Energy, exergy, economic and environmental analysis and optimization of a novel biogas-based multigeneration system based on Gas Turbine-Modular Helium Reactor cycle

摘要

Biogas for supply of power plants can play a paramount role in reducing greenhouse gas emission and extra cost of a fossil fuel based plants. Regarding this aspect of biogas heat source, a novel biogas-based multigeneration system is proposed and modeled under privilege of first and second laws of thermodynamics, economic, and environmental perspectives. Furthermore, multi-criteria optimization of this integrated system is carried out from 4E (energy, exergy, exergoeconomic, and environmental) analysis standpoints. The introduced multigeneration system is able to produce optimum cooling capacity, heating capacity, net power, distilled water, and hydrogen of 123.59 MW, 0.73 MW, 280.35 MW, 18.14 kg/s, and 0.2432 kg/s, respectively. Under this circumstance, the thermal efficiency, exergy efficiency, unit product cost (UPC) of the system, and environmental penalty cost rate are calculated 72.75%, 50.21%, 6.79 $/GJ, and 168 $/h, respectively. Additionally, among all components, reactor core and among different sub-systems, the gas turbine-modular helium reaction (GT-MHR) cycle has the highest contribution to the overall exergy destruction. Finally, a complete sensitivity study based on key thermodynamic, thermoeconomic, and environmental parameters is performed and results are extended and discussed.