyester residue. The reaction is scalable, as similar results are obtained for experiments performed at 1?mL, 0.1, and 1.0?L and even in a 230?L pilot plant reactor, where mixed postconsumer polycotton waste textile is successfully recycled. The residual polyester is successfully converted via glycolysis to bis(2-hydroxyethyl) terephthalate in 78% isolated yield (>98% purity).

The utilisation of lignocellulosic biomass for energy production has gained significant attention in recent years as a strategy to reduce carbon emissions and achieve renewable energy and net-zero targets. However, the recalcitrance of lignin in biomass hinders the effectiveness of biomethane production from anaerobic digestion, necessitating pretreatment. This study investigates the impact of a novel microbubble plasma-assisted pretreatment on structural changes in lignocellulosic biomass (maize, wheat, and rice husk) with subsequent biomethane generation. Pretreatment conditions, including durations of 1 h and 3 h under neutral, acidic (pH 3), and alkaline (pH 9) environments, were systematically investigated. Comprehensive material characterisation of untreated and pretreated material using ATR-FTIR, TGA, SEM, and XRD indicated physicochemical changes in the biomass structure, where ATR-FTIR detected lignin disruption, SEM revealed surface morphology changes, and XRD revealed minor crystallinity changes. The potential of pretreated material to generate biogas was tested using the standard BMP test. Maize pretreated in tap water for 1 h resulted in the highest biomethane yield improvement of 18% among the tested conditions. Conversely, for longer pretreatment durations of 3 h, the formation of inhibitory compounds resulted in reduced yields. Wheat and rice husk pretreated in tap water for 1 h also increased yields, but only slightly, by 5% and 7%, respectively. This study emphasises the need to optimise pretreatment duration and conditions to balance lignin breakdown and inhibitor formation and illustrates the potential of microbubble plasma-assisted pretreatment for improving Anaerobic Digestion (AD) efficiency.

The reaction mechanism and kinetics of the sulfuric acid catalysed ethanolysis of glucose, cellulose, xylan, and corncob were investigated using a combination of experiments and empirical reaction mechanism modelling. The experimental study was carried out in ethanol at various temperatures between 150 C and 200 C. Ethanol mediates the depolymerisation and formation of ethyl levulinate from the carbohydrates in the substrates. Ethanol itself is converted to the corresponding ether in a parallel acid-catalysed condensation reaction. The complementary synergistic thermal and combustion properties of the main components in the resulting mixture, ethyl levulinate, diethyl ether, and ethanol, create the potential for the use of the product mixture as a tailored drop-in biofuel. The concentrations of the main species in the product mixtures from the reaction experiments were used to build a hierarchical surrogate kinetic model based on feedstock composition. The reaction mechanism provided to the surrogate kinetic model is informed by a comparative experimental mechanistic study of the ethanolysis of glucose and fructose. The study shows that the major reaction species formed from glucose ethanolysis are ethyl glucoside and ethyl levulinate, whereas fructose ethanolysis primarily forms 5-hydroxymethylfurfural, 5-ethoxymethylfurfural, ethyl fructoside and ethyl levulinate. The study shows that fructose produces a higher yield of ethyl levulinate than glucose and that fructose does so at a rate approximately ten times faster than glucose. The rate of formation of both ethyl levulinate and diethyl ether increases with increasing temperature. The maximum yields (mass%) of ethyl levulinate achieved from the ethanolysis of glucose, cellulose, xylan, and corncob are 39.3, 39.1, 7.9, and 18.6%, respectively. Ethyl levulinate yields reach a maximum steady state value for each feedstock that is independent of temperature. The conversion of the model compounds, glucose, cellulose, and xylan, to ethyl levulinate in the presence of ethanol and sulfuric acid is a catalytic process. However, for corncob, the yield of ethyl levulinate is dependent on the concentration of sulfuric acid in the reaction. This effect is also observed in the mass fraction of diethyl ether formed, indicating that the hydrogen cation supplied by sulfuric acid is not being fully replenished in the corncob ethanolysis process. A corncob[thin space (1/6-em)]:[thin space (1/6-em)]acid mass ratio of 10[thin space (1/6-em)]:[thin space (1/6-em)]1 is identified as a sufficient sulfuric acid concentration to achieve a maximum steady state yield of ethyl levulinate. An empirical analysis of the experimental data show that the apparent activation energies of the global reaction of glucose to ethyl levulinate and ethanol to diethyl ether are 21.5 and 23.0 kcal mol-1, respectively. The hierarchical surrogate kinetic model for the ethanolysis of corncob based on its composition of cellulose, hemicellulose, and lignin was developed and has an overall R2 value of 0.88. The model was exercised to predict the major trends of the reaction system at various hypothetical conditions, demonstrating its utility as tool for process development.

Understanding the transcriptional regulation of biomass accumulation and sucrose storage is critical for enhancing sugarcane productivity. In this study, we quantified transcription factor protein (TFP) abundance across sugarcane internodes at different developmental stages and growth rates, correlating these profiles with key biochemical traits including lignin, glucan, hemicellulose, and sucrose content. Among 7333 proteins identified, 205 were classified as transcription factors spanning 22 families. Trait-centric correlation networks revealed 107 TFP-trait associations via Pearson correlation; refinement using the Partial Correlation with Information Theory (PCIT) algorithm identified 46 high-confidence regulatory links. Key transcription factors, such as ScMYB113, ScMADS15, and ScbZIP85, displayed trait-specific roles in coordinating sucrose storage and cell wall biosynthesis. Network topology uncovered distinct regulatory modules associated with biomass production, structural polysaccharide deposition, and intermediary metabolism. Notably, sucrose and lignin accumulation primarily occurred after internode elongation ceased, implicating shifts in transcriptional regulation during maturation. This study delivers the first protein-level regulatory map linking TF abundance to metabolic traits in sugarcane and provides a robust framework for identifying candidate regulators to optimize biomass quality and yield for bioenergy applications.

We report a simple procedure to produce carboxylated cellulose nanocrystals (CNCs) from grassy biomass (Miscanthus X Giganteus) using a two-step approach consisting of biomass fractionation with a protic ionic liquid followed by oxidation of the resulting cellulose-rich pulps with H2O2. The impact of the fractionation severity on the composition, structure, size, thermal stability, crystallinity, and degree of polymerization of the CNCs was evaluated. It was found that fractionation severity had a large impact on the pulp purity and its reactivity during the oxidation stage. Nevertheless, the impact on the properties of the final CNCs was small. CNCs were recovered as suspensions of negatively charged, electrostatically stable, needle-like CNCs with a lower degree of crystallinity (58-61%) compared to the precursor pulps (65-69%). The presence of carboxyl groups on the surface of the CNCs facilitated the stability of the suspensions but also caused a slight decrease in the thermal stability of the CNCs. A milder oxidation process followed by ultrasonication allowed us to maximize the production of CNCs while better preserving the degree of crystallinity of the cellulose (63%).

Sugar kelp (Saccharina latissima), a brown macroalga, is a vital crop in the burgeoning seaweed aquaculture industry. As seaweed farms expand, the traditional practice of collecting wild sporophytes will be unsustainable. Developing new kelp cultivars that suit multiple farm conditions is necessary. To address this challenge, our breeding project selected six sugar kelp crosses to be grown in New Castle, New Hampshire; Duxbury, Massachusetts; and Moriches, New York, in the 2022-2023 growing season. We measured four plot level traits (wet weight, dry weight, sporophyte density, and percent dry weight), five single blade level traits (blade length, blade maximum width, blade thickness, stipe length, and stipe diameter), and three tissue composition traits (ash content, carbon content, and nitrogen content). All plot level traits except for the percent dry weight were affected by both crosses/genotypes (G) and farm site/environments (E). All blade level traits were significantly affected by crosses. Farm effects were only detected on blade maximum width and stipe diameter. For the tissue composition traits, ash content was not affected by either cross or farm site. Carbon content was only significantly affected by the farm site, while the nitrogen content was affected by farm site, cross and their interaction effects. These findings suggest that multi-farm testing for sugar kelp breeding programs is important for determining the best crosses for various growers. Understanding G by E effects can advance sugar kelp breeding for targeted traits and farms that will facilitate the adoption of cultivars toward sustainable economic growth on diverse kelp farms.

Economic production of fermentable sugars from lignocellulosic biomass is critical for the biorefinery applications in the bioeconomy industry. This study demonstrates effective enzymatic hydrolysis of recalcitrant softwood using newly identified fungus Penicillium rotoruae. Initially, nineteen fungal isolates were screened on softwood galactoglucomannan (GGM), with nine showing strong responses in the liquid culture. Trichoderma viride, Penicillium rotoruae, and Amorphotheca resinae showed highest B-mannanase, B-mannosidase, and a-galactosidase activities. P. rotoruae demonstrated superior main chain cleaving enzyme activities, while A. resinae excelled in the side chain cleaving activity. The crude enzyme of P. rotoruae was evaluated on two Pinus radiata substrates. Using soluble GGM, P. rotoruae released 34.3% monomeric sugars (32.1 g/L reducing sugars), outperforming commercial CTec-2 (22.9% and 23.2 g/L respectively). Co-application of CTec-2 with P. rotoruae enzymes increased monomeric sugar yield to 56.3%, with galactose, mannose, and glucose increasing 20-, 3.6-, and 2.2-fold respectively. Using insoluble pulp, co-application yielded 88% of monomeric sugars (20.2 g/L reducing sugars) representing an increase of 20% soluble sugars relative to CTec-2 used alone. Techno-economic analysis indicated an increase in annual EBITDA, a positive ROCE and sugar cost savings of NZD 125/t demonstrating significant economic potential for softwood biorefineries.

A number of biomass processing plants that use torrefaction technology are coming up globally as this technology advances from several years of pilot and laboratory research studies to commercialization. However, continued and sustainable growth of biomass torrefaction industry hinges on the accessibility to critical technology information by decision makers especially on process efficiency measurement. This study attempts to organize and put together critical process efficiency measurement information about torrefaction technologies and later zeroes on one specific torrefaction technology called the superheated steam (SHS) torrefaction technology. The study focusses on different torrefaction technologies' applicability to processing bush encroacher and invasive bush species commonly found in Southern Africa. The study includes (a) a brief and general review of torrefaction processing plant performance metrics (b) a collection of plant and product performance information pertaining to a case study that employed SHS torrefaction technology on encroacher and invasive bush species of Southern Africa. The main objective of this study is to disseminate knowledge that can be useful in advancing SHS torrefaction technology towards addressing bush encroachment related issues, while fighting climate change through the production of renewable solid biofuels and biochemicals from these bushy woods. The review established that SHS torrefaction of Southern African encroacher and invasive bushes is technically feasible although additional optimization studies are required to prove commercial viability and improve competitiveness of the technology over fossil based processes and products.

In this work we aimed to increase the food potential of UK pasture by coupling targeted mechanochemical processing and novel biotechnology to convert silage into edible protein and lipid fractions. To this end, the water-soluble protein and vitamins were extracted from silage using a twin-screw extruder at room temperature. The extrusion of the silage was optimized in water with no additional chemicals. Under optimal conditions, 22 wt% of the silage was solubilized, with this fraction containing 52% of the protein present from the original material. The protein contained key essential amino acids with a profile similar to soy protein. Vitamins B1, B2, B3 (nicotinamide and nicotinic acid) and B6 (pyridoxine, pyridoxal and pyridoxamine) were also extracted. The resulting solids from the extruder, which contained further insoluble protein and the carbohydrates from the silage, were then depolymerized and used to culture the oleaginous yeast Metschnikowia pulcherrima producing further mycoprotein and lipid from the system. The mycoprotein contained a balanced amount of vital amino acids, while the yeast lipid had a fatty acid profile containing high levels of monounsaturated lipids. The silage was also found to contain high value lipids, rich in omega-6 linolenic acid. The work presented here represents a preliminary study but highlights the possibility of extracting edible nutrients from grass feasibly, with the potential to make UK agriculture far more resilient and sustainable.

Sugarcane is a globally important C4 crop traditionally bred for sucrose yield. However, its potential as a bioenergy crop depends on understanding lignocellulosic quality across developmental stages and environments. This study investigates the variability in fibre composition and theoretical digestibility among 17 sugarcane genotypes grown at two contrasting locations in northern Queensland. Plants were sampled at maximum vegetative growth and at peak sucrose accumulation. Fibre traits, including glucan, xylan, and lignin content, were quantified, and digestibility was estimated using cell wall composition ratios. The results revealed that digestibility declined with plant age, primarily due to increased lignin and xylan deposition. However, several genotypes maintained relatively high digestibility even at later stages. The study also identified substantial genotype-environment interactions influencing biomass quality. These findings suggest that harvesting sugarcane earlier in the cropping cycle, particularly when sucrose is not the main product, could improve fibre digestibility and biomass yield per unit time. This supports the use of sugarcane in circular bioeconomy systems and highlights opportunities for developing dual-purpose cropping strategies that align with sustainability goals.

