Analysis of Feedstocks for the Production of Biochar
There are two key considerations when producing biochar from biomass:
1. Biochar Yield - Defined as the percentage by mass of the original biomass that ends up as biochar.
2. Biochar Quality - A wide-encompassing term that considers how suitable the physical and chemical properties of the biochar are for the desired end-use.
Both of these parameters are affected by the conditions under which the feedstock is pyrolysed. These conditions include temperature, heating rate, and residence time. For example, high temperatures will lead to lower yields of biochar, as more of the biomass becomes volatile at higher temperatures, but can also result in the formation of a biochar of higher quality for certain applications (for example those that require a material of a higher carbon content).
How Feedstocks can Influence Biochar Yield and Quality
Under this assumption, it is useful to consider how each of the main constituents of biomass behave when exposed to prolysis conditions.
Cellulose
Lignocellulosic biomass feedstocks are the most abundant type of biomass. They are primarily composed of lignin and the polysaccharides cellulose and hemicellulose, along with smaller amounts of extractives and ash.Cellulose undergoes a series of stages of degradation in the pyrolysis process, starting with dehydration at lower temperatures (100 to 200 oC), followed by depolymerisation at temperatures of 314 to 400 oC, with carbonisation leading to biochar production at temperatures over 400 oC. Cellulose is mostly volatile in slow-pyrolysis conditions meaning that much of the polymer will end up in the (non-condensible) gas rather than the biochar.
Hemicellulose
While cellulose is a homopolymer composed of only one sugar (glucose), hemicellulose is a complex polysaccharide that can contain other sugars. There are a number of different types of hemicellulose, these differ according to the sugar units that constitute the main backbone of the polymer as well as according to the amount and composition of the side-groups attached to this backbone.Due to their heterogeneity, different hemicelluloses behave in different ways in slow-pyrolysis. However, in general, hemicellulose degrades at a lower temperature (220 to 315 oC) than cellulose. Given the more volatile nature of this polysaccharide, biochar yields from hemicellulose are even lower than from cellulose, with the majority of the material ending up in the (non-condensable) gas.
Lignin
lignin is a highly heterogeneous cross-linked polymer composed of aromatic subunits. It has a higher carbon content than cellulose and hemicellulose and also experiences a more gradual profile for decomposition than these polymers, with the temperature range being 250 to 500 oC. There are characteristic differences in lignin composition between hardwoods, softwoods, and herbaceous feedstocks.Lignin typically produces higher biochar yields than cellulose and hemicellulose, with lesser amounts of the polymer ending up in the gas or liquid fractions.
Extractives
Extractives are defined as extraneous components that may be separated from the insoluble cell wall material by their solubility in water or neutral organic solvents. Solvents of different polarities are required to remove different types of extractives. Hence the extractives are often classified according to which solvent can extract them (e.g. ethanol-soluble-extractives).Generally, extractives are more volatile than the structural components of biomass (cellulose, hemicellulose, and lignin) and therefore undergo thermal degradation at lower temperatures. This means that the majority of the extractives are likely to go to gas, rather than biochar, production in slow pyrolysis.
Protein
Different proteins have varying thermal stabilities and undergo different thermal degradation pathways during pyrolysis. Furthermore, the presence of nitrogen-containing compounds resulting from protein pyrolysis can have implications for the use of biochar as a soil amendment. Nitrogen is an essential nutrient for plant growth, and biochar produced from nitrogen-rich biomass can be a source of plant-available nitrogen in soil. However, the availability of nitrogen from biochar can vary depending on the pyrolysis conditions and the specific nitrogen-containing compounds formed during pyrolysis.
