In recent years, in developed countries, the extraction of electricity and heat in municipal sewerage refineries has become very common. This technology generates significant amounts of energy in the form of electricity and heat. In this article, we will get acquainted with a CHP system with an average capacity of 1 MW of electrical energy and 1.2 MW of thermal energy which is used in South Tehran sewerage refinery. Due to the significant sensitivity of the economic results to the parameter of revenue from the sale of electricity to the grid and a significant effect on reducing greenhouse gas emissions, a slight increase in the purchase rate of electricity generated from biogas digesters can make this investment more attractive to many domestic and foreign investors. Also, due to the environmental importance of the anaerobic digestion of sludge in municipal sewerage refineries, such projects can also be considered from an environmental point of view. If biogas is used as fuel for this CHP power plant, the efficiency will be 44.9%, and the reduction in heating and electricity costs also will be 8299.25 and 66895.38 , respectively. In the CHP cycle of this treatment plant, we hypothetically added a PEMFC and studied this cycle, Due to the addition of this system in the cycle, the electrical efficiency of the cycle increased and also, the emission of polluting gases from the CHP system is reduced due to the consumption of the biomass source تفاصيل المقالة