Biochar: An innovative way to remove carbon

Climate change poses an ever-increasing threat and requires swift and decisive action to reduce carbon emissions. In addition to emissions reduction, the creation of carbon sinks has become essential to effectively combat the climate crisis. Among the various solutions, biochar (also called plant charcoal or biochar) has emerged as a rapidly growing carbon removal technology. This article explores the role of biochar in removing carbon from the atmosphere and is also aimed at sustainability and ESG leaders worldwide.

Biochar production and its by-products

Biochar, a carbon-rich material, is typically produced by pyrolysis of biomass without oxygen. Pyrolysis involves heating biomass, such as wood, agricultural residues, or organic waste, to high temperatures (typically 500–700°C). During pyrolysis, volatile compounds are released, primarily carbon monoxide (CO) and hydrogen (H₂), as well as smaller amounts of carbon dioxide (CO₂), methane (CH4), and water vapor (H₂O). When not used for on-site heat generation, the pyrolysis gas can be refined into bio-oil, a renewable energy source and precursor to various chemicals.

The biochar production process is versatile and can take place at various scales, from small cookstoves to large industrial facilities. Modern pyrolysis plants efficiently capture and combust the released gases, ensuring that biochar production does not cause air pollution or greenhouse gas emissions. Furthermore, the heat generated during the process can be used as renewable energy, making biochar a sustainable option for carbon removal.

Characterization of biochar-soil dynamics

The quality of biochar is determined by various physical properties: pH, volatile compound content, ash content, bulk density, pore volume, and specific surface area. The properties and nutrient content of biochar depend on the feedstock and production parameters. Researchers have found that the temperature of the pyrolysis process plays a crucial role in optimizing the soil properties of biochar. Temperatures of approximately 500 °C produce biochar with an ideal balance between carbon recovery, cation exchange capacity (CEC), pH, and surface area, thus maximizing its effectiveness as a soil amendment.

Certification of biochar carbon credits

Growing recognition of biochar's potential for carbon removal has led to the establishment of biochar carbon credit certification schemes. These schemes quantify and verify the carbon sequestration benefits of biochar production. Carbon credits are generated based on the amount of carbon dioxide that biochar permanently (100 years or more) sequesters in the soil, effectively removing it from the atmosphere.

Certification ensures accurate accounting of carbon credits and compliance with strict standards. Third-party verification of biochar production processes, carbon sequestration calculations, and the permanence of carbon storage is essential. Certification bodies such as Puro.Earth or the European Biochar Certificate (EBC) guarantee rigorous auditing and verification, prevent double counting, and ensure the credibility of carbon removal claims.

The European Biochar Certificate (EBC, website) ensures sustainable biochar production and prevents risks to health and the environment. It provides customers with a reliable quality standard and helps producers demonstrate compliance with recognized quality criteria. As a voluntary industry standard, the EBC sets a precedent for the expansion of biochar use in Europe and is in line with research and development activities in this field.

Puro.earth (website) is another certification body. This company is leading the way in ensuring the integrity of carbon markets through its Puro Standard, the first standard for carbon removal by engineering methods in the voluntary carbon market. This high-quality standard encompasses various carbon removal methods, including biochar, carbonized materials, geologically stored carbon, enhanced rock weathering, and the burial of woody biomass, all of which align with the IPCC's definition of carbon removal. The cornerstone of Puro.earth's approach is the CO₂ Removal Certificate (CORC), which represents one ton of CO₂ removed using Puro Standard methods.

Conclusion

Biochar has proven to be a powerful method for removing carbon from the atmosphere. Its application to improve soil health and promote regenerative agriculture makes it an attractive option for businesses and sustainability leaders worldwide. With the support of carbon removal credits and certification standards such as Puro.Earth and the European Biochar Certificate, large-scale biochar production is becoming financially viable and offering hope in the global fight against climate change. As companies adopt sustainable practices, biochar will play a vital role in achieving net zero and securing a greener future for our planet.

Here is a flyer about biochar as a project type.