The invention provides a device and a process for preparing
sulfuric acid from wet-process
acid gas, the device comprises an incinerator, a first
waste heat boiler, a
sulfur dioxide converter, a second
waste heat boiler, a condenser and an
activated carbon reactor which are sequentially connected through a pipeline, and the
sulfur dioxide converter comprises four catalyst
bed layers which are sequentially arranged from top to bottom; two air supplement valves and two interlayer heat exchangers are arranged on the
sulfur dioxide converter; and a return
pipe is communicated between the
activated carbon reactor and the condenser. The process provided by the invention can treat various working conditions of feed gases with different concentrations, can adjust the
oxygen concentration in the catalyst
bed layer according to the change of the feed
gas concentration, performs emergency cooling on the catalyst
bed layer when an overtemperature phenomenon occurs in the catalyst bed layer, and adopts an
activated carbon reactor at the
tail end to adsorb and convert
sulfur dioxide to obtain dilute
sulfuric acid. Dilute
sulfuric acid flows back to the condenser to spray
sulfur trioxide, sulfuric acid with
high concentration is obtained, no waste water is generated in the whole process, and
tail gas is discharged after reaching the standard.