2 replies to this topic

[Babu Prasad]

We are experiencing high total sulphur in butane product in our NGL plant Merox unit outlet where the butane mercaptans being extracted by caustic circulation. Propane & Gasoline products also share the same caustic for extraction of mercaptans. The lean Caustic is washed by product Gasoline for removal any DSO content prior to entering into C4 extractor.
The lean caustic result shows, DSO content 140 ppm and Mercaptide 1ppm which is shows good oxidation of mercaptide into DSO.
DSO separator operates at 3.5 bar and DSO product separated at good rate. Butane product RSH shows only 2 ppm but total sulphur remains high. We had suspicious that DSO being reentering into C4 extractor with caustic and get into the butane product. But previously we had same DSO content in the lean caustic and butane total sulphur was not crossing 7ppm where as now it crossing 15ppm. I like to know anybody experienced this kind of problem of having high sulphur in butane product other than coming from DSO. Any other kind of sulphur contributes the total sulphur to goesup? Pls share your views.

[GAURANG PATEL]

Problem is with DSO removal facility. Try Heavy Naphtha instead fo Gasoline. DSO is getting carried over with caustic.

[Babu Prasad]

Problem is with DSO removal facility. Try Heavy Naphtha instead fo Gasoline. DSO is getting carried over with caustic.

Yes your correct, Total sulphur reduced after stopping Gasoline wash. Thanks.