Thermodynamic modeling and optimization of a combined biogas steam reforming system and organic Rankine cycle for coproduction of power and hydrogen

摘要: Abstract This paper aims to use waste heat of the biogas steam reforming (BSR) system for organic Rankine cycle (ORC) simultaneous power and hydrogen production. A comprehensive thermodynamic modeling proposed combined is carried out. In addition, optimization conducted, using genetic algorithm (GA). Four different working fluids R600, R245fa, R123, R113 are used in ORC, where among all them R600 recommended due its high performance environment benefits. Using as fluid results demonstrated that performs an optimum state based on selected objective functions when carbon molar ratio, dioxide methane reaction pressure, reactor temperature, pump pressure ratio pinch point temperature difference internal exchanger (IHE) set 2.99, 0.502, 1.004 bar, 998.85 K, 7.21 K, 5.44 K, respectively. this case, net output power, production rate, energy efficiency exergy obtained 15.9 kW, 0.02529 kg s−1, 45.63%, 74.89%, Moreover, analysis indicated components, recuperator accountable highest destruction through system. To better understand effect various parameters system, a parametric study some key main criteria performed. It concluded efficiencies BSR-ORC can be increased by increasing or decreasing IHE.