Designing a 200 MWth biomass chemical looping gasification unit for high-quality syngas production with high CO2 capture rates

Biomass Chemical Looping Gasification (CLG) is a novel process to produce high quality syngas without oxygen requirement while CO 2 emission to the atmosphere is avoided. CLG is based on the partial oxidation of the fuel by means of an oxygen carrier, which is continuously regenerated with air by circulating between two interconnected fluidized bed reactors, namely fuel and air reactors. In this work, the design of a 200 MW th CLG unit for syngas production from biomass is presented and optimized after the modelling and simulation of the fuel reactor of this unit. The reactor model was based on a macroscopic fluid dynamic model, and the most relevant chemical processes involving the biomass conversion were included. Modelling results showed that the air to fuel ratio mainly affects the syngas yield, while the fuel reactor temperature affected highly the char conversion. It was shown that the char conversion in a CLG unit does not affect the syngas yield, but rather influences the carbon fraction either oxidized to CO 2 or emitted to the atmosphere from the air reactor or captured in the syngas products from the fuel reactor. Main key performance parameters included syngas and hydrocarbons yields of 0.76 and 0.13 S.T.P. m 3 /kg dry biomass and cold gas efficiency of 73 %. • Identified key aspects on the design of a 200 MW th unit BCLG from reactor modelling. • Oxygen transference control by the air ratio is the preferred option. • Syngas yield was affected by the air ratio, but it was constant regardless the char conversion. • Suitable design and conditions identified to get high CO 2 capture rates.