GB709640A - Improvements relating to the production of gases containing sulphur dioxide and sulphur trioxide - Google Patents

Abstract

The working fluid of a gas turbine plant is heated indirectly in a heat exchanger by the heat set free in a plant for the production of gases containing sulphur dioxide by roasting sulphuric materials and of gases containing sulphur trioxide by catalytically oxidizing the roaster gas after purification and drying. The source of heat may be the roasting plant, the sensible heat of the hot impure roaster gas or the sensible heat of the reaction gas leaving the catalytic plant. The working fluid is preferably compressed to about 4 to 10 atmospheres pressures and heated in 700 DEG C. This fluid is heated to about 250 DEG C. by indirect heat exchange with the gases leaving the catalytic plant so that the surfaces in contact with the hot impure roaster gases cannot be over-cooled. The turbine may drive a blower for compressing the working fluid together with blowers for the air and gas of the roaster plant. The working fluid is preferably purified roaster gas in which case the turbine discharges into the catalytic and absorption plant and the temperature of the exhaust corresponds to the temperature at which the catalyst initiates the reaction. If desired, the working fluid may be expanded to a lower temperature and then heated to the reaction temperature by the gases leaving the first reaction stage of the catalytic plant or by mixing with hot gas which is passed around the turbine. In another arrangement, the gases are expanded to a temperature which is higher than the reaction temperature and cooled to the reaction temperature by cold air or roaster gas purified at low temperature.