Pre-combustion carbon dioxide capture by gas–liquid absorption for Integrated Gasification Combined Cycle power plants

Abstract

Among various configurations of fossil fuel power plants with carbon dioxide capture, this paper focuses on pre-combustion capture technology applied to an Integrated Gasification Combined Cycle power plant using gas–liquid absorption. The paper proposes a detailed study and optimization of plant design (column height and packed dimensions) with CO2 capture process using different solvents as: aqueous solutions of alkanolamine, dimethyl ethers of polyethylene glycol, chilled methanol and N-Methyl-2-pyrolidone. By developing simulations in Aspen Plus, the following performance results of these physical and chemical solvents, mentioned above, are discussed: overall energy consumption (power consumption, heating and cooling agent consumption), CO2 specific emissions, net electric power output and plant efficiency. The paper presents as well, the total investment capital cost of an IGCC coal mixed with biomass (sawdust) power plant generating 425–450MW net electricity with (70% CO2 capture, 80% CO2 capture and 90% CO2 capture) and without pre-combustion CO2 capture.Simulation results show that for evaluated solvents for CO2 capture, the physical solvent, dimethyl ethers of polyethylene glycol, is more energy efficient that the other physical and chemical solvents investigated. Regarding the economic study, implementation of pre-combustion CO2 capture on IGCC plant, using dimethyl ethers of polyethylene glycol, leads to an increase of the capital cost with about 19.55% for 70% CO2 capture, 20.91% for 80% CO2 capture and 22.55% for 90% CO2 capture.