Liquid LPG products from Atmospheric Distillation, Hydroprocessing, FCC, Visbreaking, Coking are valuable as commercial products, alkylation and oligomerization feedstock and for petrochemical applications.
Sulfur compound impurities in liquid LPG are mainly mercaptans (RSH), hydrogen sulfide (H2S) and carbonyl sulfide (COS). Mercaptans are undesirable because of their obnoxious odor and their tendency to hydrolyze, forming toxic and corrosive hydrogen sulfide.
- To reduce total sulfur content, an Extractive Sulfur Removal process which eliminates H2S in a first step and extracts mercaptans (RSH) in a second step is an ideal solution to meet the minimum total sulfur specification.
- To meet stringent copper strip corrosive specifications, an lpg sweetening step which convert acidic sulfur compounds into less aggressive disulfides will be an acceptable low investment alternative to pass the copper strip test and to protect downstream equipment.