This investigation explores the enhancement of CH4 generation in anaerobic digesters (AD) via in-situ renewable hydrogen injection utilising four exotic crop wastes and a crop (five feedstocks). The substrates are yam, cassava, and cocoyam peel (YP, CP and CYP), rice husk (RH) and finger millet seeds (FMS). Biomethane Potential (BMP) Tests, followed by AD experiments with food waste inoculum (FWI), were conducted in triplicate under mesophilic conditions (37 C), utilising an anaerobic model (ANM) test rig. The last phase of the experimental campaign is bio-methanation to upgrade CH4 purity. CYP and YP showed 233% and 81.5% higher gas yields, respectively, with CH4 content improvements up to 38.5%. However, CP emerged as the optimal feedstock, hence the primary substrate utilised in the AD, supporting hydrogenotrophic methanogenesis (HM) and CO2 to CH4 conversion. Consequently, MATLAB-based kinetic modelling confirmed the Richard equation as the best fit predictor. The novelty of this study lies in the innovative incorporation of in-situ H2 injection (0.67 ml/min), bubble mixing and mass transfer to enhance CH4 from tropical crop waste (cassava peel), a widely available yet underutilised feedstock specific to Plateau State, Nigeria. Additionally, integrating computational fluid dynamics (CFD) and bioprocess kinetic modelling provides a comprehensive framework for understanding the parameterisation and optimising system dynamics. This consolidates the research contribution to the experimental optimisation of decentralised biogas systems, facilitating sustainable energy solutions for pipeline quality in tropical regions.

Biobased materials are developed and utilized to reduce dependence on petroleum-based resources, protect the environment and reduce carbon emissions. Meanwhile, chemical recycling of thermosetting materials is an emerging strategy to increase the added value of post-consumer waste. Nevertheless, most thermosets have proved difficult to recycle due to the high stability of their crosslinked structure. Vitrimers, crosslinked by dynamic chemical bonds, are the perfect solution to recycling problems. Here, we report lignin-based vitrimers prepared by imine chemistry. First, aldehyde-modified lignin was successfully prepared by treating OH functionalized lignin with a dialdehyde via an acetalization reaction. The modified lignin acts as both a hard segment and crosslinker and the soft segment is a fatty acid diamine (Priamine (TM) 1075), which is chemically crosslinked via imine chemistry. The mechanical properties of lignin-based vitrimers (LPs) with more than 81.4% biobased content can be adjusted by blending the ratio of hard to soft segments. The resulting imine bond in LPs is highly dynamic at elevated temperatures (LP-40%, Ea = 49.6 kJ mol-1) allowing the material to be thermally recycled three cycles via imine metathesis and transimination without any catalyst. Unique hydrolytic properties of the imine bond endow the material with chemical recycling properties under acidic conditions (LP-40%, 62.0% tensile stress recovered). A potential application for this work is a coating, which can be prepared by hot pressing. In addition to the excellent coating properties, the LP coatings also possess thermal repairable, self-cleaning, removable, and degradable properties, which are not available with conventional coatings.The successful integration of biomass material (lignin) and the concept of dynamic imine bonds has led to the development of lignin-based vitrimers. These materials hold promise for applications in repairable and UV-shielding coatings.

Hydrothermal carbonization (HTC) research has mainly focused on primary char production, with limited attention to secondary char, which is formed through polymerization and condensation of dissolved organic compounds in the liquid phase. This research aims to address this gap via an experimental investigation of the impact of stirring on the mass and carbon balance of HTC reaction products, surface functional groups, and surface morphology of secondary char, using fructose as a model compound. A 3D hydrodynamic simulation model was developed for a two-liter HTC stirred reactor. The experimental results indicated that stirring did not significantly influence the pH, mass, carbon balance, and surface functional groups of secondary char produced under the range of experimental conditions (180 C, 10% biomass to water (B/W) ratio, and a residence time of 0-120 min) studied. Nonetheless, it was observed that a stirring rate of 200 rpm influenced the morphology and shape of the secondary char microspheres, leading to a significant increase in their size i.e., from 1-2 um in unstirred conditions compared with 70 um at a stirring rate of 200 rpm. This increase in size was attributed to the aggregation of microspheres into irregular aggregates at stirring rates > 65 rpm and residence times > 1 h. The hydrodynamic model revealed that high turbulence of Re > 104 and velocities > 0.17 m s-1 correlated with regions of secondary char formation, emphasizing their role in particle aggregation. Particle aggregation is significant above a stirring rate of 65 rpm, which corresponds to the onset of turbulent flow in the reactor. Finally, a mechanism is proposed, based on reactor hydrodynamics under stirred conditions, that explains secondary char deposition on the reactor walls and stirrer.

Lignocellulosic residues (LRs) are one of the most abundant wastes produced worldwide. Nevertheless, unlocking the full energy potential from LRs for biofuel production is limited by their complex structure. This study investigated the effect of N-methylmorpholine N-oxide (NMMO) pretreatment on almond shell (AS), spent coffee grounds (SCG), and hazelnut skin (HS) to improve their bioconversion to methane. The pretreatment was performed using a 73% NMMO solution heated at 120 C for 1, 3, and 5 h. The baseline methane productions achieved from raw AS, SCG, and HS were 54.7 (+/- 5.3), 337.4 (+/- 16.5), and 265.4 (+/- 10.4) mL CH4/g VS, respectively. The NMMO pretreatment enhanced the methane potential of AS up to 58%, although no changes in chemical composition and external surface were observed after pretreatment. Opposite to this, pretreated SCG showed increased porosity (up to 63%) and a higher sugar percentage (up to 27%) after pretreatment despite failing to increase methane production. All pretreatment conditions were effective on HS, achieving the highest methane production of 400.4 (+/- 9.5) mL CH4/g VS after 5 h pretreatment. The enhanced methane production was due to the increased sugar percentage (up to 112%), lignin removal (up to 29%), and loss of inhibitory compounds during the pretreatment. An energy assessment revealed that the NMMO pretreatment is an attractive technology to be implemented on an industrial scale for energy recovery from HS residues.

Grass, a low-cost lignocellulosic feedstock with relatively low lignin content, serves as a potential carbon source for microbial processes due to its polymeric sugar content. However, converting carbohydrates into monomeric sugars presents challenges due to complex lignocellulosic matrix. In this study, a mixture of perennial ryegrass and white clover (RG) was pretreated with alkaline before being enzymatically hydrolysed for use as a fermentable sugar source for the oleaginous yeast Metschnikowia pulcherrima. The dilute alkaline pretreatment approach resulted in a 3 times improvement in the conversion of RG, yielding a fermentable sugar concentration of 56.5 g/L. The yeast exhibited a growth yield (Ym/m) of 0.47, producing 23.7 g/L of dry cell weight at 20 C over 140 hours, with a lipid content of 37 % with a similar composition to high oleic palm oil. These findings suggest that RG can be utilised for formulating an oleaginous yeast medium containing the necessary nutrients.

This study proposes a chemical recycling pathway for valorizing the cellulosic component of municipal waste streams such as textile, cleaning wipes, corrugated cardboard, contaminated cardboard (i.e. a pizza box), paper-plastic laminate (PPL) coffee cups and cigarette butts (CBs). The goal of this study is to establish an experimental procedure that allows to test a broad range of cellulose-containing waste materials, laying the groundwork for commercial deployment of their chemical recycling. The cellulose contained in these materials is transformed into 5-chloromethylfurfural (CMF), a precursor for bio-based plastics, without affecting the plastic counterpart (if present). We employ a biphasic system concept using aqueous HCl solutions for CMF formation and in situ extraction from the reaction medium using immiscible organic solvents, enabling straightforward product separation. This method allows to hydrolyze cellulosic materials from waste without affecting PET or polyolefin plastic also present, facilitating the subsequent recycling of this plastic as well. This study serves as a foundation to assess the feasibility of using cellulose-containing waste streams for chemical recycling and to offer recommendations on selecting optimal reaction procedures.

Brewer's spent grain (BSG) contains a large fraction of proteins, lignin, and carbohydrates. However, its heterogeneous composition limits its use in the food industry. The current work evaluated a cascade process for fractionation of these compounds. Two different thermally diluted acid pretreatments prior to enzymatic hydrolysis steps were evaluated. Condition 1 (C1) corresponded to 0.49% (v/v) HCl at 87.7 C for 92.7 min, and C2 used 0.80% HCl at 121.0 C for 142 min. Three different solid fractions were obtained for each condition, a fine solid (FS) (particle size <25?m), a coarse solid (CS) rich in protein and fiber, and an alkaline solid (AS) rich in fiber. The fractions had water retention capacities between 4.0 and 8.8 gH2O/gTS. The highest protein content was obtained for C1-FS (31.5% w/w), and the highest total fiber content for C2-AS (>80%). Some of those fractions have characteristics similar to those of current market ingredients used in the food industry.

Haemorrhage control during surgery and following traumatic injury remains a critical, life-saving challenge. Cellulose products are already employed in commercially available haemostatic dressings. This work explores sourcing cellulose from sugarcane trash pulp to produce micro- and nanosized fibres with hydroxyl, carboxylic acid, and trimethylamine functional groups, resulting in either positive or negative surface charges. This paper assesses the influence of these fibres on multiple blood clotting parameters in both dispersed solutions and dry gauze applications. In vitro blood clotting studies demonstrated the significant haemostatic potential of cellulose fibres derived from sugarcane waste to initiate clotting. Plasma absorbance assays showed that the 0.25 mg/mL cellulose microfibre dispersion had the highest clotting performance. It was observed that no single property of surface charge, functionality, or fibre morphology exclusively controlled the clotting initiation measured. Instead, a combination of these factors affected clot formation, with negatively charged cellulose microfibres comprising hydroxyl surface groups providing the most promising result, accelerating the coagulation cascade mechanism by 67% compared to the endogenous activity. This difference in clot initiation shows the potential for the non-wood agricultural waste source of cellulose in haemostatic wound healing applications, contributing to the broader understanding of cellulose-based materials' versatility and their applications in biomedicine.

Monosaccharides such as L-arabinose (Ara) and D-tagatose (derived from D-galactose, Gal) are low-calorie sweeteners associated with improved glycaemic and insulin control compared to disaccharides such as sucrose. However, alternative sources and better sugar-sugar separation methods are needed to improve the sustainability and economics of their production. Here, these sugars were obtained from purified and ultrafiltered compression screw pressate (CSP) of thermo-mechanical pulping of softwood (Pinus radiata) and orange peels (OPs). Ba- substituted zeolite X (BaX) molecular sieves showed superior separation performance of Ara from other sugars compared to conventional Ca-form ion exchange resin. To facilitate subsequent separation of sugars, OP hydrolysates were fermented to leave just Ara and Gal, while OP pectin was hydrolysed to generate a Gal-rich mixture. Overall, BaX has good potential for separating Ara from Ara-rich hydrolysates containing several different sugars. It is also suited for separating Ara and another monosaccharide such as Gal or Xyl in the absence of other sugars.

Value added lignin rich waste sludges from biorefinery processes are, as yet untapped valuable feedstocks that can be reformed into clean, high quality solid fuels. By water washing sludges produced from base hydrolyzed waste, a material stripped of water-soluble alkali and alkaline earth metals (ash) can be obtained. This work shows how leached bagasse, barley and wheat straw sludges can be valorised into clean, low ash solid biofuels that can be used to supplement global energy demands. Repurposed lignin rich sludges of 1.00-2.00mm particle size feedstocks were found to exhibit calorific values +17.3%, +16.8% and +11.7% for bagasse, wheat, and barley straw sludges, respectively higher than their untreated waste counterparts. Additionally, by employing densification in the absence of a binder, <0.25mm particles of leached sludge feedstocks were found to experience 16.0% (bagasse), 12.0% (wheat) and 4.0% (barley) increases to their calorific values. This provides options for sustained energy from waste production and consumption campaigns, diversifying feedstock options for green solid fuels

Radiocarbon (D14C) measurements of nonstructural carbon enable inference on the age and turnover time of stored photosynthate (e.g., sugars, starch), of which the largest pool in trees resides in the main bole. Because of potential issues with extraction-based methods, we introduce an incubation method to capture the D14C of nonstructural carbon via respired CO2. In this study, we compared the D14C obtained from these incubations with D14C from a well-established extraction method, using increment cores from a mature trembling aspen (Populus tremuloides Michx). To understand any potential D14C disagreement, the yields from both methods were also benchmarked against the phenol-sulfuric acid concentration assay. We found incubations captured less than 100% of measured sugar and starch carbon, with recovery ranging from ~3% in heartwood to 85% in shallow sapwood. However, extractions universally over-yielded (mean 273 +/- 101% expected sugar carbon; as high as 480%), where sugars represented less than half of extracted soluble carbon, indicating very poor specificity. Although the separation of soluble and insoluble nonstructural carbon is ostensibly a strength of extraction-based methods, there was also evidence of poor separation of these two fractions in extractions. The D14C of respired CO2 and D14C from extractions were similar in the sapwood, whereas extractions resulted in comparatively higher D14C (older carbon) in heartwood and bark. Because yield and D14C discrepancies were largest in old tissues, incubations may better capture the D14C of nonstructural carbon that is actually metabolically available. That is, we suggest extractions include metabolically irrelevant carbon from dead tissues or cells, as well as carbon that is neither sugar nor starch. In contrast, nonstructural carbon captured by extractions must be respired to be measured. We thus suggest incubations of live tissues are a potentially viable, inexpensive and versatile method to study the D14C of metabolically relevant (available) nonstructural carbon.

