Analysis Package P33 : Ultimate (Elemental) Analysis

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.

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.

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

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.

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.