Thermodynamic optimization of biomass gasifier for hydrogen production

摘要

A thermodynamic equilibrium model was used to predict the chemical composition of the products of biomass gasification. The effects of temperature, pressure, steam biomass ratio (SBR) and equivalence ratio (ER) on the equilibrium hydrogen yield were studied. Gibbs energy minimization approach was used to determine the product gas composition. Wood (designated by CH_(1.5)O_(0.7)) was used as the model biomass compound and Stanjan (v 3.93L) software was used. Gasifier, the most critical component of any biomass gasification system, was modeled as an equilibrium reactor and the energy consumption and thermodynamic efficiency were determined. A first law analysis of the gasifier showed that the optimum conditions for hydrogen production occurred at a gasification temperature of 1000K, SBR of 3, ER of 0.1. Finally, equilibrium calculations were compared with experimental data from literature which showed that for high gas residence times and high gasification temperatures there is a close match of equilibrium results with experimental ones.