Assessment of calcium-based chemical looping options for gasification power plants

This paper evaluates various calcium-based chemical looping concepts to be applied in Integrated Gasification Combined Cycle (IGCC) plants for decarbonised energy vectors poly-generation (with emphasis on power generation and hydrogen and power co-generation). Two calcium-based chemical looping configurations were analysed. The first concept is based on post-combustion capture using the flue gases resulted from the power block (combined cycle gas turbine). The second concept is based on pre-combustion capture, the calcium-based chemical looping systems being used simultaneous to capture carbon dioxide (by sorbent enhanced water gas shift) and to concentrate the syngas energy in the form of hydrogen-rich gas.The paper assess in details coal-based IGCC with calcium carbonate looping cycle used for power generation. Net power output is in the range of 550–600 MW with more than 95% carbon capture rate. Critical design and operation factors like process integration, heat and power integration, quality specification of captured CO2 stream were evaluated in details. The hydrogen and power co-generation scenario (in the range of 0–200 MW hydrogen) was also evaluated as a potential way to improve the plant flexibility. IGCC power plant without carbon capture was also considered to quantify the energy penalty for carbon capture cases.

► Calcium-based looping cycle offers reduced carbon capture energy penalty.
► Chemical looping cycles ensures almost total decarbonisation rate of the fuel used.
► Increasing energy efficiency and plant flexibility by H2 and power co-generation.
► Energy integration techniques to optimise the overall plant energy efficiency.