Caustic treatment design, integration and waste disposal for gas plants

Gas processing plants offer a very different landscape than the typical oil refinery, and the methods used to treat sulfur (S) compounds in the liquids must be adjusted accordingly. When it comes to caustic treatment, one of the first configuration decisions is whether to treat the C3–C10+ NGL stream in a single unit or to fractionate prior to caustic treatment. Treating the entire hydrocarbon stream may result in less equipment, but fractionating can result in better selectivity for product specifications. Depending on the hydrocarbon source, LPG streams will have a vastly different distribution and concentration of mercaptan molecules, which require more rigorous removal methods. Some con