Different Sulfur Recovery Options; Applicability, Advantages and Disadvantages

Environmental regulations have become more stringent on acid gas emissions to atmosphere. So, selecting the right process for sulfur recovery from refinery acid gases is very important. In this manuscript, different technologies for sulfur recovery have been reviewed and their advantages and disadvantages have been investigated. Selecting suitable technology depends on different parameters such as unit capacity, the feed composition, required recovery, operating condition and economy. The results of this study show that to obtain sulfur recovery about 97% at refineries with high capacity, the modified Claus process is the best choice. To achieve more recovery, one of the tail gas treatment technologies should be applied after Claus process. These technologies include sub-dew point, direct oxidation, converting sulfur species to H2S and absorb with selective amine, converting sulfur species to SO2 and absorb with suitable solvent. This study revealed that to increase sulfur recovery to more than 99.9%, the best choice is selective absorption of hydrogen sulfide with amine and recycling it to the Claus process.