The invention belongs to the technical field of
sulfur recovery, and particularly relates to a
sulfur recovery process for reducing SO2 emission. According to the
sulfur recovery process, a
thermal reaction unit, a catalytic reaction unit and a
tail gas purification unit are utilized; based on the traditional Claus and SCOT
tail gas treatment process, an
ammonia water absorption tank is additionally arranged for removing H2S from purified
tail gas, so as to ensure that the H2S content in the purified tail gas is lower than 5 mg / m<3>; waste
ammonia water is sent to a
sewage stripping unit for treating; through the adoption of the
sewage stripping device, H2S and
ammonia can be respectively extracted; the extracted H2S is returned to a sulfur recovery device for sulfur recovery, and the extracted ammonia is returned to the ammonia water absorption tank for cyclic utilization; finally, the
flue-gas SO2 emission concentration for the sulfur recovery device can be reduced below 100 mg / m<3>, the new
environmental protection standard to be executed is satisfied, and a novel method for building a new sulfur recovery device with a small investment and low
operating cost is provided. The sulfur recovery process is excellent in
absorption effect, simple to operate, low in expense, environment-friendly, and economical.