This study explores the hydroxycinnamic acid extraction from prairie biomass as a potential value-added pretreatment for enhancing the performance of anaerobic digestion. Pretreatment increased the biomethane potential of prairie biomass by 33 %; when the extraction residue was left on the biomass, the biomethane potential increased by 100 %. When the treated biomass was co-digested with manure, a 134 % and 25 % increase in methane productivity and methane content was obtained, respectively, relative to raw biomass co-digested with manure. Hydroxycinnamic acid extraction also improved anaerobic digestion performance under biochar supplementation and liquid digestate recirculation conditions. Lastly, the extraction process was optimized for hydroxycinnamic acid yield. It was found that increases in treatment temperature and time could further increase yield by 5 %. Collectively, the results show hydroxycinnamic acid extraction can be used as a highly effective pretreatment for improving the anaerobic digestion of prairie biomass.

Although industrial hydrothermal carbonization (HTC) uses wet feedstock, lab-scale studies tend to dry the feedstock under the assumption that the rehydration of the feedstock would restore its original properties. To the best of our knowledge, this assumption has not been thoroughly examined at the lab scale; therefore, its investigation is crucial to prevent any discrepancies that might affect the upscaling of HTC. This research aims to examine the effects of pre-drying biomass by comparing it to the use of wet biomass in HTC experiments, employing three different types of biomass (rejected tomatoes, rejected apples, and digestate). Additionally, the study investigates the influence of stirring on pre-dried and wet biomass under the selected HTC conditions. The results indicate a substantial disparity in studied hydrochar properties when using pre-dried biomass compared to wet biomass. For pre-dried biomass, there is a tendency for an increase in mass yield and solid carbon yield in most examined samples (5-10% dry basis) compared to the wet biomass. Regarding functional groups, wet tomatoes and apples exhibit more pronounced peaks than pre-dried samples. Conversely, digestate shows similar spectra across all examined scenarios. The effect of stirring appears insignificant for most of the studied scenarios; nevertheless, it reduced dehydration and decarboxylation reactions during HTC.

A dried dairy processing sludge (sludge from wastewater treatment of an effluent from a milk processing plant) was pyrolysed in a single-particle reactor at different temperatures from 400 C to 900 C. NH3 and HCN were measured online and offline by means of FTIR as well as by cumulative sampling in impinger bottles (in 0.05 M H2SO4 and 1 M NaOH, respectively) and analysed by photometric method. NO and NO2 were measured online using a nitric oxide analyser while N2O was measured by FTIR. Nitrogen (N) in the sludge and in the remaining char, char-N, was determined. Moreover, tar content in pyrolysis gas was measured and tar-N was determined. The results with respect to N mass balance closure are discussed. The different measurements techniques are compared. For pyrolysis at 520 and 700 nitrogen in the gas phase was mainly contained as N2 (36 % and 40 % respectively), followed by NH3 (15 % and 18 %), tar-N (10 % and 9 %), HCN (1 % and 3 %), NO (1 %) and NO2 (0.2 %). The dairy processing sludge has very specific properties with organic-N present predominantly as proteins and a high content of inherent Ca. These characteristics affected the distribution of N. The amount of char-N was higher while the amount of tar-N lower than for sewage sludge from literature, at comparable pyrolysis temperature.

The relationship between metabolic changes occurring in the developing internodes of sugarcane and the final yield and sugar characteristics is poorly understood due to the lack of integration between phenotypic and metabolic data. To address this issue, a study was conducted where sugarcane metabolism was modeled based on the measurement of cellular components in the top internodes, at two stages of crop development. The study also looked at the effects of Trinexapac-ethyl (Moddus) on growth inhibition. The metabolome was measured using GC-analysis, while LC-MS/MS was used to measure proteome changes in the developing internodes. These data were then integrated with the metabolic rates. Regardless of the growth rate, internode elongation was restricted to the top five internodes. In contrast, sucrose and lignin accumulation was sensitive to the growth rate. Crossover plots showed that sucrose accumulation only occurred once the cell wall synthesis had slowed down. These data suggest that sucrose accumulation controlled a reduction in sucrose breakdown for metabolic activity and a reduction in demand for carbon for cell wall polysaccharide synthesis. This study also found that nucleotide sugar metabolism appears to be a key regulator in regulating carbon flow during internode development.

Considering the current transition to biobased carbon sources and the search for viable extraction procedures, the microwave-assisted solubilization of seaweed biomass was explored. Hereto, the brown North Sea native species Ascophyllum nodosum was processed using water as green extraction solvent. Response surface methodology was used to determine the best solubilization conditions towards maximizing the solubilization efficiency and minimizing the applied energy per mass of solubilized seaweed by varying (i) temperature, (ii) time and (iii) solid to liquid ratio (S/L). It was found that a temperature of 120 C, a processing time of 15?min and a 1.03 w:v S/L are most suitable to achieve the pre-set criteria. Concurrently, mass balances were developed with respect to total lipid, polysaccharide, protein, mineral and heavy metal contents. Moreover, zeta potential measurements were performed to link the obtained values and the antimicrobial characteristics of the extracts. Finally, antimicrobial tests on S. aureus and E. coli were conducted and with results indicating up to 97?% inhibition of bacterial growth after 8?h, antimicrobial characteristics were indeed observed.

The importance of reducing the strong dependence of the chemical industry on fossil feedstock is no longer a debate. Above-the-ground carbon is abundant, but scalable technologies to supply alternatives to fossil-fuel-derived chemicals and/or materials at the world scale are still not available. Lignocellulosic biomass is the most available carbon source, and a first requirement for its valorization is the complete saccharification of its sugar-bearing components. HCl-based technologies can achieve this at 20 C and ambient pressure. These principles were disclosed in the 1920s, but the inability to economically separate sugars from acids impeded its commercialization. Avantium Chemicals B.V. developed a modern version of this 'Bergius' highly concentrated acid hydrolysis, in which the saccharides in HCl are transformed into furanics without any prior purification, in particular, to 5-(chloromethyl)furfural (CMF). Saccharide conversion to CMF was developed by Mascal in the early 2000s. CMF is extracted in situ using immiscible organic solvents, allowing for an easy product separation. This study not only targets to investigate the viability and optimization of this integrated process but also aims to predict the outcome of the CMF formation reaction by applying design of experiment techniques from the hydrolyzed saccharides varying a broad range of reaction parameters.

The Organic Fraction of Municipal Solid Waste (OFMSW) contains paper and cardboard, an attractive cellulosic feedstock for bioethanol production. Waste paper/cardboard (WPC) was subjected to mild acid treatment in solids loadings from 20 to 27.5 %. Different doses of commercial enzyme cocktail and various adjuvants facilitating enzymatic saccharification were tested. Enzyme dosing of 3.75 FPU/g fiber with very slow fed-batch saccharification of 27.5 % (w/v) solids from model lignin-free paper pulp resulted in 12.6 % (w/v) total sugar after 74 h. Use of cheap non-catalytic waste protein adjuvants including Soymeal, Protisyr, Feather meal strongly improved enzymatic saccharification and reduced the overall process cost by reducing commercial enzyme dosing. After fermentation with the industrial yeast strain BMD44 (Cellusec 1.0) an ethanol titer of 5.77 % (v/v) was obtained using a reduced enzyme loading of 2.5 FPU/g of actual industrial WPC fiber. These results show the potential of economically profitable second-generation bioethanol production with WPC fiber.

This study tested the hypothesis that post-harvest hot water blanching improves the chemical composition, mainly mineral and carbohydrate contents, and in vitro digestibility of two predominant brown macroalgae, Ascophyllum nodosum (AN) and Fucus vesiculosus (FV), as feed ingredients for monogastric and ruminant animals. Low-temperature water blanching (LTB; 40 C for 5 min) had minor impacts on macroalgal chemical composition and in vitro digestibility. Conversely, high-temperature water blanching (HTB; 80 C for 5 min) effectively reduced total ash and specific elements, including sodium, potassium, iodine, and arsenic, by ~ 25–73% compared to unblanched algal biomass (more prominently in FV). The HTB raised total sugar contents by ~ 25% in FV, markedly elevating uronic acids (~60%) and glucans (~33%). However, HTB reduced mannitol (>50%) and enhanced total polyphenol extractability in both macroalgae. The HTB diminished ~ 8% of in vitro dry matter or organic matter digestibility and 26% of crude protein (CP) digestibility of both macroalgae for monogastric animals and of FV for ruminants (particularly of CP by ~ 42%). Those reduced digestibilities were associated with enriched fibre, uronic acids, total polyphenols, and declined mannitol in the HT-blanched macroalgal biomass. Our findings suggest that hot-water blanching can be an efficient technique to optimise the elemental composition of two fucoid algae, but the altered sugar and complex carbohydrate compositions may impair their digestibility. Future studies should identify appropriate post-harvest processing techniques for brown macroalgae that can optimise both nutritional composition and digestibility along with favourable impacts on feed utilisation and animal performance.

Lignocellulosic biomass plays a vital role in the global shift away from the utilisation of non-renewable petrochemical resources. An emerging class of biomass-derived material is nanocellulose, which are typically generated from the deconstruction of cellulose bundles within the cell wall of terrestrial and aquatic plants, either in the form of cellulose nanocrystals (CNCs) or cellulose nanofibres (CNFs). However, the utilisation of biomass has an inherent challenge associated with product variability, both in terms of the starting feedstock properties, the wide range of processing routes available to generate nanocellulose, and the fabrication of nanocellulose into a diverse range of different product formats. As a result, it is difficult to accurately characterise and benchmark the wide variety of nanocellulose materials described within the literature. To address this challenge, this study presents a threefold benchmarking assessment of CNF-based material, including: (1) CNFs generated from different biomass sources (sorghum, banana, sugarcane, spinifex, and softwood); (2) CNFs generated through different mechanical processing methods (Silverson mixing, twin-screw extrusion, bead milling, and high pressure homogenisation); and (3) Energy-standardised nanopaper mechanical performance presented within applicable literature studies. The biomass benchmarking study highlighted sorghum and banana stem as comparatively sustainable biomass feedstock, while the mechanical process benchmarking study highlighted twin-screw extrusion as a promising fibrillation method with relatively low energy consumption. Lastly, the nanopaper benchmarking study aided in the visualisation of the nanopaper research landscape. Overall, sample benchmarking in this manner provides greater insight into the mechanisms driving nanocellulose material performance and processing sustainability.

Biochar is an engineered carbon-rich substance used for soil improvement, environmental management, and other diverse applications. To date, the understanding of how biomass affects biochar microstructure has been limited due to the complexity of analysis involved in tracing the changes in the physical structure of biomass as it undergoes thermochemical conversion. In this study, we used synchrotron x-ray micro-tomography to visualize changes in the internal structure of biochar from diverse feedstock (miscanthus straw pellets, wheat straw pellets, oilseed rape straw pellets, and rice husk) during pyrolysis by collecting a sequence of 3D scans at 50 C intervals during progressive heating from 50 C to 800 C. The results show a strong dependence of biochar porosity on feedstock as well as pyrolysis temperature, with observed porosity in the range of 7.41-60.56%. Our results show that the porosity, total surface area, pore volume, and equivalent diameter of the largest pore increases with increasing pyrolysis temperature up to about 550 C. The most dramatic development of pore structure occurred in the temperature range of 350-450 C. This understanding is pivotal for optimizing biochar's properties for specific applications in soil improvement, environmental management, and beyond. By elucidating the nuanced variations in biochar's physical characteristics across different production temperatures and feedstocks, this research advances the practical application of biochar, offering significant benefits in agricultural, environmental, and engineering contexts.

