Design and Testing of Biochar Stoves

Abstract

Biochar is a solid material obtained from the carbonization of biomass. Biochar is used on agricultural lands as a soil amendment to improve the fertility of the soils. Currently the most common method of producing biochar is through biochar stoves. There are two basic stove operations in the production of biochar. The first type of stove produces biochar by direct combustion of biomass. Here biomass is burnt inside a chamber in an oxygen limited environment. The resulting residue is the bio-char. The second type involves burning the biomass in one chamber and housing the biomass to be charred in the annular portion of an outer chamber. Heat is transferred from the burning fuel on the inner chamber to the material to be charred in the outer chamber. While the process of biochar production in these stoves is known, the basic principles of the stove design are not readily available. The design methodology for both the types was developed from first principles. Prototypes of both types were constructed based on the design developed and tested. The paper lists the basic principles in the design of biochar stoves and the test results.