Effects of operating parameters on performance of product gases from cellulose gasified in supercritical water

Operating parameters have direct decisive role on performance of product gases from biomass gasified in supercritical water. Combining with chemical equilibrium two-phase model on the basis of Gibbs free energy minimum and experimental results, the effects of reaction temperature, pressure and concentration of feedstock on higher heating value and gasification efficiency of product gases were investigated. The results show that before cellulose does not gasify completely, gasification efficiency increases with temperature, but higher heating value decrease, so high temperature is favorable to hydrogen production, but is not fit for producing combustible gases. Pressure has a little effect on gasification efficiency and higher heating value; it's feasible to choose a little one higher than supercritical water pressure; high concentration of feedstock is hard obviously to gasify, the mixture of Raney-Ni and ZnCl2 may have a good catalysis. All these conclusions drawn here are very important to the process optimization and the development of this technology on a large scale.