A site trial demonstration of CO2 capture from real flue gas by novel carbon fibre composite monolith adsorbents

Abstract

A carbon fibre composite solid sorbent CO2 capture prototype unit was developed and site trialled at a coal-fired power station using actual flue gas. Over 200 test cycles of adsorption and sorbent regeneration were performed to evaluate the performance of the adsorbents. Under the study conditions, the CO2 adsorption efficiency of the carbon fibre composite adsorbents was found to be consistently over 98% with or without flue gas pre-treatment. The adsorption performance of the solid sorbents was maintained even after more than 200 tests and it was demonstrated for the first time that the carbon fibre composite solid sorbents were very stable under real flue gas conditions without any noticeable impact of SO2 and NOx on their CO2 adsorption performance. CO2 desorption efficiency of the adsorbent material using combined heat and vacuum swing was found to be between 90 and 95%. Besides, the adsorbents exhibited consistently very high removal performance of SO2 and NOx from flue gas and can very well eliminate the need for conventional chemical based caustic scrubber pre-treatment systems, which is generally required for solvent based capture processes. The carbon composite adsorption systems also have potential to be a pre-treatment or pre-cleaning technology, particularly for Australian coal-fired power stations which lack flue gas de-sulphurisation and de-nitrification facilities.