PROCESS FOR OPERATING A SULFURIC ACID PLANT

摘要

In a process for operating a plant for the production of sulfuric acid, wherein a sulfur trioxide containing gas is supplied to an intermediate absorption system or to a final absorber to be at least partly absorbed in sulfuric acid, wherein the intermediate absorption system comprises a two-stage absorption system, where in the 1st stage is a cocurrent absorber, and wherein the 2nd stage is designed as countercurrent absorber, and wherein the plant further comprises a heat recovery system to produce low pressure steam by using the heat generated by the exothermic absorption of the sulfur trioxide in the sulfuric acid, it is provided that a) when the heat recovery system is in operation, all acid withdrawn from the 1st stage absorber and from the 2nd stage absorber is circulated in an acid circuit of the 1st stage absorber, and b) when the heat recovery system is not in operation, no acid is fed to the 1st stage absorber and the 2nd stage absorber is fed from an independent acid circulation system.