Dairy processing sludge (DPS) is a byproduct generated in wastewater treatment plants located in dairy (milk) processing companies (waste activated sludge). DPS presents challenges in terms of its management (as biosolids) due to its high moisture content, prolonged storage required, uncontrolled nutrient loss and accumulation of certain substances in soil in the proximity of dairy companies. This study investigates the potential of hydrothermal carbonization (HTC) for recovery of nutrients in the form of solid hydrochar (biochar) produced from DPS originating from four different dairy processing companies. The HTC tests were carried out at 160 C, 180 C, 200 C and 220 C, and a residence time of 1h. The elemental properties of hydrochars (biochars), the content of primary and secondary nutrients, as well as contaminants were examined. The transformation of phosphorus in DPS during HTC was investigated. The fraction of plant available phosphorus was determined. The properties of hydrochar (biochar) were compared against the European Union Fertilizing Products Regulation. The findings of this study demonstrate that the content of nutrient in hydrochars (biochars) meet the requirements for organo-mineral fertilizer with nitrogen and phosphorus as the declared nutrients (13.9-26.7%). Further research on plant growth and field tests are needed to fully assess the agronomic potential of HTC hydrochar (biochar).

A novel thermo-mechanical pulping (TMP) process has been developed to produce a by-product rich in high-molecular weight (MW) hemicelluloses, a potential raw material for barrier coatings and films. This process uses prehydrolysis to solubilise the hemicelluloses followed by chip compression to separate the soluble material from the wood matrix. The pressate from the chip compression stage was dark-coloured and had a high content of high-MW hemicelluloses and lignin. However, isolating the high-MW material from the pressate directly by ultrafiltration was not feasible because of membrane fouling by dissolved lignin and wood extractives, while coloured impurities are undesirable for many potential applications. To solve these problems the pressate was purified using XAD adsorbent resin to remove low-MW lignin, extractives and colour. Ultrafiltration of the purified pressate yielded lightly coloured high-MW hemicellulose with a low content of lignin and well suited for barrier films and coatings.

Disposal of waste-activated sludge [dairy processing sludge, (DPS)] from wastewater treatment plants located in milk processing companies is an increasing concern. DPS is usually applied to farmlands in the vicinity of the dairy companies. This practice is becoming unsustainable due to uncontrolled nutrient loss and potential soil contamination. We propose to recover nutrients in the form of biochar. This paper examines the properties of biochars obtained from slow pyrolysis of DPS. DPS samples were pyrolyzed at laboratory and pilot scale at 600 and 700 C. The elemental properties of biochars, the content of primary and secondary nutrients, as well as contaminants were examined and compared against the European Union Fertilizing Products Regulation. The biochars meet the specified limits for hydrogen-to-organic carbon ratio, chloride, and polycyclic aromatic hydrocarbons intended for gasification and pyrolysis component category materials. In six out of eight biochars, the content of phosphorus (P) as a single declared nutrient and the level of contaminants meet those required for an organo-mineral fertilizer. Only two biochars meet the required concentrations of nitrogen, phosphorus, and potassium. A minimum solid content of 30% in DPS is required to make the process of biochar production energetically sustainable.

Polymer materials today face significant challenges, notably the utilization of green and low-carbon feedstock, the development of eco-friendly preparation processes, and effective material recycling. A promising solution to these challenges lies in the direct synthesis of covalent adaptable networks (CANs) from biomass sources, like lignin. However, the development of unmodified lignin CANs via catalyst-free methods has been a challenging task. Here, we report the successful preparation of lignin-based CANs (TERs) via phthalate monoester transesterification. In this system, lignin (PB1000) serves as hard segment and crosslinker, while the soft segment consists of a biomass diol (PripolTM 2033). By blending the ratio of hard to soft segments, we were able to tune the mechanical properties of the TERs (with lignin content ranging from 10 to 50 wt% and crosslink density increasing from 3600 mol/m3 to 47900 mol/m3). Monoester bonds within the TERs are highly dynamic at elevated temperatures (with an activation energy of 169.2 kJ mol-1), facilitating material recycling without the need for catalysts. Furthermore, TERs can be chemically recycled via alkaline solutions at 80 C. Notably, we demonstrate a potential application for this work in the form of a TER-based adhesive. In addition to its excellent adhesion properties, the TER adhesive exhibits thermal repair ability, removability, and degradability properties. This work provides a green and sustainable approach towards tackling the challenges associated with recycling of thermoset plastics.

Development of low-cost anode for sodium-ion battery (NIB) has become the most desirable target in today's energy demanding society. In this work, we present different treatments of sugarcane biomass to alter the lignocellulose compositions to obtain low-cost porous carbon as NIB's anode. The optimized sugarcane biomass derived carbon presents the initial reversible capacity of 229 mAh g-1 and the reversible capacity of 189 mAh g-1 at 100 mA g-1 after 50 cycles. It is worth noting that the carbon also exhibits an extremely low voltage plateau with 74.2 % of discharge capacity originating from the voltages below 0.5 V. In addition, the sugarcane biomass derived carbon displays an ultra-stable capacity with almost no attenuation even after 2000 cycles. In consideration of the low voltage plateau, we also calculated the relative energy density (ER, combination of the capacity and voltage plateau), and a high ER of 500 Wh kg-1 in the first cycle and 416 Wh kg-1 after 50 cycles are obtained. In situ TEM analysis was conducted to investigate the structural stability of sugarcane biomass derived carbon. Small volumetric changes are observed at different charge-discharge states, indicating the structural stability of our sugarcane biomass derived carbon during sodiation-desodiation process, which is conducive to the stable cycling of Na-ions.

Agricultural by-products offer attractive renewable feedstock options for the production of carbon to be used as electrode materials for energy storage applications. Developing insights into the carbonisation behaviour of these alternative feedstocks will enable us to tune the materials and processing conditions effectively. For the first time, this study reports the influence of lignocellulosic biomass variation on the structure and properties of sorghum-derived hard carbon materials. Four primary plant sections of sorghum biomass (leaf, sheath, upper stem and bottom stem), with different lignocellulosic composition and hierarchical native plant cell wall morphology, were partitioned from the harvested biomass and subsequently carbonised. Thermal and structural analysis of these sections before and after carbonisation revealed that both the morphology and associated lignocellulosic composition were influential upon the structure and properties of the resultant carbon. The leaf section with the highest lignin and ash content yielded 23% carbon, with high crystallinity and a higher existence of graphite-like domains. It also exhibited a highly porous structure and a large specific surface area. The sheath section with the highest cellulose content yielded 26% carbon with thinner graphitic layers and a larger d-spacing compared to other sections. Stem sections with high extractives facilitated early-stage stabilisation. The upper stem, which had the lowest lignin and ash content, yielded 25% carbon with the lowest BET surface area and pore volume. In contrast, the bottom stem yielded 30% carbon with more disordered turbostratic hard carbon and a lower d-spacing compared to other sections. It is noted that a higher graphitic carbon ratio can be achieved by selecting a biomass precursor with a higher lignin content and lower crystallinity index. Additionally, the value of BET surface area and pore volume strongly correlates with starting lignin content. This research contributes to developing a more sophisticated and comprehensive understanding of how the subtle structural and compositional variations present in different plant sections of sorghum biomass can influence the properties of carbonised materials, hopefully aiding the future potential for enhanced tunability of sustainable biomass-derived carbon products.

The organic fraction of municipal solid waste (OFMSW) and refuse-derived fuel (RDF) mainly consisting of paper/cardboard can be used as feedstock for the production of cellulosic ethanol. In this paper, an efficient technology is described to convert waste paper/cardboard into cellulosic ethanol. The process involves separation of the OF from the other components in the waste stream. An acid pretreatment is used to liberate the cellulosic fibers and the accessibility of the enzyme Cellic CTEC3 loading 3.75-11.25 FPU/g paper in a fed-batch addition up to 22.5% solid yield, 15 g sugars/l with a saccharification yield up to 90%. A semi-simultaneous fermentation process (SSFP) with a saccharomyces cerevisae strain MDS130 capable of fermenting both pentoses and hexoses are growing an ethanol titer (%v/v) of 8.4% on pilon-plant scale.

One of the key challenges for the industrial translation of cellulose nanofiber (CNF) materials is appropriate characterization and evaluation of product quality. Characterization of CNF properties is difficult because direct nanofiber assessment is largely unreliable and unscalable, while indirect characterization is often inaccurate and unable to be generalized across different biomass sources, processing routes, and final product or component formats. In addition, quality is an ambiguous term that is difficult to define, encompassing material performance, processing sustainability, and any aspects impacting economic viability of industrial production, dependent on the application in question. Using existing data on CNF produced from sorghum biomass, we explored the development of versatile statistical methodologies as a framework to investigate quality and sustainability, including: (a) a novel visualization tool for the evaluationof biomass processing sustainability (Processing Sustainability Triangle); (b) correlation analysis of biomass chemical composition with metrics relating to processing sustainability and nanopaper performance; and (c) an application-tunable Quality Ranking methodology based on a user-defined definition, as built through structural equation modeling. Versatility of the framework allows researchers and technologists to map the statistical methodology onto their experimental system of interest, enhancing data analysis through visualization. Ultimately,more sophisticated techniques for evaluation of product quality and processing sustainability will assist researchers to elucidate relationships in biomass-derived materialperformance and advance the industrial translation of CNF products.

This study provided important insights on the anaerobic digestion (AD) of hazelnut skin (HS) by operating a fed-batch AD reactor over 240 days and focusing on several factors impacting the process in the long term. An efficient reactor configuration was proposed to increase the substrate load while reducing the solid retention time during the fed-batch AD of HS. Raw HS produced maximally 19.29 mL CH4/g VSadd/d. Polyphenols accumulated in the reactor and the use of NaOH to adjust the pH likely inhibited AD. Maceration and methanol-organosolv pretreatments were, thus, used to remove polyphenols from HS (i.e. 82 and 97%, respectively) and improve HS biodegradation. Additionally, organosolv pretreatment removed 9% of the lignin. The organosolv-pretreated HS showed an increment in methane potential of 21%, while macerated HS produced less methane than the raw substrate, probably due to the loss of non-structural sugars during maceration.

Coconut Coir Pith (CCP) is a relatively unexplored type of lignocellulosic waste from the coconut industry. As a feedstock that is highly enriched in lignin (Klason lignin content of 40.9 wt % found in this study), CCP is a potential source for renewable lignin-derived materials. We have performed a systematic study on the characterization and valorization of lignin from CCP. We have investigated two different valorization approaches: reductive catalytic fractionation (RCF) and soda pulping followed by catalytic hydrodeoxygenation. During RCF, the lignin was converted into monomeric products in 7.6 wt %. Using soda pulping conditions, we were able to isolate lignin from CCP in 74% yield. Subsequent hydrotreatment of the lignin over a Pt/MoO3/TiO2 catalyst resulted in the formation of hydrogenated oil in 43 wt % yield, suitable for the production of biobased diesel fuels and lubricant base oils.

In this study, 18 animals were fed two forage-based diets: red clover (RC) and grass silage (GS), in a crossover-design experiment in which methane (CH4) emissions were recorded in respiration chambers. Rumen samples obtained through naso-gastric sampling tubes were analysed by NMR. Methane yield (g/kg DM) was significantly lower from animals fed RC (17.8 +/- 3.17) compared to GS (21.2 +/- 4.61) p = 0.008. In total 42 metabolites were identified, 6 showing significant differences between diets (acetate, propionate, butyrate, valerate, 3-phenylopropionate, and 2-hydroxyvalerate). Partial least squares discriminant analysis (PLS-DA) was used to assess which metabolites were more important to distinguish between diets and partial least squares (PLS) regressions were used to assess which metabolites were more strongly associated with the variation in CH4 emissions. Acetate, butyrate and propionate along with dimethylamine were important for the distinction between diets according to the PLS-DA results. PLS regression revealed that diet and dry matter intake are key factors to explain CH4 variation when included in the model. Additionally, PLS was conducted within diet, revealing that the association between metabolites and CH4 emissions can be conditioned by diet. These results provide new insights into the methylotrophic methanogenic pathway, confirming that metabolite profiles change according to diet composition, with consequences for CH4 emissions.

