Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

摘要

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

主权项

1. A hydrothermal process for treating a wet biomass feedstock comprising biomass, inorganic contaminants, soluble sulfate contaminants, and sub-critical liquid water, the process operated at temperatures and pressures that maintain the wet biomass feedstock in liquid phase without forming a supercritical fluid and characterized by:
heating under pressure the wet biomass feedstock to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, and for preheating the wet feedstock in preparation for removal of the soluble sulfate contaminants; reacting the soluble sulfate contaminants with cations present in the feedstock to yield a sulfate-containing precipitate; and separating the precipitates of inorganic wastes and the sulfate-containing precipitates out the wet biomass feedstock to yield a liquid of the wet biomass feedstock having a decreased sulfate content.