Comparative thermoeconomic analysis of integrated hybrid multigeneration systems with hydrogen production for waste heat recovery in cement plants

The cement industry is a widely used and energy-consuming sector, making it one of the largest CO2 emitters, primarily to meet its energy demands. Therefore, this research aims to evaluate the waste heat recovery process from a cement factory to fulfill a portion of its energy requirements. In this study, four scenarios have been evaluated, including power production scenarios, hydrogen production scenarios, methanation production process evaluation scenarios, blending hydrogen with natural gas, oxy-fuel combustion scenarios, and scenarios for producing the required freshwater for the factory and the water electrolysis process. The results show that the steam Rankine cycle with the reheating process and the organic Rankine cycle with methanol working fluid with a production capacity of 24.35 MW, and a payback period of 2.4 years with levelized cost of energy being 0.005809 $/kWh, is the most favorable scenario for the power generation cycle. Also, the process of alkaline electrolysis with a hydrogen production rate of 0.1648 kg/s, and a payback period of 5.816 years, and also with the levelized cost of hydrogen being 1.001 $/kg, happened to be the most suitable hydrogen production scenario compared to other electrolysis scenarios such as PEM and SOEC. Moreover, the process of water desalination by reverse osmosis with the energy consumption of 2.7 MW of power is capable of supplying all the required water of the factory and the water electrolysis process, and it was determined as the most suitable scenario for supplying the required water.