Ash
Ash wil be retaining in the biochar as it will not become volatile under the conditions employed for slow-pyrolysis. However, during pyrolysis, ash does undergo thermal transformation, which leads to the formation of a range of compounds, including oxides, carbonates, and silicates. At higher temperatures, ash undergoes more rapid thermal transformation, leading to a higher yield of oxides and silicates. Conversely, at lower temperatures, ash undergoes slower thermal transformation, leading to a higher yield of carbonates.The presence of ash in biochar can have implications for its use as a soil amendment. Ash can be a source of plant nutrients, such as potassium, calcium, and magnesium, which can enhance plant growth. However, ash can also contain potentially toxic elements, such as heavy metals, which can accumulate in soil and pose a risk to plant and human health. Hence, it is important that the composition of ash and the potential presence of toxic elements should be considered when selecting biomass feedstocks for biochar production.
Lignocellulosic Composition
At Celignis we offer a wide range of lignocellulose analysis packages (as detailed here), however for the evaluation of candidate feedstocks for biochar production we would recommend packages P10 or P19, as detailed here.
Total Sugars, Glucose, Xylose, Mannose, Arabinose, Galactose, Rhamnose, Lignin (Klason), Lignin (Acid Soluble), Acid Insoluble Residue, Extractives (Ethanol-Soluble), Extractives (Water-Soluble), Extractives (Exhaustive - Water then Ethanol), Extractives (Water-Insoluble, Ethanol Soluble) , Ash, Ash (Acid Insoluble)
Total Sugars, Glucose, Xylose, Mannose, Arabinose, Galactose, Rhamnose, Lignin (Klason), Lignin (Klason - Protein Corrected), Lignin (Acid Soluble), Acid Insoluble Residue, Extractives (Ethanol-Soluble), Extractives (Water-Soluble), Extractives (Exhaustive - Water then Ethanol), Extractives (Water-Insoluble, Ethanol Soluble) , Ash, Ash (Acid Insoluble), Glucuronic Acid, Galacturonic Acid, 4-O-Methyl-D-Glucuronic Acid, Protein Content of Acid Insoluble Residue, Carbon Content of Acid Insoluble Residue, Hydrogen Content of Acid Insoluble Residue, Nitrogen Content of Acid Insoluble Residue, Sulphur Content of Acid Insoluble Residue, Xylitol, Sucrose, Fructose, Sorbitol, Trehalose
Request a QuoteLignocellulose
Major and Minor Elements
For example, the European Biochar Certificate (EBC), an organisation set up to ensure the quality and safety of biochar produced in Europe, sets thresholds for the upper limits for the amounts of certain heavy metals in biochar. These threshold values vary according to the planned end-use of the biochar. For example, the limit for the arsenic content of biochar to be used in animal feed applications is 2ppm whilst this limit rises to 13ppm if the biochar is to be used in consumer biomaterials.
At Celignis we can profile your potential biochar feedstocks for their major and minor elements and then, based on an estimate of the expected biochar yield, the expected amount of each element in the resulting biochar can be calculated. For example, if your feedstock has a zinc content of 20ppm and it is expected that the biochar yield would be 20%, then the zinc content of the final biochar can be estimated to be 100pm.
Such expected values can then be compared against threshold upper limits, from EBC or other institutions, to see if the resulting biochar would qualify for the desired end-use.
Such a pre-screening approach would be much more cost-effective than producing a biochar sample and then analysing it for its heavy metals contents.
Request a QuoteHeavy Metals
Ultimate Analysis and Protein Content
We have a number of analysis packages that can determine the carbon content of a feedstock using the Dumas analysis method. This method also allows for the determination of the hydrogen, nitrogen, and sulphur contents, with the oxygen content calculated by difference (considering the ash also present).
The determination of nitrogen content of the feedstock is also important when considering the targetted end-use for the biochar, particularly if soil-amendment is being considered. Protein content can be estimated from the nitrogen content by multiplying it by a conversion factor relevant to the type of feedstock (for example a factor of 6.25 is used for many types of biomass). However, if a greater understanding of the protein composition of the feedstock is required then we can analyse the sample for its amino acid composition (package P17).
