Optimum Equivalence Ratio of Biomass Gasification Process Based on Thermodynamic Equilibrium Model

This study provides the optimum equivalence ratio of biomass gasification process based on thermodynamic equilibrium model. There are two cases of chemical equilibrium in a gasification process. The first being with excess carbon present in the gasification process while the second one possess excess gasifying agent with all the carbon completely gasified. The simulation results clearly show that under the certain conditions, there must exist a case between these two cases where the carbon is completely gasified without any excess gasifying agent or carbon. This point has been determined from the cross over point between CO2 and CO. Moreover, the results show that at higher gasifying agent temperatures the trend of CO increases more sharply than that at lower gasifying agent temperatures and vice versa for CO2. The optimum equivalence ratio becomes less fuel rich with increase in gasification temperatures. At atmospheric pressures the optimum equivalence ratio was found to be 3.0 for gasification temperatures in the range of 600-900 K, while it was 2.0 for gasification temperatures of 1000-1500 K and 1.5 for gasification temperatures of 1600-2500 K.