Hydrogen production using waste heat recovery of MATIANT non-emission system via PEM electrolysis

In order to power and hydrogen production, combination of Matiant cycle with an ORC cycle and PEM electrolysis have been analyzed from the viewpoint of energy and exergy. Waste heat of the Matiant cycle is used to run the ORC cycle. Effect of some decision variables i.e. evaporator temperature, minimum temperature difference in heat exchanger, degree of superheating in ORC turbine inlet and isentropic efficiency of ORC turbine on the rate of produced hydrogen, ORC produced power and exergy efficiency of the combined system have investigated. It is observed that, increasing minimum temperature difference leads to decrease in the rate of produced hydrogen, ORC produced power and consequently exergy efficiency of the combined system. Also change in the evaporator temperature makes an optimum value of rate of produced hydrogen, ORC produced power and therefore the exergy efficiency of the combined system. It is obtained that, rising the degree of superheating in the ORC turbine inlet decreases the rate of produced hydrogen, ORC produced power and the exergy efficiency of the combined system. As it was expected, increasing isentropic efficiency of ORC turbine leads to an increase in rate of produced hydrogen, ORC produced power and therefore the exergy efficiency of the combined system.