Volatile Matter, Fixed Carbon, Moisture, Ash, Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen, Gross Calorific Value, Net Calorific Value, Chlorine, Ash Shrinkage Starting Temperature (Reducing), Ash Deformation Temperature (Reducing), Ash Hemisphere Temperature (Reducing), Ash Flow Temperature (Reducing), Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium
Request a QuoteUltimate Analysis
If nitrogen is used then the sample will be heated under pyrolysis conditions (i.e. with no oxygen). This means that estimates can be made for the potential biochar yield at a given temperature or that a pyrolysis temperature can be selected for a particular yield of biochar.
TGA is a cost-effective method for screening potential biochar feedstocks for their behaviours under pyrolysis conditions without having to produce biochar in a pyrolysis reactor.
Relevant packages for the thermogravimetric analysis of feedstocks are listed below:
Thernogram - Under Nitrogen, Thermogram - Under Air, Moisture, Inherent Moisture, Ash Content (815C), Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen, Organic Carbon, Inorganic Carbon, Chlorine, Volatile Matter, Fixed Carbon, Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium, Gross Calorific Value, Net Calorific Value, Ash Shrinkage Starting Temperature (Reducing), Ash Deformation Temperature (Reducing), Ash Hemisphere Temperature (Reducing), Ash Flow Temperature (Reducing)
Thernogram - Under Nitrogen, Thermogram - Under Air, Moisture, Inherent Moisture, Ash Content (815C), Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen, Organic Carbon, Inorganic Carbon, Chlorine, Volatile Matter, Fixed Carbon, Specific Surface Area (Nitrogen Gas Adsorption), Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium, Gross Calorific Value, Net Calorific Value, Ash Shrinkage Starting Temperature (Reducing), Ash Deformation Temperature (Reducing), Ash Hemisphere Temperature (Reducing), Ash Flow Temperature (Reducing)
Click here to read more about the thermogravimetric analysis of biomass.
Sajna KV
Bioanalysis Developer
PhD
Our Biomass Detective! Designs, tests, optimizes and validates robust analytical methods for properties of relevance to the various biochar market applications.
Dan Hayes
Celignis CEO And Founder
PhD (Analytical Chemistry)
Dreamer and achiever. Took Celignis from a concept in a research project to being the bioeconomy's premier provider of analytical and bioprocessing expertise.
Edgar Ramirez Huerta
Biochar Project Developer
MSc
Has taken a major role in developing Celignis's capabilities for biochar analysis and project development. His thesis covered the evaluation of high value applications for high-carbon materials.
Global Recognition as Biomass and Biochar Experts
Biochar Production
Biochar Analysis
Biochar Combustion Properties
Soil Amendment & Plant Growth Trials
Analysis of PAHs in Biochar
Surface Area and Porosity of Biochar
Thermogravimetric Analysis of Biochar
Biochar Upgrading
Biochar for Carbon Sequestration
Technoeconomic Analyses of Biochar Projects
Research Project Collaborations
See our pitches for the 2024 topics.
Lignin (Klason), Lignin (Acid Soluble), Acid Insoluble Residue, Ash (Acid Insoluble),
As P10 plus protein-corrected lignin, water-soluble sugars, uronic acids, acetyl content and starch.
Glucuronic Acid, Galacturonic Acid, Mannuronic Acid, Guluronic Acid, 4-O-Methyl-D-Glucuronic Acid, Iduronic Acid,
Total Sugars in Enzyme Hydrolysate, Glucose in Enzyme Hydrolysate, Xylose in Enzyme Hydrolysate, Arabinose in Enzyme Hydrolysate, Mannose in Enzyme Hydrolysate, Galactose in Enzyme Hydrolysate, Rhamnose in Enzyme Hydrolysate, Cellobiose in Enzyme Hydrolysate, Enzymatic Hydrolysis Kinetics, Cellulose Conversion Yield, Xylan Conversion Yield, Combined Sugar Yield, Cellulose Conversion Rate, Xylan Conversion Rate,
As P121 plus comparisons with data from the non-pretreated original sample, including: Increase in Cellulose Accessibility after Pre-Treatment, Percent Increase in Cellulose Conversion Efficiency, Percent Increase in Cellulose Conversion Rate.
