ZECOMIX: Performance of alternative lay-outs

ZECOMIX is a plant for hydrogen production and power generation using coal as a primary energy source and with nearly zero emissions. The global lay-out can be divided in 5 sectors: coal gasification, O2 production, CO2 capture, CO2 sequestration, power generation. Coal is hydro gasified using a stream of hydrogen internally recycled. The syngas, mainly methane, is then reformed with steam and CaO in such a way to obtain a gaseous stream of hydrogen and steam separated from CaCO3 which is solid. CaO is then regenerated inside a calciner which produce also a gaseous stream of CO2 which has to be stored. The stream of hydrogen is burned with stoichiometric O2 and the resulting steam is expanded in a steam power plant. After having focused our efforts on the coal gasification and CO2 capture, we selected a layout for these sections and analysed the possibility to cogenerate hydrogen and power. The results confirmed that cogeneration is the most efficient solution and ZECOMIX seems to be an interesting option.