Influence of biomass materials and gas flow rate on downdraft gasifier performance

Abstract

In this article, the performance of a 20 kWe open top downdraft biomass gasifier has been modeled using EQB computer code. EQB program, consists of six modules (i.e., fluid flow, heat transfer, drying, pyrolysis, and oxidation and reduction reactions), has been used to describe physical and chemical processes of downdraft biomass gasifier. A brief description of EQB, its strength and limitations are also highlighted. Model predictions fitted well with measurements. The influence of gas flow rate and type of biomass materials (i.e., soft-wood, ordinary-wood and hard-wood) on dry gas composition, calorific value, conversion efficiency, temperature profile, and gasifier power output has been investigated. Although, results for gasifier operated on different biomass materials give relatively low fluctuations, even though, hardwood is identified better class of wood material.