Carbon dioxide removal in power generation using membrane technology

Carbon dioxide separation by means of membranes from methane reformed synthesis gas and from semi-closed cycle flue gases has been studied. In the first case, removing carbon dioxide using membrane is more energy consuming than removing it, from the same synthesis gas, using chemical absorption, leading to overall energy conversion efficiency of about 39% for the recuperated-auto thermal reforming (R-ATR) cycle equipped with membrane vs. 45% for the same R-ATR equipped with chemical absorption. With reference to the semi-closed cycle, the net cycle efficiency in the case of membrane removal (42.7%) seems to be not very far from the chemical absorption case (46%). Finally, published data about CO₂ membrane separation specific cost have been analysed, showing that the membrane technology for flue gas application can be competitive with respect to chemical absorption if CO₂ flue gas concentration is higher than 10%.