Process for removing sulfur compounds from hydrocarbon streams

A process for treating a liquid hydrocarbon stream containing H2S and mercaptans consisting essentially of:

• a) contacting the hydrocarbon stream with a weakly basic aqueous stream in an extraction column at extraction conditions, thereby extracting H2S and mercaptans into the basic stream;
• b) separating the basic stream from the hydrocarbon stream and collecting a treated hydrocarbon stream which passes the copper strip step;
• c) flowing the basic stream to a reactor and contacting the stream for a sufficient time with a sulfide oxidizing microorganism, at conversion conditions in the presence of sufficient oxygen, to convert the H2S to elemental sulfur and convert the mercaptans to disulfides;
• d) flowing the basic stream from step (c) to a first separation zone where the elemental sulfur is separated from the aqueous stream;
• e) flowing the basic stream effluent from step (d) to a second separation zone where the disulfides are separated from the basic stream to give a purified aqueous stream, which contains less than 0.08 g/l of sulfur;
• and
• f) recycling at least a portion of the purified basic stream to step (a).

A process for treating a hydrocarbon stream containing H2S and mercaptans consisting essentially of:

• a) contacting the hydrocarbon stream with a weakly basic aqueous stream in an extraction column at extraction conditions, thereby extracting H2S and mercaptans into the basic stream;
• b) separating the basic stream from the hydrocarbon stream and collecting a treated hydrocarbon stream which passes the copper strip test;
• c) flowing the basic stream, which contains from about 1 ppm to about 500 ppm by weight of hydrocarbons, to a reactor and contacting the stream for a sufficient time with a sulfide oxidizing microorganism, at conversion conditions in the presence of sufficient oxygen, to convert the H2S to elemental sulfur and convert the mercaptans to disulfides;
• d) separating the disulfides from the basic stream and flowing the basic stream to a first separation zone where the elemental sulfur is separated from the basic stream to give a purified basic stream, which contains less than 0.08 g/l of sulfur.