A novel design for biogas-based power generation incorporating a coal-fired power plant

In this study, a hybrid power system was developed that includes biogas power generation and coal-fired power generation. The integration principle behind this system is as follows: the biogas obtained from anaerobic digestion is utilized by a gas turbine, and subsequently, the thermal exhaust from the gas turbine enhances the steam cycle of the coal-fired power generation system. Consequently, the energy derived from the gas turbine is transferred to the steam cycle of the coal-fired power plants, thereby improving the power generation efficiency of the entire coupling system. By considering the 162t/d biogas generator unit and the 350MW coal-fired generator unit as examples, a comprehensive evaluation of the design was conducted, taking into account thermodynamics. The results indicate that the integration has led to a 2.50 percentage point increase in the power generation efficiency of the coal-fired units, along with a net power generation of 20.97MW for the gas turbine.