Catalysis in Supercritical Water Gasification of Biomass: Status and Prospects

Abstract

High pressure and temperature demand containment structure of costly alloys for the supercritical water gasification (SCWG) apparatus. The catalyst is of great significance for realizing high gasification efficiency of biomass under milder circumstances in supercritical water (SCW). This chapter gives a comprehensive review on the original work in the area of catalysis in SCWG of biomass. The development status and role of different catalysts including homogeneous and heterogeneous catalysts used in SCWG were discussed. The alkali catalyst is a homogeneous catalyst, which has a key role in the SCWG of model compounds, biomass, organic wastes and coal. As a heterogeneous catalyst, Ni has been widely used in sub or supercritical water gasification due to its low cost and high activity. The crystallite sintering, supports' breakdown and carbon deposition under SCW conditions will cause deactivation of catalysts. Therefore, the work of the Ni catalysts modification mentioned in this chapter is necessary and of great value.