• Use of Biochar
    For Carbon Sequestration
    Relevant Tests at Celignis


Carbon sequestration refers to the capture and long-term storage of atmospheric carbon dioxide (CO2), a major greenhouse gas contributing to global warming and climate change.

In recent decades the production and use of biochar has been considered as a strategy for reducing the levels of carbon dioxide in the atmosphere. This can potentially be achieved in direct and indirect ways.

The main reason that biochar is considered to be a direct approach for carbon sequestration is that the carbon in biochar is mainly composed of recalcitrant carbon, which is resistant to degradation by microorganisms and can persist in the environment for hundreds or even thousands of years. By converting biomass into biochar, the carbon in the biomass is stabilized and locked away, preventing it from being rapidly released back into the atmosphere as CO2 which would otherwise be the case as the biomass feedstock is consumed or decomposes. Hence, providing that the biomass that is used to produce the biochar is replenished, the net effect of growing biomass for the production of biochar is that atmospheric CO2 is sequestered in the soil in a stable form.

Biochar can potentially indirectly reduce anthropogenic greenhouse gas emissions by improving soil quality through its enhancement of nutrient and water retention. This results in a reduction in the acidity of the soil and provides a more favourable habitat for beneficial soil microorganisms. These improvements can increase agricultural productivity and potentially reduce the need for synthetic fertilizers, a source of greenhouse gas emissions.

Additionally, biochar production can utilize various types of waste biomass, including agricultural residues, forestry waste, and urban green waste, so diverting these materials from landfills or open burning, both of which can produce greenhouse gases.

Effects of Pyrolysis Conditions on Biochar Carbon Sequestration Potential


Pyrolysis temperature is a critical factor that influences the carbon sequestration potential of biochar. Higher pyrolysis temperatures typically lead to the formation of biochars with higher carbon contents and greater recalcitrance, as more volatile compounds are released, and the remaining carbon structure becomes more condensed and stable. However, very high temperatures can result in excessive carbon loss through the formation of gaseous products, reducing the carbon sequestration potential of the biochar.

Heating Rate

The heating rate, or the rate at which the biomass is heated during pyrolysis, can also influence the carbon sequestration potential of biochar. Rapid heating rates can lead to the production of biochars with higher carbon contents. However, excessively fast heating rates can cause uneven pyrolysis and the formation of biochars with lower carbon sequestration potential.

Residence Time

Longer residence times can result in more complete pyrolysis, potentially leading to the formation of biochars with higher carbon contents and greater stability. However, excessive residence times may lead to the production of biochars with lower carbon sequestration potential due to an increased amount of the biomass being volatilised.

Choice of Feedstock

Different feedstocks have varying carbon contents, which can affect the amount of carbon sequestered in the resulting biochar. Generally, feedstocks with higher carbon contents, such as woody biomass, will produce biochars with greater carbon sequestration potential than those with lower carbon content, such as herbaceous or aquatic plants.

Celignis Tests to Assess Carbon Sequestration Potential of Biochar

Proximate and Elemental Analysis

We can analyse biochar for its fixed carbon and volatile matter contents. Typically, biochars with higher fixed carbon contents tend to be more stable over longer periods of time and less likely to be degraded and return CO2 to the atmosphere.

We can also determine the carbon content of biochar using Dumas analysis and can differentiate between organic carbon and inorganic carbon. A higher organic carbon content indicates a greater potential for carbon sequestration.

Stability and Decomposition Tests

These tests assess the resistance of biochar to microbial degradation and its potential longevity in the environment. Stability tests may involve monitoring CO2 emissions from biochar-amended soil over time or using techniques such as the incubation method, where biochar is mixed with soil and incubated under controlled conditions to measure CO2 emissions.

Carbon Sequestration Efficiency

This metric compares the amount of carbon content sequestered in the biochar to the total carbon content in the original biomass feedstock. It can be used to evaluate the effectiveness of different feedstocks and pyrolysis conditions in producing biochar with high carbon sequestration potential.

