Possible optimal configurations for the ZECOMIX high efficiency zero emission hydrogen and power plant

Coal use for electricity generation will continue growing in importance. In the present work the optimization of a high efficiency and zero emissions coal-fired plant, which produces both hydrogen and electricity, has been developed. The majority of this paper concerns an integration of gasification unit, which is characterized by coal hydrogasification and carbon dioxide (CO2) separation, with a power island, where a high-hydrogen content syngas is burnt with pure oxygen stream. Another issue is the high temperature CO2 desorption. Because of the elevated temperature heat supply, the regeneration process affects the overall performance of ZECOMIX plant. An advanced steam cycle characterized by a medium pressure steam compressor and expander has been considered for power generation. A preliminary study of different components leads to analyze possible routes for optimization of the whole plant. The plant equipped with a CO2 capture unit could reach efficiency close to 50%. The simulations of a thermodynamic model were carried out using the software ChemCAD.