A refiner's ability to reduce the sulphur content of FCC gasoline may be limited by the molecular species that are present in the FCC unit. Numerous sulphur containing species including mercaptans, sulphides, disulphides, thiophenes, and benzothiophenes are present in the gasoline. Their concentration varies depending upon the original crude source, the boiling ranges of feedstocks, and their historical treatment.
To achieve the reduction in gasoline sulphur, the refiner has a number of options to choose from. Most options involve trade-offs between high capital costs and gasoline yield loss. However the use of sulphur reducing additives, such as INTERCAT LGS additives, offer an economically attractive alternative. These additives can provide the refiner with a capital free option to reduce gasoline sulphur upwards of 40% without the loss of gasoline yield.