Additional Information on Biochar Carbon Sequestration Potential

Feel free to get in touch with us if you have any questions about our analytical services to evaluate thje carbon sequestration potential of biochar. Relevant members of the Celignis biochar team will be happy to assist. Those team members with the most experience with undertaking these tests and interpreting the resulting data are listed below.

Sajna KV

Bioanalysis Developer


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.

Lalitha Gottumukkala

Chief Innovation Officer


A serial innovator managing multiple projects. Has particular expertise related to the upgrading of biochar and on the assessment of its impact on plant productivity and soil health.

Other Celignis Tests and Services for Biochar

Global Recognition as Biomass and Biochar Experts

Celignis provides valued services to over 1000 clients. We understand how the focus of biochar projects can differ between countries and have advised a global network of clients. We also have customs-exemptions for samples sent to us allowing us to quickly get to work no matter where our clients are based.

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Feedstock Evaluation

Our analysis packages can screen biochar feedstocks. We can estimate biochar yield and quality using feedstock chemical composition and can estimate biochar composition using the ultimate and major/minor elements analyses of the feedstock. With TGA analysis we can also monitor feedstock behaviour under pyrolysis conditions.

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Biochar Production

We can produce biochar samples from your feedstocks using a wide range of temperatures, heating rates, and residence times. We can formulate a Design of Experiments (DoE) to study the effects of varying process parameters on biochar yield and quality and can optimise these outputs according to your desired biochar market applications.

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Biochar Analysis

We have an extensive array of analysis packages to evaluate the suitability of biochar for a range of applications. These analyses cover properties relevant to combustion, soil amendment, feed, and biomaterials. Our reports compare the results against internationally-recognised limits for using the biochar in specific end-products.

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Biochar Combustion Properties

Biochar can be a superior fuel versus virgin biomass due to its greater carbon content and energy density. We offer a wide array of analysis packages to fully evaluate biochar as a fuel. For example, we can determine both organic and inorganic carbon and can monitor the behaviour of the biochar ash over wide temperature ranges.

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Soil Amendment & Plant Growth Trials

We can test biochar for several properties (e.g. water holding capacity, electrical conductivity etc.) relevant to its use in soil amendment. We can also grow plants in biochar-amended soils and assess the impacts of this approach on germination, plant growth, plant health, and soil biology.

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Analysis of PAHs in Biochar

Polycyclic aromatic hydrocarbons can be formed during the pyrolysis of biomass and accumulate in biochar, leading to potential risks to the environment. We can accurately quantify a range of different PAHs and determine if their concentrations exceed regulatory limits. We can also develop strategies to reduce the amount of PAHs in biochar.

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Surface Area and Porosity of Biochar

The suitable markets for a biochar are often greatly dependent on its surface area and pore size-distrubtion. We provide detailed reports on biochar surface area and porosity and can provide guidance on the implications of the results. We can also work on strategies to increase the surface area and modify the pore-size distribution of biochar.

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Thermogravimetric Analysis of Biochar

TGA is a powerful analytical technique for the study of biochars because it allows us to examine the thermal stability of the material as a function of temperature. The thermal stability of biochars is an important factor to consider when evaluating their potential use as a soil amendment or for carbon sequestration.

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Biochar Upgrading

There are several different methods (covering physical, chemical and biologial routes) by which we can upgrade your biochar in order to increase its value and make it more suitable for the desired market applications. We are able to fully characterise the changes in physicochemical properties associated with upgrading.

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Technoeconomic Analyses of Biochar Projects

Our TEA experts work with you to evaluate the economic prospects of your biochar facility, considering various scale, technology, and feedstock options. We apply accurate costing models to determine CAPEX/OPEX of simulated and pilot scale processes which are then used to determine key economic indicators (e.g. IRR, NPV).

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Research Project Collaborations

Celignis is active in a number of important research projects focused on biomass valorisation. Biochar is a key component in some of these ongoing projects as well as in several prior projects. We are open to participating in future collaborative research projects where our extensive infrastructure and expertise in biochar can be leveraged.

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