1990 Volume 110 Issue 2 Pages 155-162
This paper describes a construction and a characteristics of a coal-gas-burned high efficiency power plant which emits no carbon dioxide (CO2) into the atmosphere. In a plant, CO2 gas and superheated steam are used as the main and the sub working fluid, respectively, of a closed dual fluid regenerative gas turbine power plant. Since coal gas composed of CO, H2, CO2 and CH4 is burnt in a combustor using oxygen, the exhaust gas led into a condenser includs only CO2 and H2O. Hence, CO2 gas can be easily separated at the condenser outlet from condensate. In the plant, the combustion gas is first used to generate power by driving a turbine. High-temperature turbine exhaust gas is next utilized at a regenerator to heat the main working fluid of CO2 gas flowing into the combustor, and then is utilized at a waste heat boiler to produce the superheated steam injected into the combustor. It is estimated that the power can be generated with gross thermal efficiency of 54.4%, and that the power generating efficiency is 46.7% which is calculated by subtracting the power required for producing the high-pressure oxygen used for combustion from the generator output. It is shown that the estimated efficiency is higher by 18.1 percentage points than that of a conventional boiler steam turbine power generating plant into which a process for removing and recovering CO2 from the stack gas by utilizing alkanolamine-based solvent is integrated.