Investigating the thermochemical conversion of biomass in a downdraft gasifier with a volatile break-up approach

Abstract

An affordable, reliable and clean energy supply is the major challenge facing by the modern world. Biomass energy is playing a promising role to that, but gasification technology able to convert biomass efficiently to valuable gases for power and heat generation is a vital need. The aim of this study is to develop a robust computational fluid dynamics (CFD) model to better understand the gasification thermochemical processes of a selected biomass (rubber wood) in a 20 kW downdraft gasifier, which includes all the four zones, drying, pyrolysis, oxidation and reduction. A step-by-step approach is proposed to evaluate the composition of different species as a result of volatile break-up during gasification. Effect of the equivalence ratio on the synthesis gas composition is studied with results validated against a kinetic model. Further, in this study temperature profile in the gasifier at different equivalence ratio (ER) has been studied.