Thallium(I) (Tl(I)) pollution has become a pressing environmental issue due to its harmful effect on human health and aquatic life. Effective technology to remove Tl(I) ions from drinking water can offer immediate societal benefits especially in the developing countries. In this study, a bio-adsorbent system based on nitro-oxidized nanocellulose (NOCNF) extracted from sorghum stalks was shown to be a highly effective Tl(I) removal medium. The nitro-oxidation process (NOP) is an energy-efficient, zero-waste approach that can extract nanocellulose from any lignocellulosic feedstock, where the effluent can be neutralized directly into a fertilizer without the need for post-treatment. The demonstrated NOCNF adsorbent exhibited high Tl(I) removal efficiency (>90% at concentration < 500 ppm) and high maximum removal capacity (Qm = 1898 mg/g using the Langmuir model). The Tl(I) adsorption mechanism by NOCNF was investigated by thorough characterization of NOCNF-Tl floc samples using spectroscopic (FTIR), diffraction (WAXD), microscopic (SEM, TEM, and AFM) and zeta-potential techniques. The results indicate that adsorption occurs mainly due to electrostatic attraction between cationic Tl(I) ions and anionic carboxylate groups on NOCNF, where the adsorbed Tl(I) sites become nuclei for the growth of thallium oxide nanocrystals at high Tl(I) concentrations. The mineralization process enhances the Tl(I) removal efficiency, and the mechanism is consistent with the isotherm data analysis using the Freundlich model.

Acetone organosolv fractionation of beech and birch wood at the lab-scale results in high sugar yields from the (hemi)cellulose and the isolation of a high-purity lignin. In this study, the process is scaled up to validate the technology at the pilot scale using industrial-size beech and birch wood chips and low liquid-to-solid ratios as a next step toward commercialization. Translation of the fractionation process to the pilot-scale showed a similar performance as compared to the lab-scale processing with a good conversion of the wood polymeric pentoses to mostly monomeric sugars and a high delignification. Continuous lignin precipitation by solvent evaporation using the LigniSep process resulted in the formation of nonsticky lignin aggregates with a good filterability. The improved lignin yields and advanced process design as compared to the traditional dilutive lignin precipitation approaches are likely to translate to a better process economy. The pulp washing efficiency and the recovery of (nonprecipitable) lignin from the aqueous hemicellulose stream still need to be improved for an efficient process design. However, the fractionation performance and high product concentrations in the spent liquor provide an excellent start position for improved process design at the commercial scale.

The quality of wood powders depends on the size reduction technology used to produce them. The pre-drying, chipping, and conventional (impact and attritional) size reduction steps, commonly employed in industry, act to degrade wood and diminish its full potential as a renewable feedstock. In this study, the effect of using a new green (i.e. freshly harvested) milling technology, the multi-blade shaft mill (MBSM), on wood powder properties was investigated. Particle size distribution (PSD) and shape properties were measured by two-dimensional image analysis and surface area analysis was performed. The results showed that the MBSM can produce much finer powders compared to hammer milling, with particles demonstrating unique morphology and high specific surface area. Green wood milling yielded particles with the highest sphericity (0.64), aspect ratio (0.58), and micropore diameter (4.5 nm). Finer particles with spherical shapes enhanced the bulk density. Moreover, mill settings permit tailor-made powders according to the desired PSD.

Interest in the cultivation of Saccharina latissima is increasing in the north of Norway. In the present study, S. latissima was cultivated at two sites (Kraknes and Rotsund), 90 km apart, in Troms, northern Norway (69-70 N). The effect of site, depth, and sori origin (Kraknes and Rotsund) on S. latissima growth, biofouling, minerals, and potentially toxic elements (PTEs) content was studied. Large variations in the frond length and wet weight were observed between sites. The site with lower seawater temperature, higher nutrient levels and no freshwater influence (Kraknes) had better growth and later outbreak of epibionts. Sori origin had a significant effect on the growth only at the Kraknes site with S. latissima produced from the Kraknes sori having longer frond length and higher wet weight. The iodine content was, in general, high and increased with cultivation depth. The arsenic and cadmium content varied between sites and was lower than the recommended maximum level for food supplements in EU regulations. The present study shows that growth, biofouling, minerals, and PTEs content vary profoundly within the same geographical region and between sori origin, it thereby underlines the importance of site selection and using traits with high growth rates for seeding and cultivation to achieve maximum biomass.

Lignocellulosic materials (LMs) are abundant feedstocks with excellent potential for biofuels and biocommodities production. In particular, nut and coffee wastes are rich in biomolecules, e.g. sugars and polyphenols, the valorisation of which still has to be fully disclosed. This study investigated the effectiveness of ultrasounds coupled with hydrothermal (i.e. ambient temperature vs 80 C) and methanol (MeOH)-based pretreatments for polyphenols and sugar solubilisation from hazelnut skin (HS), almond shell (AS), and spent coffee grounds (SCG). The liquid fraction obtained from the pretreated HS was the most promising in terms of biomolecules solubilisation. The highest polyphenols, i.e. 123.9 (+/-2.3) mg/g TS, and sugar, i.e. 146.0 (+/-3.4) mg/g TS, solubilisation was obtained using the MeOH-based medium. However, the MeOH-based media were not suitable for direct anaerobic digestion (AD) due to the MeOH inhibition during AD. The water-based liquors obtained from pretreated AS and SCG exhibited a higher methane potential, i.e. 434.2 (+/-25.1) and 685.5 (+/-39.5) mL CH4/g glucosein, respectively, than the HS liquors despite having a lower sugar concentration. The solid residues recovered after ultrasounds pretreatment were used as substrates for AD as well. Regardless the pretreatment condition, the methane potential of the ultrasounds pretreated HS, AS, and SCG was not improved, achieving maximally 255.4 (+/-7.4), 42.8 (+/-3.3), and 366.2 (+/-4.2) mL CH4/g VS, respectively. Hence, the solid and liquid fractions obtained from HS, AS, and SCG showed great potential either as substrates for AD or, in perspective, for biomolecules recovery in a biorefinery context.

Globally, one in nine people suffer from undernourishment with evidence that this number is increasing. Additionally, due to the projected 50% increase in global population, the demand in worldwide animal-sourced protein is expected to double by 2050. Furthermore, not only are global animal protein supply chains susceptible to the effects of climate change, but they are also a significant contributor to greenhouse gas emissions and require large areas of arable land. Single cell proteins (SCPs) are an alternative protein source that offer a potential route to reduce the environmental impact of global protein consumption. One such SCP is Fusarium venenatum, which is a strain of mycoprotein widely sold under the brand name Quorn and is produced through the fermentation of the microorganism on glucose. However, this glucose still has a significant arable land-use burden associated with it. In order to mitigate this burden, sugars derived from agricultural lignocellulosic residues could be used, however, additional processing steps are required. In this work, exploratory research on fermentation of F. venenatum on sugars derived from lignocellulosic residues is presented. The food-grade ionic liquid [Ch][HSO4] was employed in combination with food-grade Celluclast 1.5L to extract glucose from rice straw residues, which resulted in an overall glucose yield of 42.4% compared to using non-food certified ionic liquid [TEA][HSO4], which yielded 92.8%. Based on these results, a Techno-Economic Analysis (TEA) and Life Cycle Assessment (LCA) were conducted after synthesising a biorefinery process model. TEA modelling outcomes highlighted that the crude mycoprotein paste product could be produced for $5.04 kg?1 ($40.04 per kg-protein). By conducting a retro-techno-economic analysis, it was shown that there is reasonable scope for reducing this price further by improving saccharification yields and utilising feedstocks with high cellulose contents. Furthermore, LCA results demonstrated significant sustainability benefits of lignocellulosic-derived mycoprotein, with greenhouse gas emissions less than 14% that of protein from beef. However, the most significant advantage of this technology is the minimal dependence on arable land compared to animal-sourced and plant-sourced proteins such as beef and tofu.

Anaerobically digested sewage sludge mixed with forest residues was pyrolysed at 800 C, at laboratory and pilot scale. The study quantified differences in char and gas yields for tests carried out in a simple fixed bed laboratory reactor and rotating retort pyrolyser at pilot scale, when the residence time of feedstock was 10 min in both cases. The yield of char from pilot scale was 4 % lower than from laboratory scale while the yield of gas was 15.7 % higher. During the pilot scale pyrolysis of anaerobically digested sewage sludge blended with forest residues the gas quality for energy recovery applications was assessed and the fate of impurities (tar, NH3 and H2S) was investigated. The raw pyrolysis gas contained 14.6 g/Nm3 of tar, 36.9 g/Nm3 of NH3 and 793 ppm of H2S. Sixteen N-containing tar species were identified of which pyridine, propenenitrile, 2-methyl-, benzonitrile, and indole are found to be the most abundant. The yield of N-containing tar compounds accounted for approx. 12 % of total tar content. Conditioned pyrolysis gas contained 7.1 g/Nm3 of tar, 0.036 g/Nm3 of NH3 and 119 ppm of H2S. Benzene was by far the most abundant tar compound followed by toluene and styrene. The specifications of the used internal combustion engine were exceeded due to the sum of tar compounds such as fluorantrene and pyrene with 4+ aromatic rings (at 0.0015 g/Nm3) and NH3 content The effectiveness and sustainability of energy recovery in wastewater treatment can be improved using forest industry by-products.

Adsorption of six contaminants of emerging concern (CECs) - caffeine, chloramphenicol, carbamazepine, bisphenol A, diclofenac, and triclosan - from a multicomponent solution was studied using activated biochars obtained from three lignocellulosic feedstocks: wheat straw, softwood, and peach stones. Structural parameters related to the porosity and ash content of activated biochar and the hydrophobic properties of the CECs were found to influence the adsorption efficiency. For straw and softwood biochar, activation resulted in a more developed mesoporosity, whereas activation of peach stone biochar increased only the microporosity. The most hydrophilic CECs studied, caffeine and chloramphenicol, displayed the highest adsorption (22.8 and 11.3 mg g-1) onto activated wheat straw biochar which had the highest ash content of the studied adsorbents (20 wt%). Adsorption of bisphenol A and triclosan, both relatively hydrophobic substances, was highest (31.6 and 30.2 mg g-1) onto activated biochar from softwood, which displayed a well-developed mesoporosity and low ash content.

Mercury contamination in drinking water is a worldwide problem due to its severely harming effects on the human body. A nanostructured natural bioadsorbent, carboxycellulose nanofiber extracted from raw moringa plant using the nitro-oxidation method (termed NOCNF), capable of effectively remediating this problem has been demonstrated. Nitro-oxidation is a simple approach that can extract carboxylated nanocellulose directly from raw biomass. In this study, the produced NOCNF contained a large density of carboxylate groups on the cellulose surface (0.97 mmol/g), capable of removing Hg2+ ions by simultaneous electrostatic-interactions and mineralization processes. Using the Langmuir analysis, the adsorption results indicated that the highest Hg2+ removal capacity of this NOCNF was 257.07 mg/g, which is higher than most of the reported values. The interactions between Hg2+ and NOCNF were further characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), transmission electron microscopy with electron diffraction and wide-angle X-ray diffraction methods, suggesting the existence of two distinct removal mechanisms: predominant adsorption at low Hg2+concentrations (?1000 ppm). The applications of NOCNF were illustrated in both suspension form, as an adsorbent/coagulant, and dry powder form using filtration column. The results indicated that NOCNF in suspension exhibited a higher maximum removal efficiency of 81.6% as compared to the dry state of 74.3%. This work demonstrated the feasibility of extracting nanostructured adsorbents from biomass feedstocks to tackle the Hg2+ contamination problem in drinking water.

Magnetic carbons can significantly lower the costs of wastewater treatment due to easy separation of the adsorbent. However, current production techniques often involve the use of chlorinated or sulfonated Fe precursors with an inherent potential for secondary pollution. In this study, ochre, an iron-rich waste stream was investigated as a sustainable Fe source to produce magnetic activated biochar from two agricultural feedstocks, softwood and wheat straw. Fe doping resulted in significant shifts in pyrolysis yield distribution with increased gas yields (+50%) and gas energy content (+40%) lowering the energy costs for production. Physical activation transformed ochre to magnetite/maghemite resulting in activated magnetic biochars and led to a 4-fold increase in the adsorption capacities for two common micropollutants - caffeine and fluconazole. The results show that Fe doping not only benefits the adsorbent properties but also the production process, leading the way to sustainable carbon adsorbents.

