Simulation and economic evaluation of heat and power generation from flare gases in a combined cycle power plant

Abstract

In recent decades, the release of flare gases from different units of chemical industries into the atmosphere has become a substantial environmental problem all around the world. Therefore, recovery or use of flare gases has become much more critical. Combined heat and power generation from flare gases is one of the most economical methods for recovering flare gases. Two power generator gas cycle power plant or a combined cycle power plant can be used to generate heat and power. In this research, simulation and economic evaluation of heat and power generation from flare gases in a gas cycle power plant and combined cycle power plant using PRO/II v.10 software. Finally, by changing the effective operating parameters such as air to treated flare gas ratio, the outlet pressure of compressors, outlet pressure of steam and gas turbine, outlet pressure of pumps and adiabatic efficiency steam and gas turbine, heat and power generation and total capital and operating cost were investigated and analyzed. The results of simulation and sensitivity analysis showed that the use of flare gas with a mass flow rate of 9700 kg/h (mole fraction of CH4: 0. 84) could be used to construct a combined cycle power plant with a capacity of 115 MW with an investment cost of 100 M$. This value of energy surpasses the need for an average community with 85000 families, and the excess can be sold to the national grid.