Abstract: In an electric energy generating plant including a coal gasification arrangement and a combined gas turbine and steam combine, hot raw gas generated in the gasification arrangement is fed via a heat-exchanging and dust separating unit into a desulfurization unit from which cool purified gas is discharged. The heat exchanging unit includes a tubular pressure resistant housing serving as a feeding passage for the hot raw gas and enclosing a coaxial arrangement of a tubular pipe-wall housing of a waste-heat recovery boiler, and pipe spirals of a raw gas/purified gas heat exchanger. The waste-heat recovery boiler delivers superheated steam to the steam turbine and the raw gas/purified gas heat exchanger delivers heated purified gas to the gas turbine.