Thermo-economic study of combined cycle power plant with carbon capture and methanation

Abstract

Present work considers a gas/steam combined cycle power plant at Auraiya, Uttar Pradesh, India having multiple units with total capacity of 663.36 MW for thermo-economic analysis after deploying carbon capture and storage in its one unit. Here the carbon dioxide captured from the plant is subjected to methanation to get methane, for use as fuel in gas turbine to augment the plant output and minimize carbon dioxide emission. The gas/steam combined cycle with carbon capture for methanation offers an increase in output from 229.6 MW without carbon capture and storage to 384.738 MW with carbon capture and storage at 1475 K turbine inlet temperature and 16.7 cycle pressure ratio. The improvement in work output is due to the conversion of captured carbon dioxide into methane and using this methane as a fuel in an additional gas turbine to produce additional work output. Economic analysis of this combined cycle produces electricity at the cost of 336074.76 US$ per MW.