As P9 but on the solid residue after enzymatic hydrolysis.
Formic Acid, Acetic Acid, Levulinic Acid, Furfural, Hydroxymethylfurfural,
Includes all hydrolysate sugars and kinetics in P121 and: Cellulose Conversion Yield, Cellulose Conversion Rate
Includes all hydrolysate sugars and kinetics in P121 and: Xylan Conversion Yield, Xylan Conversion Rate
Total Sugars in Enzyme Hydrolysate, Glucose in Enzyme Hydrolysate, Maltose in Enzyme Hydrolysate, a-Amylase Hydrolysis Kinetics, Glucoamylase Hydrolysis Kinetics,
Glucose, Xylose, Fructose, Sucrose, Mannose, Arabinose, Galactose, Rhamnose, Xylitol, Sorbitol, Trehalose, Mannitol, Arabinitol, Glycerol, Raffinose,
Levulinic Acid, Formic Acid, Hydroxymethylfurfural, Furfural, Acetic Acid, gamma-Valerolactone,
Xylobiose, Xylotriose, Arabinobiose, Arabinotriose,
Maltose, Maltotriose, Maltotetraose, Maltopentaose, Maltohexaose, Maltoheptaose, Maltooctaose,
Glucuronic Acid, Galacturonic Acid, Mannuronic Acid, Guluronic Acid, 4-O-Methyl-D-Glucuronic Acid, Iduronic Acid,
Gibberellic Acid, Indole-3-acetic acid, Indole-2-acetic acid, Indole-3-propionic acid, Indole-3-butyric acid, 6-Benzylaminopurine, Kinetin riboside, Abscisic acid, Salicylic acid,
beta-Carotene, Ergocalciferol (Vitamin D2), Alpha-tocopherol (vitamin E), Phylloquinone (Vitamin K1),
Thiamine (Vitamin B1), Riboflavin (Vitamin B2), Niacin (Vitamin B3), Niacinamide (vitamin B3), Pantothenic Acid (Vitamin B5), Pyridoxine (Vitamin B6), Folate (Vitamin B9), Cobalamin (Vitamin B12), Ascorbic Acid (Vitamin C),
Fucose, Mannitol, Glucose, Xylose, Mannose, Arabinose, Galactose, Rhamnose, Total Sugars, Glucuronic Acid, Galacturonic Acid, Mannuronic Acid, Guluronic Acid, Iduronic Acid,
Alanine, Arginine, Aspartic Acid, Asparagine, Cystine, Glutamic Acid, Glutamine, Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Proline, Serine, Threonine, Tryptophan, Tyrosine, Valine,
Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium,
Arachidic Acid, Behenic Acid, Decanoic Acid, Erucic Acid, Lauric Acid, Linoleic Acid, Linolenic Acid, Myristic Acid, Caprylic Acid, Oleic Acid, Palmitic Acid, Palmitoleic Acid, Stearic Acid, Lignoceric Acid,
Fucoxanthin, Astaxanthin, Chlorophyll-c, Chlorophyll-a, Chlorophyll-b, Lutein, beta-Carotene, Neoxanthin, Antheraxanthin, Violaxanthin,
Gibberellic Acid, Indole-3-acetic acid, Indole-2-acetic acid, Indole-3-propionic acid, Indole-3-butyric acid, 6-Benzylaminopurine, Kinetin riboside, Abscisic acid, Salicylic acid,
beta-Carotene, Ergocalciferol (Vitamin D2), Alpha-tocopherol (vitamin E), Phylloquinone (Vitamin K1),
Thiamine (Vitamin B1), Riboflavin (Vitamin B2), Niacin (Vitamin B3), Niacinamide (vitamin B3), Pantothenic Acid (Vitamin B5), Pyridoxine (Vitamin B6), Folate (Vitamin B9), Cobalamin (Vitamin B12), Ascorbic Acid (Vitamin C),
Chlorophyll-a, Chlorophyll-b, Lutein, beta-Carotene, Neoxanthin, Astaxanthin, Zeaxanthin, Antheraxanthin, Violaxanthin,
Biomethane Potential (BMP), Total Biogas Volume, Total Solids, Volatile Solids, pH, Biogas Methane Content, Biogas Carbon Dioxide Content, Biogas Oxygen Content, Biogas Hydrogen Sulphide Content, Biogas Ammonia Content,
Total Solids, Volatile Solids, pH, Chemical Oxygen Demand (COD),
Residual Biogas Potential (RBP), Total Biogas Volume, Total Solids, Volatile Solids, pH, Biogas Methane Content, Biogas Carbon Dioxide Content, Biogas Oxygen Content, Biogas Hydrogen Sulphide Content, Biogas Ammonia Content,
Acetic Acid, Lactic Acid, Propionic Acid, Butyric Acid, Isobutyric Acid, Valeric Acid, Isovaleric Acid,
Levoglucosan, Cellobiosan, Mannosan, Galactosan, Glucose, Xylose, Mannose, Arabinose, Galactose, Rhamnose, Fucose, Sucrose, Cellobiose, Total Sugars,
