This paper will explain how, by selecting the CANSOLV SO2 Scrubbing System for substantially cutting the SO2 emissions from its FCC unit off-gas rather than using a more conventional caustic scrubbing system, a Chinese refiner has unlocked a series of benefits. Its evaluation found the capital cost of the two solutions to be comparable, but it has avoided the costs associated with treating large amounts of liquid effluent, which are inevitable with caustic scrubbing, and improved its margins through the recovery of marketable sulphur.