A new principal design of a sustainable power plant to produce combined Hydrogen-Carbon dioxide fuel for industrial applications

Abstract

In this paper, an innovative geothermal-based hybrid energy structure incorporated with power production units and industrial fuels is developed and evaluated. This integrated structure comprises an organic Rankine cycle power plant, lead-acid battery, proton exchange membrane electrolyzer, and oxyfuel power plant to generate power, hydrogen, and liquid carbon dioxide simultaneously. The comprehensive energy, exergy, exergoeconomic, and sensitivity analyses are conducted. The geothermal unit provides 9390 kW thermal power to run the organic Rankine cycle, which is designed using different working fluids to produce initial power to drive the water electrolyzer system (453 kW initial power). The electrolyzer system produces 80 m 3 /h hydrogen as the main product to be stored in a reservoir and 40 m 3 /h oxygen to drive an oxyfuel power plant that generates 41.11 MW power with 79.91% exergy efficiency. The amount of liquid carbon dioxide production is around 10.186 kg/s. For specified conditions, the total power generation is about 42 MW and the exergoeconomic analysis illustrates that the maximum capital cost occurs in oxyfuel power plant’s compressors and turbines with 938.31 $/h and 732.45 $/h, respectively. The proposed integrated structure can certainly provide a new approach toward generating power and industrial fuels utilizing geothermal renewable energy sources.