31 constituents including Phenol, Furfural, Syringol, and Vanillin
Specific Surface Area (Nitrogen Gas Adsorption), BET Isotherm (5 Point Using Nitrogen),
Specific Surface Area (Nitrogen Gas Adsorption), BET Isotherm (20 Point Using Nitrogen), Pore Volume (Using Nitrogen), Pore Size Distribution (Using Nitrogen), Average Pore Width (Using Nitrogen),
Specific Surface Area (Nitrogen Gas Adsorption), BET Isotherm (40 Point Using Nitrogen), Pore Volume (Using Nitrogen), Pore Size Distribution (Using Nitrogen), Average Pore Width (Using Nitrogen),
Gross Calorific Value, Net Calorific Value, Ash, Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen,
Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium,
Antimony, Arsenic, Cadmium, Chromium, Cobalt, Copper, Lead, Manganese, Mercury, Molybdenum, Nickel, Vanadium, Zinc,
Ash Shrinkage Starting Temperature (Reducing), Ash Deformation Temperature (Reducing), Ash Hemisphere Temperature (Reducing), Ash Flow Temperature (Reducing),
Moisture, Ash Content (815C), Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen, Chlorine, Volatile Matter, Fixed Carbon, Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium, Gross Calorific Value, Net Calorific Value, Ash Shrinkage Starting Temperature (Reducing), Ash Deformation Temperature (Reducing), Ash Hemisphere Temperature (Reducing), Ash Flow Temperature (Reducing),
As P393 plus inorganic carbon, organic carbon, TGA (under nitrogen and air), and inherent moisture
Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium,
Antimony, Arsenic, Cadmium, Chromium, Cobalt, Copper, Lead, Manganese, Mercury, Molybdenum, Nickel, Vanadium, Zinc,
Acenaphthene, Acenaphthylene, Anthracene, Benz[a]anthracene, Benzo[b]fluoranthene, Benzo[k]fluoranthene, Benzo[ghi]perylene, Benzo[a]pyrene, Chrysene, Dibenz[a,h]anthracene, Fluoranthene, Fluorene, Indeno[1,2,3-cd]pyrene, 1-Methylnaphthalene, 2-Methylnaphthalene, Naphthalene, Phenanthrene, Pyrene,
Time to Germination, Mean Shoot Length (Week 1), Mean Shoot Length (Week 2), Mean Shoot Length (Week 3), Mean Shoot Length (Week 4), Shoot Weight (Week 4), Mean Root Length (Week 4), Root Weight (Week 4),
As Deluxe package plus P383, SEM Imaging (P387) and Plant Growth Trials (P388)
Includes everything from P391 (Physical Properties Ultimate), P394 (Thermal Properties Ultimate), and P397 (Soil Amendment Ultimate)
Gross Calorific Value, Net Calorific Value, Ash, Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen,
Aluminium, Calcium, Iron, Magnesium, Phosphorus, Potassium, Silicon, Sodium, Titanium,
Antimony, Arsenic, Cadmium, Chromium, Cobalt, Copper, Lead, Manganese, Mercury, Molybdenum, Nickel, Vanadium, Zinc,
Volatile Matter, Fixed Carbon, Moisture, Ash, Carbon, Hydrogen, Nitrogen, Sulphur, Oxygen, Gross Calorific Value, Net Calorific Value, Chlorine,
Ash Shrinkage Starting Temperature (Oxidising), Ash Deformation Temperature (Oxidising), Ash Hemisphere Temperature (Oxidising), Ash Flow Temperature (Oxidising),
Celignis is a Partner in 3 Successful Proposals for EU Funding
We are pleased to announce that three of the proposals involving Celignis, submitted to the CBE-JU programme for funding collaborative biomass research in Europe, were successful. These projects will provide an additional funding of €1.5m to Celignis and build on our achievements in other CBE and EU projects. In particular, the projects are all at enhanced TRLs (6/7) and will use our existing Celignis Bioprocess infrastructure and will also fund further development of our bioprocessing capacities and the Bioprocess Development Services we offer our clients.
