Sulphuric acid mfr. from sulphur di:oxide at elevated pressure - by catalytic oxidn., absorption and recirculation of non-oxidised gas using simple plant

摘要

In H2SO4 mfr. by catalytic oxidn. of SO2 with O2, recovery of the SO3 from the gas mixt. and recirculation of the unoxidised SO2 to the oxidn. stage, the process is carried out at a pressure of 2-20 (pref. 5-12) atmos. The process avoids the need for the complex construction of 4-stage contact appts., intensifies prodn. and permits the utilisation of large amts. of heat for high energy steam generation. No gas purificn. and drying stage is necessary. The use of a fluidised bed in the combustion of S vapour and oxidn. of SO2 and an immersion heat exchanger simplifies the construction of the plant and eliminates the gas heat exchanger.