Catalytic Steam Gasification of Biomass: Catalysts, Thermodynamics and Kinetics

The biomass steam gasification producing a synthesis gas with relatively higher hydrogen content is evolving significantly in recent year. Synthesis gas, produced from biomass, is required to be cleaned from trace amounts of H 2S, COS, CS 2, HCl, NH 3, and HCN at the ppb level. The products of biomass gasification depend on the various amounts of inorganic materials that yield ash during the gasification. Gasification of biomass with varying elemental compositions of organic matter can be assessed in a Van Krevelen's diagram in terms of hydrogen/carbon (H/C) and oxygen/carbon (O/C) ratios. Several pretreatments are performed in biomass gasification facilities in an effort to precondition the feedstock such as drying, size reduction, size fractionation, and leaching with water. The inorganic components of the biomass are usually converted into ash, which is removed from the bottom of the gasifier, or into fly ash, which leaves with the product gas during gasification.