Exergoeconomic investigation of flue gas driven ejector absorption power system integrated with PEM electrolyser for hydrogen generation

This study aims to investigate the thermodynamic and economic aspects of a low temperature flue gas driven advanced absorption power cycle (AAPC) integrated to PEM electrolyser (PEME) for hydrogen and oxygen production. Flue gases from a small-scale coal fired power plant are utilized to energize the generator of the AAPC system. Produced power drives the PEME for primarily hydrogen generation, and oxygen as a byproduct. Use of ejector enhances the power production in the turbine favoring plant performance. The present integrated system produces daily amounts of ∼1.15 kg H2 and ∼4.59 kg O2 at 140 °C maximum cycle temperature with a capacity factor of 85%, 30 years of plant life and 5% annual interest rate. Cost of electricity and hydrogen are found to be 0.049 $/kWh and 2.43 $/kg, with overall energy and exergy efficiencies of 5.9% and 17.8%, respectively. The highest cost contributors are the APC turbine and the PEM electrolyser where these two accounts for almost 94% of total plant cost. Total cost of the plant is found to be ∼$61200. Cost of produced hydrogen shows promising results compared to those of electrolysis-based hydrogen production systems.