ZECOMIX is a plant for hydrogen production and power generation using coal as a primary energy source and with nearly zero emissions. The project is financed by the Italian Government and the partners are ENEA, Ansaldo and CIRPS (a consortium of Universities involved in researches on sustainable systems). The research unit of Cassino is involved in the design and the analysis of lay-outs alternative to the reference one. The global lay-out can be divided in five sectors: coal gasification, O₂ production, CO₂ capture, CO₂ sequestration, power generation. At first we focused our efforts on the coal gasification and CO₂ capture which are strictly interconnected. Actually coal is gasified with hydrogen (hydrogasification) producing a syngas which is fed to a reformer filled with calcium oxide. Almost all the methane reacts with the calcium oxide and the result is a stream of hydrogen and steam which is partially recycled to the hydrogasifier and partially fed to the power plant. The calcium carbonate is calcined in order to regenerate the calcium oxide and to recover a stream of carbon dioxide. The system is quite complex and shows some engineering problems. We proposed several changes and simulated the different lay-outs designed. Some of the proposals resulted in a significant decrease of efficiency (7-8%), while other proposals allowed to obtain some improvements (1-2%) and to simplify plant lay-out.