Sulphuric acid mfr. by multistage contact process - using hot charge and reaction gas for reheating gas passing from absorber to next contact stage

摘要

In H2SO4 mfr. from S by multistage oxidn. of SO2, the SO3 formed being removed in intermediate stages and after the end of oxidn., using multi-plate contact equipment, the gas from the first or second contact stage, after removal of SO3, is reheated to a temp. required in a 3-stage contact process first by gas passing to the first conversion stage and then by gas from the second and/or third stage, whilst final heating of the gas after the first plate is carried out with gas passing to the second stage and of the gas passing to the third stage by gas after the second plate of the first stage. The process has considerable elasticity. Even if there is a strong drop in the degree of conversion, operation of the contact zones in the first stage is possible.