Details on the funded projects are provided below:
BIONEER - This project was funded under CBE-JU topic IA-06 and focuses on the TRL 6/7 production of biobased platform chemicals. Celignis's activities in the project focus on scaling up the work undertaken in our ongoing
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The 2024 North American Biochar Conference will take place in Sacramento, California, on Feb 12-15
On Feb 12-15 we'll be exhibiting at the 2024 North American Biochar Conference, taking place at the SAFE Credit Union Convention Centre in Sacramento, California.
We're looking forward to interacting with the 1000+ expected attendees, outlining our extensive range of analytical and application testing services for biochar.
Celignis CIO Lalitha Gottumukkala will also be a member of the expert panel focused on developing improved laboratory methods for biochar characterisation.
Click here to register for the event.
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This Networking Event Will Involve Discussions on Collaborations for Proposals to the 2024 CBE-JU Topics
The Circular Bioeconomy Europe Joint Undertaking (CBE-JU) is an organisation that funds biomass research in Europe at various Technology Readiness Levels (TRLs). Since 2016 Celignis has been an active participant in a number of projects funded by the CBE-JU.
The Biobased Industries Consortium (BIC) is the steering committee that helps to steer the focus of research for the CBE-JU programme. In 2023 Celignis joined the BIC as a Full Industry Member and participated in several proposals submitted for different research topics in the CBE-JU's 2023 Work Programme.
On Feb 8th Celignis's Dan Hayes, Lalitha Gottumukkala, and Oscar Bedzo will be attending a BIC networking event in Brussels where we will discuss potential collaborations in the research programme topics recently announced for 2024.
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This position will involve working closely with senior management, fostering existing and new client relationships.
Situated in Limerick, Ireland, Celignis currently operates at two centres, Celignis Analytical and Celignis Bioprocess, actively engaging in a variety of private and public bioeconomy projects. As we continue to expand, we're looking to strengthen our team of 14 with a Business Administration and Client Relationship Manager who can bring a blend of enthusiasm and expertise.
This position will involve working closely with senior management, fostering existing and new client relationships, and ensuring successful delivery of our services, playing a key role in our ongoing growth and success.
Click here for more details about the position.
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The event takes place on May 3rd at Carrick-on-Shannon
We are pleased to announce that, on May 3rd, Celignis will be presenting and exhibiting at the National Biochar and Carbon Products Conference 2023, which is taking place in Carrick-on-Shannon in County Leitrm, Ireland.
This conference is being organised under the auspices of the Interreg Northwest Europe-funded THREE C Project, entitled 'Creating and sustaining Charcoal value chains to promote a Circular Carbon economy in NWE Europe'.
The conference will highlight both Irish stakeholders who are currently working in the biochar and carbon products sector, but also partners from the THREE C project (covering Netherlands, Luxembourg, Germany, Belgium, France and Wales, as well as Ireland) who have interesting stories and products to share.
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