Biomass oxy-gasification integrated into a coal oxy-boiler.

Abstract

A biomass gasifier coupled to an oxy­combustion boiler is an attractive concept, enabling simultaneous production of syngas of medium heating value and carbon “capture” from concentrated CO2 taken from the flue­gas of an oxyboiler. Pure oxygen is available for the gasifier, because it is produced for the oxyboiler, taking advantage of the economy of scale of the coal plant. A model of the gasifier is used to study the effect of process conditions on the gas composition and efficiency. The potential use of the gas produced for various applications (co­combustion in the oxyboiler, electricity production in gas engines and synthesis of chemicals with and without CO2 separation are discussed. The capability of sequestration of green CO2 (from biomass) is discussed. A 3 MWth bubbling fluidized bed gasifier in León (Spain) has been erected to demonstrate the viability of this gasification process.