This research presents thermodynamic analysis and optimization of a biogas-fed integrated plant designed to generate power, cooling, and hydrogen (H2) simultaneously. Utilizing biogas as the mainly energy resource, the system integrates power generation with an organic Rankine cycle (ORC), cooling through absorption refrigeration (ARS), and H2 generation via steam reforming. The research focuses on maximizing energy efficiency by conducting both energetic and exergetic analyses while advanced optimization techniques are applied to define the optimal working conditions. According to the analysis results, the gas turbine (GT) cycle produces 33233 kW, the supercritical carbon dioxide (sCO2) cycle 5159.5 kW, the liquified natural gas (LNG) turbine 1000.7 kW, and the transcritical carbon dioxide (tCO2) cycle 498.02 kW. The cooling cycle power output is 473.52 kW. It was also concluded that the H2 production of the hybrid plant is 7.265 kg/h. The analysis results stated that the hybrid system’s most destructive part was the combustion chamber (CC), which had 61 % (27029 kW). Additionally, the sustainability index (SI) analysis shows that the sCO2-BC pressure ratio and the GT pressure ratio significantly impact SI. According to the optimization results, the optimum conditions of the biogas-fed trigeneration system were determined using a multi-objective optimization method. It was found that in the selected optimum condition, the total energetic efficiency and exergy destruction rates are 50.69 % and 42590.74 kW. The consideration of scatter distribution of the decision variable offers that selecting the sCO2 pressure ratio (PR) in the upper bound of the allowable range can improve both total energy efficiency and exergy destruction ratio as objective functions.
