OICC Press International Journal of Energy and Environmental Engineering 2251-6832 17 01 2026 03 31 Thermodynamic Simulation of An Innovative Combined System Including CO2 Power Cycle and Organic Rankine Cycle in Order to Reduce CO2 Emission 10.57647/ijeee.2026.1701.03 EN Abdulla Ammer Abdulkader Department of Mechanical Engineering, ST.C., Islamic Azad University, Tehran, Iran Alireza Saraei Department of Mechanical Engineering, ST.C., Islamic Azad University, Tehran, Iran Hossein Ahmadi Danesh Ashtiani Department of Mechanical Engineering, ST.C., Islamic Azad University, Tehran, Iran Mohsen Jabbari Department of Mechanical Engineering, ST.C., Islamic Azad University, Tehran, Iran Journal Article 2026 03 31 In this research, by simulating the newly invented Allam cycle and creating a combined cycle based on Allam, the CO2 produced in the Allam cycle is used as the working fluid and in addition to reducing the greenhouse effect, the energy wasted in the Allam cycle will be used as the energy supplier for two medium temperature and low temperature cycles. Reducing energy waste by creating a new combined cycle will lead to an increase in the LHV efficiency of the power plant and consequently reduce global warming and environmental hazards.Using Thermoflow software, the Allam cycle, organic Rankine cycle, and Rankine cycle were simulated, and then the aforementioned cycles were combined to reduce energy loss and the results were examined. The simulated combined cycle, in an ideal case, will increase LHV by 0.5% compared to the Allam cycle, and by considering the energy loss by the components in the Allam cycle, and then creating a combined cycle, it will increase efficiency by 0.98%. The creation of a combined cycle led to a reduction in energy loss in the system. The CO2 produced in the power plant was contained in the system and also by examining the environmental conditions of the power plant and increasing the pressure to 1.127 bar, relative humidity of 10 %, and temperature of zero degrees, the LHV efficiency of the power plant increased. Increasing the efficiency of the power plant, reducing energy loss, and also absorbing CO2, all will lead to a reduction in global warming and increasing environmental protection.