A study was conducted to identify optimal conditions (time and temperature) for heat pre-treatment of corn whole stillage (WS). Six samples of WS from different sources were divided into 13 sub-samples to give a total of 78 sub-samples. Thirteen treatments were applied to 13 sub-samples from each source (1 sub-sample/treatment). The treatments were untreated WS, and WS that was pre-treated (70 psi) for 10, 20, or 30 min and at 100, 120, 140, or 160 C in a 3 x 4 factorial treatment arrangement. Sub-samples were subjected to in vitro digestion with porcine pepsin and pancreatin, followed by in vitro fermentation for 72 h. Accumulated gas production was recorded and modeled to estimate kinetics of gas production. Heat pretreatment of WS at >= 120 C decreased (P < 0.05) its total dietary fiber (TDF) and chemically available lysine content by approximately 10 and 19 %, respectively; and increased (P < 0.05) total furans (TF) content from 0.50 to approximately 154 mg/kg. Pretreatment time and temperature interacted on TDF and TF content in WS, such that an increase in pretreatment time had no effect on TDF and TF content in WS when pretreated at 100, 120, or 140 C, but reduced (P < 0.05) TDF content and increased (P < 0.05) TF content in WS when pretreated at 160 C. Pretreatment time and temperature interacted (P < 0.05) on chemically available lysine content of WS, such that an increase in pretreatment time unaffected chemically available lysine content when the WS was pretreated at 100 or 120 C, but reduced (P < 0.05) chemically available lysine content when the WS was pretreated at 140 or 160 C. Pre-treatment time and temperature did not interact on in vitro disappearance of dry matter (IVD-DM), and total gas production. The coefficient of IVD-DM for untreated WS was 0.734. An increase in pre-treatment temperature from 0 to 160 C resulted in linear increase (P < 0.05) in coefficient of IVD-DM by 13 %, and of total gas production by 16 %. Response surface analysis indicated that maximum coefficient of IVD-DM and total gas production resulted from longer pretreatment times (20-30 min) and highest pretreatment temperature, whereas maximum chemically available lysine content resulted from pretreatment at 100 C for 20 min. In conclusion, the optimal conditions for pretreatment of WS for production of distillers dried grains with solubles of improved digestibility and fermentability by pigs were temperature of 140-160 C, and duration of approximately 20 min.

Solid-fuel stoves are at the heart of many homes not only in developing nations, but also in developed regions where there is significant deployment of such heating appliances. They are often operated inefficiently and in association with high emission fuels like wood. This leads to disproportionate air pollution contributions. Despite the proliferation of these appliances, an understanding of particulate matter (PM) emissions from these sources remains relatively low. Emissions from five solid fuels are quantified using a 'conventional' and an Ecodesign stove. PM measurements are obtained using both 'hot filter' sampling of the raw flue gas, and sampling of cooled, diluted flue gas using an Aerosol Chemical Speciation Monitor and AE33 aethalometer. PM emissions factors (EF) derived from diluted flue gas incorporate light condensable organic compounds; hence they are generally higher than those obtained with 'hot filter' sampling, which do not. Overall, the PM EFs ranged from 0.2 to 108.2 g GJ-1 for solid fuels. The PM EF determined for a solid fuel depends strongly on the measurement method employed and on user behavior, and less strongly on secondary air supply and stove type. Kerosene-based firelighters were found to make a disproportionately high contribution to PM emissions. Organic aerosol dominated PM composition for all fuels, constituting 50-65% of PM from bituminous and low-smoke ovoids, and 85-95% from torrefied olive stone (TOS) briquettes, sod peat, and wood logs. Torrefied biomass and low-smoke ovoids were found to yield the lowest PM emissions. Substituting these fuels for smoky coal, peat, and wood could reduce PM2.5 emissions by approximately 63%.

The drive towards a low carbon economy will lead to an increase in new lignocellulosic biorefinery activities. Integration of biorefinery waste products into established bioenergy technologies could lead to synergies for increased bioenergy production. In this study, we show that solid residue from the acid hydrolysis production of levulinic acid, has hydrochar properties and can be utilised as an Anaerobic Digestion (AD) supplement. The addition of 6 g/L solid residue to the AD of ammonia inhibited chicken manure improved methane yields by +14.1%. The co-digestion of biorefinery waste solids and manures could be a promising solution for improving biogas production from animal manures, sustainable waste management method and possible form of carbon sequestration

The goal of this research is to develop a partial delignification process for corn stover that simultaneously improves accessibility of enzymes to cellulose and recovers hydroxycinnamic acids (HCA) as a value-added product from the lignin. We recover HCAs from corn stover with a mild base extraction employing sodium hydroxide, ethanol, and water. The total HCA yield was 33.5 wt% on a lignin basis and approximately 6 wt% on a corn stover basis. This partial delignification pretreatment allowed 85 wt% of total available glucose to be recovered by enzymatic hydrolysis using an enzyme loading that is only 10% of the level recommended for recovering sugars from lignocellulosic biomass. Technoeconomic analysis indicates that recovery of HCAs could reduce the selling price of ethanol by $0.26 L-1. That part of the lignin not removed as HCA becomes a co-product of enzymatic hydrolysis suitable for thermochemical processing into additional biofuels and/or chemicals.

In this paper, we report the synthesis and characterization of pyrolyzed lignin compacts reinforced with 50 wt % wheat straw (WS) or sugar beet pulp (SBP) fibers. The compacts were pyrolyzed at 300, 500, 700, and 900 C in an Ar atmosphere. Detailed thermogravimetric analysis (TGA), thermomechanical analysis (TMA), Fourier transform infrared (FTIR) spectroscopy, and microstructure analysis were performed on these samples. FTIR analysis showed that pyrolysis of lignin-WS and lignin-SBP resulted in aromatic char. Scanning electron microscope (SEM) studies showed that foams obtained by pyrolyzing both lignin-50 wt % SBP and lignin-50 wt % WS composites have a cellular structure. X-ray tomography and energy-dispersive spectrometry (EDS) studies showed that pyrolysis of wheat straw caused the formation of mineral-rich nodules in the pyrolyzed lignin matrix, which was responsible for the denser and uniform microstructure of the lignin-WS composites. Due to this reason, the lignin-WS composites were denser and had a better mechanical strength as compared to the lignin-SBP composites. Both the compositions also showed temperature-dependent wettability behavior.

Miscanthus giganteous is probably the most fast growing and low nutrient bioenergy crop among lignocellulosic feedstocks. Despite its significant content in fermentable sugars, currently Miscanthus biomass is not used for biogas/methane production due to the high-lignin and low moisture content in the winter/spring harvest as well as cellulose crystallinity, which limit access to enzymatic action for all lignocellulosic feedstock. This study identified that a photocatalytic pretreatment prior to anaerobic digestion helps increase the substrate's biodegradability by oxidising the lignin fraction, leading to increased methane yield up to 46% compared to the untreated. A novel photocatalyst was manufactured by reactive magnetron-sputtering deposition of TiO2 particles onto natural zeolite supports, which provided important trace elements for the anaerobic digestion process and retained a large surface area that acted as biofilm to boost growth of the microbial community. A load of 2% w/w catalyst in the bioreactor after 3 h of photocatalytic treatment led to 220 mLN gVS-1, with a net energy balance that is achieved for the whole process when treating the dispersed phase suspension at concentrations above 10 g m-3.

The bioeconomy can play a critical role in helping countries to find alternative sustainable sources of products and energy. Countries with diverse terrestrial and marine ecosystems will see diverging feedstock opportunities to develop these new value chains. Understanding the sources, composition, and regional availability of these biomass feedstocks is an essential first step in developing new sustainable bio-based value chains. In this paper, an assessment and analysis of regional biomass availability was conducted in the diverse regions of Andalusia and Ireland using a bioresource mapping model. The model provides regional stakeholders with a first glance at the regional opportunities with regards to feedstock availability and an estimate of the transportation costs associated with moving the feedstock to a different modelled location/region for the envisioned biorefinery plant. The analysis found that there were more than 30 million tonnes of (wet weight) biomass arisings from Ireland (84,000 km2) with only around 4.8 million tonnes from the Andalusian region (87,000 km2). The study found that Cork in Ireland stood out as the main contributor of biomass feedstock in the Irish region, with animal manures making the largest contribution. Meanwhile, the areas of Almeria, Jaen, and Cordoba were the main contributors of biomass in the Andalusia region, with olive residues identified as the most abundant biomass resource. This analysis also found that, while considerable feedstock divergence existed within the regions, the mapping model could act as an effective tool for collecting and interpreting the regional data on a transnational basis.

The conversion of industrial crops to energy has received significant attention recently as a means to reduce carbon emissions and meeting the renewable energy targets. Samples of whole crop maize (Zea mays L.) were pre-treated in tap water using a novel microbubble-enhanced dielectric barrier discharge (DBD) plasma reactor that generates highly reactive species in situ and distribute them using microbubbles. The pre-treated maize was then used as feedstock in batch and continuously-fed mesophilic continuously-stirred anaerobic digesters (AD). Half of the pre-treated samples were washed in deionized water prior to feeding to assess the effect of possible inhibitory by-products generated during pre-treatment. In batch AD experiments, DBD-plasma pre-treated and washed maize produced 18% greater biogas production in comparison to untreated raw samples, and unwashed samples produced 29% lower biogas than the untreated samples. These results suggest the production of inhibitors to the AD process, but biogas production can be enhanced by removing these inhibiting compounds. Continuously-fed AD reactors exhibited no noticeable change in biogas output between raw and plasma-treated maize. For AD reactors operating in batch, or with a relatively long residence time and fed with high lignocellulose feedstocks, plasma-microbubble pre-treatment could enhance biogas output and process efficiency.

Synthetic rubber produced from nonrenewable fossil fuel requires high energy costs and is dependent on the presumed unstable petroleum price. Natural rubber latex (NRL) is one of the major alternative sustainable rubber sources since it is derived from the plant 'Hevea brasiliensis'. Our study focuses on integrating sustainably processed carboxycellulose nanofibers from untreated jute biomass into NRL to enhance the mechanical strength of the material for various applications. The carboxycellulose nanofibers (NOCNF) having carboxyl content of 0.94 mmol/g was prepared and integrated into its nonionic form (-COONa) for its higher dispersion in water to increase the interfacial interaction between NRL and NOCNF. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) analyses of NOCNF showed the average dimensions of nanofibers were length (L) = 524 +/- 203 nm, diameter (D) 7 +/- 2 nm and thickness 2.9 nm. Furthermore, fourier transform infra-red spectrometry (FTIR) analysis of NOCNF depicted the presence of carboxyl group. However, the dynamic light scattering (DLS) measurement of NRL demonstrated an effective diameter in the range of 643 nm with polydispersity of 0.005. Tensile mechanical strengths were tested to observe the enhancement effects at various concentrations of NOCNF in the NRL. Mechanical properties of NRL/NOCNF films were determined by tensile testing, where the results showed an increasing trend of enhancement. With the increasing NOCNF concentration, the film modulus was found to increase quite substantially, but the elongation-to-break ratio decreased drastically. The presence of NOCNF changed the NRL film from elastic to brittle. However, at the NOCNF overlap concentration (0.2 wt. %), the film modulus seemed to be the highest.

Pretreatments of lignocellulosic biomass prior to fast pyrolysis need to give a better yield and quality of pyrolysis oil and be practical to implement at a commercial scale. This study demonstrated, at a large pilot scale, that thermomechanical refining can reduce the particle size, hemicellulose content, and mineral content of pine wood chips, leading to improved yields of carbohydrate-derived chemicals on fast pyrolysis. Additionally, a hemicellulose-rich byproduct can be generated during the pretreatment for separate valorization. The impact of different presteaming times, citric acid infusion, and disc refining on the yield and composition of the pyrolysis oil was studied. Presteaming of citric acid-infused wood chips at 173 C for 3 min and refining to wood fiber proved most effective in improving the yield of pyrolysis oil organics, including the valuable biochemicals levoglucosan and hydroxyacetaldehyde, while reducing the yields of low-value char and noncondensable gases.

Catalytic hydropyrolysis of beech wood was conducted in a fluid bed reactor followed by a hydrodeoxygenation reactor with a sulfided NiMo/Al2O3 catalyst. In order to evaluate the effect of the catalyst in the fluid bed reactor, six different bed materials were tested. Conducting the hydropyrolysis using only the catalyst support materials MgAl2O4 or zeolite mixed with Al2O3 (H-ZSM-5-Al2O3) gave a high char and coke yield (18.7-21.1?wt.% dry ash free (daf)), CO and CO2 (18.9 and 20.0?wt.% daf), and low yield of condensed organics and C4+ gasses (17.8-20.4?wt.% daf). Using the supported catalysts CoMo/MgAl2O4 or NiMo/H-ZSM-5-Al2O3 significantly decreased the char yield to between 11.4 and 13.1?wt.% daf, while the condensed organics and C4+ yield increased to 21.5?wt.% daf for the CoMo/MgAl2O4 and 24.0?wt.% daf for the NiMo/H-ZSM-5-Al2O3. As an alternative to the (commercial) supported catalysts, a cheap natural mineral bog iron was tested as catalyst and gave a condensed organics and C4+ yield of 22.8?wt.% daf when pre-sulfiding the bog iron, while the yield was 24.7?wt.% daf when the bog iron was used un-sulfided, but reduced prior to the experiment. This indicates that bog iron is the most suitable catalyst in the fluid bed reactor.

