SUPERCRITICAL WATER GASIFICATION OF BIOMASS

Biomass gasification in supercritical water (SCW) is a clean and efficient method to produce hydrogen rich gas. This chapter focuses on the influence of different operating conditions on the hydrogen yield, carbon conversion efficiency (CE) and gasification efficiency (GE). SCW has unique physical and chemical properties which vary as temperature or pressure changes and it is an important factor to cause the variation of biomass gasification performance under various operating parameters. Thus this chapter details the properties of SCW and it also summarizes the literatures researching the effects of different operating parameters on CE and GE in recent years. The operating parameters include feedstock characteristics, biomass concentration, gasification temperature, reactor pressure, residence time and catalyst types and concentration. Some conclusions are presented and outlook is also briefly stated. The main contents in this chapter not only summarize the unique properties of SCW, but also review the experimental procedures of biomass gasification in SCW and the results of hydrogen yield, CE and GE under different conditions.