Energy and capital cost analysis of CO2 capture in coal IGCC processes via gas separation membranes

In this study, the use of a hybrid coal integrated gasification combined-cycle (IGCC) system, consisting of a gasifier, a shift reactor and a membrane separator, has been examined. Two alternative separation options were studied: (a) low temperature separation, using polymer membranes, and (b) high temperature separation, by ceramic membranes. Single and multistage separation was examined for operation at 16 and 23 bar. The energy and cost analysis of the alternative cases show that CO2 removal in this hybrid IGCC scheme is technically feasible. Incorporation of shift reaction and membrane separators results in an energy penalty of 8–14% units, depending on pressure and staging, and in increased capital cost, especially for the ceramic membranes. However, this technology would permit reduction of CO2 emissions exceeding 50%, compared to conventional IGCC.