Waste management is an environmental issue that is faced by many countries across Africa. A large number of farmers burn crop residues such as corn stalks and rice husks in the open fields. This open field burning not only releases large amounts of carbon dioxide and particulate matter into the air and affects people’s health, it also destroys essential soil nutrients and burns vital soil microorganisms. Residuals such as these have the potential to create long-term land degradation and reduce crop yields. Carbonization of biomass in a professionally designed and operated plant offers a healthy alternative to these destructive practices. Through the controlled heating of organic materials, a biomass carbonization plant produces valuable by-products.
When choosing a biomass carbonization plant for your project, investors must first look at some of the key technical features that will ensure that the best model is chosen to process peanut shells, wood pellets or palm kernel for your specific requirements. This will be based on the properties of the biomass including moisture and density. It is important that the chosen carbonizer has the ability to carbonize continuously, to maintain the best efficiency and highest output. In the African market, it is equally important that the carbonizer is durable for outdoor use and should have the most advanced thermal insulation design with special corrosion resistant material selection. This ensures that as much energy as possible is not wasted during the whole heating process. Finally, a great design is also ‘modular’ and easy to transport and assemble in remote rural agricultural areas.
A biomass carbonization plant processes a wide variety of organic waste materials to produce biochar. This is achieved through a process of thermo-chemical decomposition in an oxygen restricted environment at high temperatures. The end product is biochar, a carbon based solid that has large pores within its structure retaining water and preventing loss of water from soil. Biochar also acts as a medium to carry fertilizers and stop them leaching out during heavy down pours of rain. Farmers can turn their waste problem in to an agricultural asset by building a biomass carbonization plant. The product quality is influenced by the temperatures achieved within the reactor.
Operational sustainability of biomass carbonization plants comes from generating multiple streams of revenue for the operator. Some of the product is sold as high quality biochar to large commercial or cooperative farm operations. The remainder of the product is converted into a highly combustible gas during carbonization, which is captured, cleaned and recirculated back into the reactor for further heating. This stream of gas can also be used as fuel for gas generators to produce electricity to power the operation of the plant, especially after the initial load of feedstock has been converted. This self-sufficiency unlocks high return on investment for such plants which can operate as small energy hubs in rural areas.
The environmental impact of biomass carbonization is not limited to local level but extends to the global challenge of meeting environmental targets for reducing atmospheric carbon concentration. The biochar that is produced during the carbonization of biomass is a permanent reservoir of carbon. It remains in the environment for hundreds or even thousands of years. In Africa, where much land has been degraded to the point where it is highly acidic and has very low fertility, the addition of biochar to the soil will greatly increase the cation exchange capacity of the earth. This means that nutrients are more available to plant roots, and plants have the potential to grow much stronger and healthier. Additionally, the rehabilitation of these degraded areas of land represents one of the major mitigation initiatives to prevent desertification and land degradation. Turning dying farmland back into a productive resource supports sustainable agriculture practices that save eco-systems and environmental services for future generations. The long term carbon sequestration from carbonization plant operations can also provide the basis for carbon credit sale on the international carbon markets, thus generating an income stream for rural operators and communities.
Developing a biomass carbonization plant is a strategic contribution to the transition to a “circular economy”. In fact, it is considered an innovative “turnkey business” that offers great potential for local governments and private investors. The opportunity to obtain substantial agricultural benefits, by moving away from the use of chemical fertilizers and fossil fuels, creates new income and employment opportunities and boosts the local economy. The carbonization of biomass represents a much more sophisticated process than simply burning waste. It leads to the production of premium activated carbon, which replaces chemicals in industrial processes and also serves as a high-quality bio-fertilizer for the agricultural sector, actually increasing the yield and quality of crops. This approach transforms a major agricultural liability into a valuable opportunity for a healthier environment and a more competitive food system. As more and more regions develop their own biomass carbonization plant, Africa will be closer to reaching its sustainable development goals.
Converting agricultural waste into useful biochar with the help of an African biomass carbonization plant leads to a plethora of sustainable benefits for the region including energy production and healthy soil.