The majority of the sludge from the treatment of wastewater in milk processing plants is land spread. The drawbacks of land spreading include local oversupply due to high transport costs, which results in sludge being spread on lands in the vicinity of the dairy factories. Local oversupply can lead to accumulation of certain substances in soil through annual application over many years. Therefore, in the long term, there is a need for alternative methods to recover energy and nutrients from increasing volumes of sludge generated from dairy processing. Pyrolysis offers a potential alternative to land spreading, which can reduce health and environmental risks, while providing an avenue for the recovery of energy and nutrients. Pyrolysis allows energy recovery in the form of a high calorific value pyrolysis gas and a char which may be used as a soil amendment. In this study pyrolysis of dried dairy sludge was carried out at pilot scale. The results indicate that a dried biological sludge can be successfully pyrolysed and when mixed with wood the resulting char meets European Biochar Certificate criteria regarding carbon content. Most of the initial energy content of the feedstock was retained in the pyrolysis gas prior to cleaning, 53%, compared to 34.5% in the char and 1.5% in the tar. For the pyrolysis gas after cleaning (mainly cracking in presence of air) the initial energy content of the feedstock retained in the gas was only slightly higher than that retained in the char, 39.2% versus 34.5%, while the tar accounted for 0.8% of the initial energy content.

Activated carbons are promising sorbents that have been heavily investigated for the physisorptive storage of hydrogen. The industrial process for production of activated carbons is finely tuned and requires a reliable and uniform feedstock. While the natural biopolymer lignin, a byproduct of several industries, has received increasing interest as a potentially sustainable and inexpensive activated carbon feedstock, the ratio of the three aromatic monomers (S, G, and H) in lignin can be heavily affected by the lignin source and growing conditions. The aromatic ratio is known to influence the thermal behavior of the polymer, which could be problematic for production of consistent activated carbons at scale. With the goal of improving the consistency of activated carbons produced from lignins derived from different feedstocks, here we present a route to limiting the influence of lignin feedstock on activated carbon porosity and performance, resulting in a carbonization process that is resilient to changes in lignin source. Two different types of organosolv lignin (representing high S-unit content and high G-unit content feedstocks) were investigated. Resulting activated carbons exhibited a high surface area (>1000 m2 g-1) with consistent adsorptive properties and reasonable hydrogen uptake of up to 1.8 wt % at 1 bar and -196 C. These findings indicate that low-temperature carbonization conditions can be used to produce a consistent carbon material using organosolv lignins from any source, paving the way for more widespread use of lignin in large-scale carbon production.

Large-scale production of biofuels and chemicals will require cost-effective, sustainable, and rapid deconstruction of woody biomass into its constituent sugars. Here, we introduce a novel two-step liquefaction process for producing fermentable sugars from red oak using a mixture of tetrahydrofuran (THF), water and dilute sulfuric acid. THF promotes acid-catalyzed solubilization of lignin and hemicellulose in biomass achieving 61% lignin extraction and 64% xylose recovery in a mild pretreatment step. The pretreatment opens the structure of biomass through delignification and produces a cellulose-rich biomass, which is readily solubilized at low temperature giving 65% total sugar yields in a subsequent liquefaction process employing the same solvent mixture. This process achieves competitive sugar yields at high volumetric productivity compared to conventional saccharification methods. THF, which can be derived from renewable resources, has several benefits as solvent including ease of recovery from the sugar solution and relatively low toxicity and cost.

This study examines the yields of solid residue and by-product from the microwave-assisted acid hydrolysis of lignocellulosic poplar wood for levulinic acid production. The aim of this study was to optimise levulinic acid production via response surface methodology (RSM) and also investigate the effect of reaction conditions on other products such as furfural, solid residue, formic acid and acetic acid yields. A maximum theoretical levulinic acid yield of 62.1% (21.0 wt %) was predicted when reaction conditions were 188 C, 126 min and 1.93 M sulphuric acid, with a corresponding solid residue yield of 59.2 wt %. Furfural from the hydrolysis of hemicellulose was found to have significantly degraded at the optimum levulinic acid yield conditions. The investigation of formic acid yields revealed lower formic acid yields than stoichiometrically expected, indicating the organic acid reactions under microwave-assisted hydrolysis of lignocellulose. The solid residue yields were found to increase significantly with increasing reaction time and temperature. The solid residue yields under all conditions exceeded that of levulinic acid and, therefore, should be considered a significant product alongside the high-value compounds. The solid residue was further examined using IR spectra, elemental analysis and XRF for potential applications. The overall results show that poplar wood has great potential to produce renewable chemicals, but also highlight all by-products must be considered during optimization.

This study compared the effects of hot-air pasteurisation (HAP) at 75-100 C versus autoclaving at 121 C and 2 bar overpressure on the lignocellulosic degradation process of birch-based substrates that were used for shiitake mushroom cultivation and potential bioethanol production. Fifty substrate samples were obtained as a time series from different stages of the cultivation, and their chemical contents were measured by chemical analysis and near infra-red spectroscopy (NIR). Despite of different energy intensities, HAP and autoclaving did not result in significant differences in the degradation of lignin and carbohydrates. Major compositional changes were associated with the cultivation process. Principal component analysis on the wet chemical data and orthogonal projections to latent structures based on NIR spectra reached the same conclusion, namely that HAP had similar effect as autoclaving on compositional changes in the substrate during cultivation. The results of this study suggest that a substitution of autoclaving by HAP may potentially save up to 9.9 TWh energy for the global production of 7.5 million ton shiitake. At the same time, lignocellulose feedstock can be pretreated for the production of up to 3.24 million m3 of 95%-ethanol fuels, which can potentially substitute proximate 1.88 million m3 of regular gasoline.

Catalytic hydropyrolysis of beech wood has been conducted in a fluid bed reactor at 450 C with a sulfided CoMo catalyst followed by a fixed bed hydrodeoxygenation (HDO) reactor with a sulfided NiMo catalyst at hydrogen pressures between 3.0 and 35.8 bar. Using both reactors the condensable organic yield (condensed organic and C4+ in gas) varied between 18.7 and 21.5 wt% dry ash free basis (daf) and was independent of the hydrogen pressure. At 15.9 bar hydrogen or higher the condensed organic phase was essentially oxygen free (<0.01 wt% dry basis (db)), but decreasing the hydrogen pressure to 3.0?bar increased the oxygen content to 7.8 wt% db. The char and coke yield was close to constant (11.0-12.7 wt% daf) at hydrogen pressures between 15.9 and 35.8 bar, but increased to 15.7 wt% at 3.0 bar hydrogen due to an increase in the polymerization of pyrolysis vapors. The measured carbon content on the spent catalysts from both the fluid bed and HDO reactor showed that coking of the catalysts increased when the hydrogen pressure was decreased below 15.9 bar. The increased coking at low hydrogen pressure (<15.9 bar) was ascribed to the polymerization of the more reactive oxygenates produced in the fluid bed reactor.

In the present paper, we introduce an end-to-end workflow called joint and unique multiblock analysis (JUMBA), which allows multiple sources of data to be analyzed simultaneously to better understand how they complement each other. In near-infrared (NIR) spectroscopy, calibration models between NIR spectra and responses are used to replace wet-chemistry methods, and the models tend to be instrument-specific. Calibration-transfer techniques are used for standardization of NIR-instrumentation, enabling the use of one model on several instruments. The current paper investigates both the similarities and differences among a variety of NIR instruments using JUMBA. We demonstrate JUMBA on both a previously unpublished data set in which five NIR instruments measured mushroom substrate and a publicly available data set measured on corn samples. We found that NIR spectra from different instrumentation largely shared the same underlying structures, an insight we took advantage of to perform calibration transfer. The proposed JUMBA transfer displayed excellent calibration-transfer performance across the two analyzed data sets and outperformed existing methods in terms of both prediction accuracy and stability. When applied to a multi-instrument environment, JUMBA transfer can integrate all instruments in the same model and will ensure higher consistency among them compared with existing calibration-transfer methods.

Levoglucosan has significant potential in commercial applications for the synthesis of polymers, solvents and pharmaceuticals. It is currently overlooked for commercial applications due to its high cost of synthesis and purification. We have developed a system to produce pure crystals of levoglucosan based on the fast pyrolysis of lignocellulosic biomass. A novel bio-oil recovery system concentrated levoglucosan along with other anhydrosugars, sugars and phenolic compounds in a non-aqueous 'heavy ends' fraction. Liquid-liquid water extraction separated sugar-rich solubilized carbohydrates from non-soluble phenolic compounds. The solubilized carbohydrate fraction, contaminated with partially soluble phenolic monomers, was filtered through Sepabeads SP207 adsorption resin to produce clarified juice. The composition of the clarified juice on a dry basis after resin filtration and rotary evaporation was 81.2% sugars, 4.45-4.60% volatile non-sugar, 1.71% carboxylic acids and 12.5-12.6% unidentified compounds, which was sufficiently pure to crystallize the sugars by evaporation. A cold solvent rinse of the crystal mass separated and purified levoglucosan from other sugars. Levoglucosan purity was 102.5% +/- 3.109% at the 99% confidence level. Techno-economic analysis of a plant pyrolyzing 250 tonne per day of pretreated biomass to produce cellulosic sugars indicated a minimum selling price (MSP) for pure levoglucosan crystals of $1333 per MT, which is less than one-tenth its current average market price. Operating hours of the plant, fermentable syrup yield and fixed capital are the most significant parameters affecting MSP.

Laminaria. sp. seaweeds have been recognised the potential to greatly contribute to the generation of renewable gaseous fuel via anaerobic digestion. Seaweed feedstock has been documented to consistently vary its biochemical composition with seasons, which affects stability of biomethane production. As currently seaweeds are too costly for use as third generation feedstock for biofuels, this paper investigates the biogas potential of the algal waste streams from the existing bio-industry. Analytical tests identified an improved digestibility of extracted residues (C:N>20). Fermentation with and without inoculum acclimatation revealed the interaction between compositional seasonality and inoculum type to significantly affect methane production from the extracted samples. Summer's composition has the most significant impact on methane production, with best results achieved with acclimatised inoculum (433ml CH4 gVS-1 and final biodegradation of about 90%). Organics concentration (tCOD) and ash:volatile (A:V) ratio also play a major role in the bioconversion process. In particular, digestion with acclimatised inoculum better responds to A:V fluctuations across seasons, which produced the highest average methane yield of 334ml gVS-1. Pretreatments are required to increase the biodegradation index in spring and summer when not using acclimatation.

The main goal of this work was to determine the differences in the composition of the surface and bulk of lignocellulosic feedstock subjected to torrefaction. Miscanthus x giganteus and Willow were used as widely available types of second generation of biomass. The surface of the samples was primarily characterized by time-of-flight secondary ion mass spectrometry. The bulk of the investigated biomass was analyzed by Fourier transform infrared spectroscopy, thermogravimetry and classical chemical methods. The results obtained show that the destruction of the surface of both Miscanthus x giganteus and Willow begin at lower temperature than that observed for the bulk. Moreover, in the case of Miscanthus x giganteus the possibility of the partial surface decomposition of not only the hemicellulose and cellulose but also lignin structure is pointed out. The observed differences between the behavior of the uppermost and deeper layers of the studied biomass samples indicate that the efficiency of their thermal degradation is different and should be taken into account when discussing the torrefaction process.

