Patent ID: 7772449

Claim:
A process for removing acid components from a hydrocarbon containing gas stream, said process comprising: (a) feeding a gaseous feed stream comprising hydrocarbons, carbon dioxide, hydrogen sulfide and mercaptans to a caustic recirculation zone in a multi-stage caustic tower, wherein said multi-stage caustic tower has a least one said caustic recirculation zone and at least one once-through caustic zone located downstream of the caustic recirculation zone(s); (b) contacting said gaseous feed stream in said at least one caustic recirculation zone with a caustic stream that exits said tower and is recirculated to said tower to remove substantially all of said carbon dioxide and hydrogen sulfide from said gaseous stream and provide a partially treated gaseous stream comprising hydrocarbons and mercaptans; (c) passing said partially treated gaseous stream to said at least one once-through caustic zone; (d) contacting said partially treated gaseous stream in said at least once-through caustic zone with a caustic solution on a once-through basis to remove substantially all of the mercaptans from said partially treated gaseous stream and produce a product stream substantially free of carbon dioxide, hydrogen sulfide and mercaptans.