Operational assessment of downdraft gasification of agricultural residues from cassava cultivation

Cassava is a widely grown crop in Northeastern Brazil that generates agricultural residues during its cultivation. Through gasification, which is a widely conversion process used for woody biomass, there is a potential to make better use of the available biomass energy in cassava stalks. This study provides practical exploration of cassava residues gasification by implementing a mathematical model to analyze and optimize the process under realistic conditions and equipaments. Lab-scale experiments were conducted to support and validate outcomes. For an equivalence ratio of 0.35 the syngas yield is 2.22 Nm 3 /kg with a lower heat value of 3.917 MJ/Nm 3 and a cold gas efficiency of 80%. Additionally, the potential syngas yield from cassava in Northeastern Brazil was estimated, potential to generate 5.81 billion Nm 3 per year of syngas from 2.61 million tons of cassava residue produced annually. • The model analyzed cassava residue gasification, showing its clean energy potential. • Higher ER increases syngas yield and decreases LHV, while higher MC reduces both. • Tar yield decreases with ER and increases with MC, while char yield rises with both. • Cassava in Northeastern Brazil could produce 5.81 billion Nm 3 of syngas annually.