Thermochemical conversion of biomass

Abstract

The present invention is directed to a process for the production of a syngas suited for further conversion to fine chemicals and/or automotive fuels from biomass by a thermochemical process conducted in a several steps procedure, said process comprising; a) Providing a stream of biomass material; b) Providing an aqueous alkaline catalyst stream comprising sodium and/or potassium compounds; c) Mixing comminuted biomass and alkaline catalyst and optional additives to form an alkaline biomass slurry or suspension; d) Treating alkaline biomass slurry or suspension in a hydrothermal treatment reactor at a temperature in the range of 200-400° C. and a pressure from 10-500 bar, forming a bio-oil suspension comprising liquefied biomass and spent alkali catalyst; e) Directly or indirectly charging the bio-oil suspension from step d), after optional depressurization to a pressure in the range 10-100 bar, heat exchange and separation of gases, such as CO2, steam and aqueous spent catalyst into a gasification reactor operating in the temperature range of 600-1250° C. thereby forming a syngas and alkali compounds; and f) Separating alkali compounds from a gasification reactor or from syngas and recycling alkali compounds directly or indirectly to be present to treat new biomass in the hydrothermal biomass treatment reactor of step d) and/or recycling aqueous alkali salts to a pulp mill chemicals recovery cycle.