PURPOSE: To install a combined cycle power plant requiring no smokestack by feeding high temperature waste gas containing CO2 produced through blowing of combustion oxygen into a combustor to a heat accumulator thereby collecting waste gas from a combined cycle power plant incorporating an MHD generating system entirely in the form of liquefied CO2.
CONSTITUTION: A separator 20 separates the air into oxygen and nitrogen by means of an molecular adsorbent and thus separated oxygen is then blown into a combustor 21 where it is burnt together with fuel to produce high temperature waste gas containing CO2. The high temperature waste gas is then fed to a heat accumulator 23 where it is heated and then fed to an MHD generator 24 in order to generate power. The waste gas is heat exchanged with rare gas in the heat accumulator 23 and then fed to a gas turbine 29 which is thereby driven to drive a generator G2 and generate power. The waste gas is then fed from a heat recovery boiler 28 to a CO2 pressurizing unit 31 coupled through a gas compressor 30 with the gas turbine 29 and the CO2 pressurizing unit 31 pressurize the waste gas to produce liquefied CO2 which is then collected and discarded to the ocean or the like.