Catalytic hydropyrolysis of beech wood was conducted in a fluid bed reactor at 450 C and a total pressure of 26 bar. The differences in hydrodeoxygenation activity, selectivity, and the resulting product compositions between sulfided Mo/MgAl2O4, CoMo/MgAl2O4, and NiMo/MgAl2O4 catalysts have been investigated. The acidity and molybdate species in the oxide catalyst precursors were characterized with ammonia temperature programmed desorption and Raman spectroscopy. The spent sulfided catalysts were also extensively characterized by scanning electron microscopy (SEM) and by scanning transmission electron microscopy (STEM) coupled with energy dispersive X-ray spectroscopy (EDS). The catalytic hydropyrolysis of beech wood produced four kinds of products: Liquid organic and aqueous phases, solid char, and gases. The solid char and aqueous phase yields were not affected by the type of catalyst. The sum of condensed organics and C4+ gas yield varied between 24.3 and 26.4 wt % on dry, ash free basis (daf) and was highest for the Mo catalyst and lowest for the NiMo catalyst. The NiMo catalyst had the highest hydrogenation, cracking, and decarbonylation activity. The oxygen content in the condensed organic phase was between 9.0 and 12 wt % on dry basis (db) and was lowest for the CoMo catalyst and highest for the Mo catalyst. The carbon recovery in the condensable organics was 39% for both the CoMo and the Mo, and 37% for the NiMo catalyst. These results indicate that the CoMo, due to its high deoxygenation activity and high carbon recovery, is the most suitable catalyst for catalytic hydropyrolysis. The carbon content on the spent CoMo was between 1.5 and 3.3 wt % and between 0.9 and 3.1 wt % on the spent NiMo catalyst, but between 5.0 and 5.5 wt % on the spent Mo catalyst. The higher carbon content on the spent Mo catalyst was probably due to its lower deoxygenation and hydrogenation activity. Calcium particles and small amounts of potassium (<=1.5 wt %) were detected on all spent catalysts using STEM-EDS, showing that alkali metals are transferred from the biomass to the catalyst, which potentially could lead to catalyst deactivation.

Peatlands occupy 20% of the land area of Ireland and store over half of soil carbon stocks. Over 80% of these peatlands have been disturbed by human activity such as drainage for peat extraction, afforestation and agriculture. In this study, peat samples were collected from 12 horticultural peat extraction sites in the Irish midlands. The carbon (C), nitrogen (N), hydrogen and sulphur content were determined, and from these, the carbon oxidation state (Cox) and oxidative ratio (OR) were calculated. The carbon oxidation ratio reflects organic matter synthesis and degradation, and is thus an important parameter in understanding terrestrial carbon cycling, whilst OR represents the molar ratio of oxygen (O2) and carbon dioxide (CO2) fluxes associated with net ecosystem exchange. Elemental concentrations and ratios were typical for Irish horticultural peat (e.g. carbon concentrations 54%-57%), though showed site to site variability. Cox and OR values varied between -0.22 and -0.11, and 1.04 and 1.07, respectively, and were comparable to United Kingdom peat soils. All values for OR were lower than 1.1, the value commonly used in global CO2 partitioning studies. Further research should investigate OR values in peatland which has not been studied to date. Across all sites, measures of increased decomposition (i.e. C/N ratios) significantly correlated with increasing OR reflecting more reduced organic matter. This study provides data in temperate peat soils that increases the coverage of Cox and OR values and will inform global CO2 partitioning studies.

Eucalypts can be very productive when intensively grown as short rotation woody crops (SRWC) for bioproducts. In Florida, USA, a fertilized, herbicided, and irrigated cultivar planted at 2471 trees/ha could produce over 58 green mt/ha/year in 3.7 years, and at 2071 trees/ha, its net present value (NPV) exceeded $750/ha at a 6% discount rate and stumpage price of $11.02/green mt. The same cultivar grown less intensively at three planting densities had the highest stand basal area at the highest density through 41 months, although individual tree diameter at breast height (DBH) was the smallest. In combination with an organic fertilizer, biochar improved soil properties, tree leaf nutrients, and tree growth within 11 months of application. Biochar produced from Eucalyptus and other species is a useful soil amendment that, especially in combination with an organic fertilizer, could improve soil physical and chemical properties and increase nutrient availability to enhance Eucalyptus tree nutrition and growth on soils. Eucalypts produce numerous naturally occurring bioproducts and are suitable feedstocks for many other biochemically or thermochemically derived bioproducts that could enhance the value of SRWCs.

This study investigates the effect of high-temperature pyrolysis and post-treatment processes on spruce and oak charcoal yields and CO2 reactivity in a slow pyrolysis reactor. Post-treatment processes such as co-pyrolysis of biomass and recirculated tar mixture with that to the distillation of the charcoal-tar blend gave similar increase in charcoal yields. From a technological standpoint, co-pyrolysis of charcoal and tar mixture decreased the CO2 reactivity of the charcoal approaching that of fossil-based coke. This emphasize the importance of tar addition and high temperature treatment on charcoal properties. Moreover, the findings of this work show the potential use of the tar organic fractions as a binder that can be used for the charcoal pellet preparation. The results are promising as they show that the charcoal-based pellets have comparable properties of pellets from herbaceous biomass leading to the cost reduction in charcoal transportation and storage.

Hot-air (75-100 C) pasteurisation (HAP) of birch-wood-based substrate was compared to conventional autoclaving (steam at 121 C) with regard to shiitake growth and yield, chemical composition of heat-pretreated material and spent mushroom substrate (SMS), enzymatic digestibility of glucan in SMS, and theoretical bioethanol yield. Compared to autoclaving, HAP resulted in faster mycelial growth, earlier fructification, and higher or comparable fruit-body yield. The heat pretreatment methods did not differ regarding the fractions of carbohydrate and lignin in pretreated material and SMS, but HAP typically resulted in lower fractions of extractives. Shiitake cultivation, which reduced the mass fraction of lignin to less than half of the initial without having any major impact on the mass fraction of glucan, enhanced enzymatic hydrolysis of glucan about four-fold. The choice of heating method did not affect enzymatic digestibility. Thus, HAP could substitute autoclaving and facilitate combined shiitake mushroom and bioethanol production.

Triodia, an endemic Australian grass genus of ?70 species inhabiting arid and monsoonal regions, is an abundant and underused biomass resource. Harsh environmental conditions have driven the evolution of adaptive extremophile traits, including uniquely high aspect ratio cellulose nanofibres (CNFs) and high hemicellulose content. In this study, we advance understanding of CNFs by comparing three Triodia species (four ecotypes) grown in their natural desert habitat or cultivated in an irrigated farm setting. We evaluated biomass production, morphological and biochemical responses to these contrasting growth environments, and analysed the properties of fabricated nanopaper to assess the impact of species and growth environment on the material properties. We hypothesised that growing Triodia plants in well-watered and fertilised cultivation would relax arid environmental cues and may result in less desirable material properties. Contrary to our hypothesis, nanopaper derived from cultivated plants showed no regression in material properties compared to plants grown in their natural habitat. For instance, we found: (1) cultivated 'soft' species had a daily yield of greater than 2?g of dry biomass per plant; (2) three of the four ecotypes tested had higher hemicellulose contents in cultivation; (3) and with this higher hemicellulose content, the biomass proved to be more amenable to fibrillation, as cultivated plants achieved a lower average fibre diameter product. Overall, this study adds to the existing knowledge on the material properties of the Australian desert grass Triodia and the potential for production in agronomic settings. Understanding and potentially manipulating the traits of Australian desert grasses for beneficial material properties will accelerate the development of bio-based products in the future.

This study presents the effect of lignocellulosic compounds and monolignols on the yield, nanostructure and reactivity of soot generated at 1250 C in a drop tube furnace. The structure of soot was characterized by electron microscopy techniques, Raman spectroscopy and electron spin resonance spectroscopy. The CO2 reactivity of soot was investigated by thermogravimetric analysis. Soot from cellulose was more reactive than soot produced from extractives, lignin and monolignols. Soot reactivity was correlated with the separation distances between adjacent graphene layers, as measured using transmission electron microscopy. Particle size, free radical concentration, differences in a degree of curvature and multi-core structures influenced the soot reactivity less than the interlayer separation distances. Soot yield was correlated with the lignin content of the feedstock. The selection of the extraction solvent had a strong influence on the soot reactivity. The Soxhlet extraction of softwood and wheat straw lignin soot using methanol decreased the soot reactivity, whereas acetone extraction had only a modest effect.

The industrial platform chemicals 5-hydroxymethylfurfural (HMF) and furfural (FF) were produced from mixed mono- and oligosaccharides in a hydrolysate obtained from the prehydrolysis of radiata pine wood chips. The conversions were performed at high temperatures in an autoclave using either a THF/water biphasic system under both Bronsted and Lewis acid catalysis provided by NaHSO4/ZnSO4, or an acetone/water biphasic system under Bronsted acid catalysis afforded by H3PO4. Treatment in a THF/water system at 160 C for 90min gave the highest yields of HMF (40 molar%) and FF (58 molar%), while the best conditions for the acetone-water system were 180 C/80min for HMF (36 molar%) and 170 C/30min for FF (62% molar%). Yields for HMF and FF were based on respective hexose and pentose saccharide contents of the solids. The results show that mixed saccharide by-products of thermo-mechanical pulping can be converted into furans at moderately high yields by both catalytic systems.

Very recently, integrated biorefinery approaches are being developed with the aim to produce high-value products for a variety of industries in conjunction with green energy from sustainable biomass. Macroalgae (seaweed) have been regarded as more sustainable compared to terrestrial crops, since they do not occupy land for growth. Macroalgal biomass changes greatly according to species and harvest season, which affects its chemical energy potential. This study was conducted seasonally on five species of brown seaweed over a yearlong period to investigate the effects of chemical composition variations, bioproducts extraction processes and inoculum acclimatation on methane production. As a result of the bioproducts extraction, it was found the seaweed residues exhibit a great potential to produce methane. Stoichiometric methane yield and C:N ratio changed in favour of an improved digestibility with bioconversion rates greater than 70% in some instances, i.e. achieved by Laminaria species and on the West coast Fucus serratus. The two Laminaria species investigated also presented the highest CH4 production rate, with Laminaria digitata reaching 523?mL CH4 gVS-1 and L. saccharina peaking at 535?mL CH4 gVS-1 with acclimatised and non-acclimatised sludge respectively.

A catalytic process for the upgrading of woody biomass into mono-aromatics, hemi-cellulose sugars and a solid cellulose-rich carbohydrate residue is presented. Lignin fragments are extracted from the lignocellulosic matrix by cleavage of ester and ether linkages between lignin and carbohydrates by the catalytic action of homogeneous Lewis acid metal triflates in methanol. The released lignin fragments are converted into lignin monomers by the combined catalytic action of Pd/C and metal triflates in hydrogen. The mechanism of ether bond cleavage is investigated by lignin dimer models (benzyl phenyl ether, guaiacylglycerol-?-guaiacyl ether, 2-phenylethyl phenyl ether and 2-phenoxy-1-phenylethanol). Metal triflates are involved in cleaving not only ester and ether linkages between lignin and the carbohydrates but also B-O-4 ether linkages within the aromatic lignin structure. Metal triflates are more active for ?-O-4 ether bond cleavage than Pd/C. On the other hand, Pd/C is required for cleaving ?-O-4, 4-O-5 and B-B linkages. Insight into the synergy between Pd/C and metal triflates allowed optimizing the reductive fractionation process. Under optimized conditions, 55 wt% mono-aromatics - mainly alkylmethoxyphenols - can be obtained from the lignin fraction (23.8 wt%) of birch wood in a reaction system comprising birch wood, methanol and small amounts of Pd/C and Al(III)-triflate as catalysts. The promise of scale-up of this process is demonstrated.

gnocellulosic materials from municipal solid waste emerge as attractive resources for anaerobic digestion biorefinery. To increase the knowledge required for establishing efficient bioprocesses, dynamics of batch fermentation by the cellulolytic bacterium Ruminiclostridium cellulolyticum were compared using three cellulosic materials, paper handkerchief, cotton discs and Whatman filter paper. Fermentation of paper handkerchief occurred the fastest and resulted in a specific metabolic profile: it resulted in the lowest acetate-to-lactate and acetate-to-ethanol ratios. By shotgun proteomic analyses of paper handkerchief and Whatman paper incubations, 151 proteins with significantly different levels were detected, including 20 of the 65 cellulosomal components, 8 non-cellulosomal CAZymes and 44 distinct extracytoplasmic proteins. Consistent with the specific metabolic profile observed, many enzymes from the central carbon catabolic pathways had higher levels in paper handkerchief incubations. Among the quantified CAZymes and cellulosomal components, 10 endoglucanases mainly from the GH9 families and 7 other cellulosomal subunits had lower levels in paper handkerchief incubations. An in-depth characterization of the materials used showed that the lower levels of endoglucanases in paper handkerchief incubations could hypothetically result from its lower crystallinity index (50%) and degree of polymerization (970). By contrast, the higher hemicellulose rate in paper handkerchief (13.87%) did not result in the enhanced expression of enzyme with xylanase as primary activity, including enzymes from the 'xyl-doc' cluster. It suggests the absence, in this material, of molecular structures that specifically lead to xylanase induction. The integrated approach developed in this work shows that subtle differences among cellulosic materials regarding chemical and structural characteristics have significant effects on expressed bacterial functions, in particular the cellulolysis machinery, resulting in different metabolic patterns and degradation dynamics.