Research into CO2 mitigation and the production of clean fuels, particularly hydrogen, is essential to support the drive to reduce decrease pollution and greenhouse emissions. Membranes and carbon molecular sieves offer technoeconomical advantages and significant environmental benefits, since their application does not result in pollutant by-products, such as spent solutions and solids, requiring further treatment and disposal. In this study the use of a hybrid coal 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. 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 about 8 percent units, depending on pressure, 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. By applying propylene-nitrogen plasma treatment the selective adsorption of carbon dioxide over methane improved significantly. This technique can also be applied for the separation of other gases such as hydrogen and carbon monoxide with similar or more efficient results.