Thermodynamic analysis of a multigeneration system based on biogas fired gas turbine for power, fresh water, heating and hydrogen production

Nowadays, one of the suitable technologies in terms of power generation and saving energy with high efficiency is using the multigeneration systems that renewable fuels are used as an alternative to fossil fuels. In the present study, a multigeneration system including biogas fired gas turbine, Organic Rankine Cycle (ORC), domestic water heater, Reverse Osmosis (RO) unit and Proton Exchange Membrane (PEM) electrolyzer. The proposed multigeneration system is assessed from energy and exergy viewpoints. After that, a comprehensive parametric study is carried out to show the effects of some key parameters (including pressure ratio of compressor, condenser pressure, evaporator temperature, preheater temperature and inlet temperature of gas turbine) on main performance criteria of the multigeneration system. Finally, the multi generation system is optimized from thermal efficiency point of view. The optimization results indicate that the thermal efficiency has optimum values for evaporator temperature and pressure ratio of compressor. Also, results show that the values of generated power, produced fresh water, thermal efficiency, exergy efficiency, produced hydrogen and total exergy destruction are calculated as 1192 kW, 5.584 kg/s, 55.74%, 30.56%, 1.455 kg/hr and 2827 kW, respectively.