The Biochar Summit showed biochar’s potential being unlocked – but what about the global south?

The carbon dioxide budget is running out, and it is more urgent than ever to mitigate and remove emissions in order to keep global temperature rise below 1.5 °C and well below 2 °C. While carbon capture technologies are often discussed as a means to eliminate emissions, they seem distant, complex, and costly. However, an alternative approach is gaining attention, particularly in the agricultural sector. Biochar, like a phoenix rising from the ashes of forgotten indigenous knowledge, is being promoted as a technology with numerous benefits, including soil improvement, energy production, and carbon dioxide emission reduction.

The growing significance of biochar has led to the organization of the world’s first Biochar Summit, a conference held from June 12th to 15th (2023) in Helsingborg, Sweden. Participants had the opportunity to interact with pyrolysis units used for biochar production during the study visits. They also engaged in workshops focused on biochar’s applications in soil and construction materials and got hands-on experience in the development of simple business models for biochar production and commercialization. The presentations covered biochar’s interaction with soil, carbon dioxide removal (CDR) potential, policy implications, alternative uses in construction, energy production, efficient pyrolysis equipment, and future possibilities for reducing carbon emissions.

Experts in soil, sustainability, biochar, energy, policy, and entrepreneurship met for the first time. This diversity contributed to a content-rich program centred around biochar as the main topic. However, most participants represented global North projects, which was reflected in the limited number of presentations or posters addressing biochar production and use in the global South.

Calling for access to better biochar technology for the global South

Unlike other CDR methods, biochar provides an opportunity to repurpose agricultural biomass residues instead of allowing them to decompose and release carbon dioxide into the atmosphere.
Countries closer to the Earth’s equator, with favourable conditions for year-round agriculture due to constant sunlight and humid weather, have great potential for biochar production using residual biomass from agricultural activities. Biochar mitigates the carbon emissions from this biomass and, if incorporated into agricultural soil with low-quality, can provide positive crop growth conditions. Knowledge and technology transfer are key to unlocking the biochar potential in tropical countries.
Ensuring the use of the best available technologies for biochar production is crucial in all regions. While cheaper artisanal equipment is commonly used in lower- and middle-income countries due to cost constraints, these artisanal units are often open to the air and do not recirculate production process gases. As a result, particulates are emitted into the atmosphere, posing risks to both health and the environment.
Biochar certifications in wealthier regions require technologies that utilize gases and liquid products produced during biochar production, which are more environmentally friendly. However, some certification schemes allow for artisanal production in lower- and middle-income contexts, potentially hindering the implementation of biochar production technologies that minimize negative environmental effects in regions with significant residual biomass potential. Promoting and enabling the same technological conditions for biochar production in all nations, including the global South is essential.

Small but mighty – re-purposing biomass residues

Biochar is the solid carbon-rich product of biomass transformation through pyrolysis in an oxygen-free atmosphere. It is recommended to only use residual biomass for biochar production, such as biomass residues from urban gardening and agricultural harvesting. Alternatives for utilising biochar as a CDR include use in agricultural soils or in products (e.g., construction materials). Interestingly, the earliest records of biochar use in agriculture date back to pre-Columbian times in the Amazon region, in soils with a dark colour. These soils are known as “terra preta do indio” or Amazonian Dark Earths.
The yield of biochar is influenced by the type of biomass used and the temperature of pyrolysis. When biomass is pyrolyzed, it results in three co-products: biochar, biogas, and bio-oil. The produced biochar can be further re-integrated back into the soil, and the biogas and bio-oil can be used as energy sources (e.g., as a heating source). Pyrolysis at lower temperatures, ranging between 350 °C to 450 °C, yields a larger percentage share of biochar.
In agricultural applications, the permanence of the carbon stored in biochar depends on the soil temperature where the biochar is employed. While carbon is stored for longer in colder soils, biochar can still benefit crop growth in fields with degraded soil. Biochar can ameliorate degraded soils, improve soil water retention and create enhanced conditions for crop growth in previously degraded soils while mitigating carbon emissions from residual biomass feedstock.

Opening horizons

Hope and tech optimism marked the world’s first Biochar Summit. Scientists, technology and carbon credit providers, and biochar producers, sellers, and users, attested to the benefits this carbon-rich material has. While always keeping in mind biochar’s potential for carbon dioxide removal, the conference served as a platform for sharing knowledge-through diverse case studies showcasing biochar’s applications in agriculture. Additionally, the energy production potential associated with biomass pyrolysis was highlighted. The Summit also featured presentations from technology providers offering pyrolysis units that effectively utilize pyrolysis gases, which are already being used in Europe.
The Summit evidenced that the expertise, technology, and experience necessary for biochar production and utilization are available. This presents an opportunity to foster the development of best practices for biochar production and use, particularly in the global South.

Although there was relatively low participation from individuals representing the global South, whether due to biochar being less well-known as it is in Europe and North America or the associated expenses of attending the conference, it became clear that biochar has the potential to offer agricultural and environmental advantages worldwide.

To bridge this gap, efforts can be made to provide access to appropriate technology and raise awareness about the potential use of biomass residues. Sharing knowledge on their production and utilization can also be helpful. While some startups are making strides in biochar production in tropical countries, progress has been gradual, often utilizing artisanal technology that may not be the best choice.

Written by Eileen Torres, Research Associate at SEI Headquarters.