Investigation of biomass gasification simulation using air, steam and oxygen as gasifying agent

Abstract

The syngas produced from gasification process is used for many applications: the selection of fuel, gasifying medium, and operating condition has major influence on the final gas composition. In the present work, rice husk air gasification, rice husk steam gasification, sawdust air gasification and sawdust oxygen gasification simulation were carried out by non-stoichiometric equilibrium model based on Gibbs free energy minimization using FACTSAGE 6.3 software. The investigation is carried out to study the effect of operating conditions on biomass gasification. In rice husk air gasification, increase in temperature enhances H2 value at equivalence ratio ? = 0.25, at other ? values after reaching optimum value H2 formation decreases. In sawdust oxygen gasification, increase in ? value enhances CO2 formation for all temperatures and increase in temperature reduces CO2 formation for all ? value. Increase in equivalence ratio for all the temperatures decreases the combustible gases formation due to the oxidation reactions. Gas compositions were compared to study the effect of fuel quality and gasifying medium on the gasification process. Rice husk air gasification has 5.85% higher CO formation than sawdust air gasification at 800?C and ? = 0.45. The maximum difference of 13.8% was observed for H2 content at 700?C and ? = 0.45 between sawdust air and oxygen gasification. Gas heating value and gasification efficiency were determined for the biomass gasification processes.