Electrochemical treatment of heavy oil streams followed by caustic extraction
AssigneeExxonMobil Research and Engineering Company
InventorsMark A. Greaney, Kun Wang, Frank C. Wang
Life of this patent
Estimating the term…
Abstract
This invention relates to a process for electrochemical conversion of dibenzothiophene type molecules of petroleum feedstreams selectively to mercaptan compounds that can then be more easily removed from the electrochemically treated product stream by either caustic extraction or thermal decomposition of the thiol functionality to hydrogen sulfide. The conversion of dibenzothiophenes to mercaptans is performed by electrochemical means in the substantial absence of hydrogen and in the substantial absence of water.
Claims22
A process for removing sulfur from a sulfur-containing petroleum feedstream having at least a portion of its sulfur in the form of hindered dibenzothiophene compounds, comprising:
- a) passing a sulfur-containing petroleum feedstream to an electrochemical cell in the substantial absence of hydrogen and water;
- b) subjecting said sulfur-containing petroleum feedstream to an effective voltage and current that will result in the conversion of at least 5 wt % of said hindered dibenzothiophene compounds wherein at least 25 wt % of these converted hindered dibenzothiophene compounds are mercaptan compounds, thereby producing an electrochemically treated petroleum feedstream;
- c) passing the electrochemically treated petroleum feedstream containing said mercaptans compounds to a mercaptan treatment zone wherein it is contacted with an aqueous caustic solution wherein mercaptan-containing compounds are extracted by the aqueous caustic solution;
- and
- d) collecting a reduced mercaptan sulfur petroleum product stream from the mercaptan treatment zone;
- wherein the reduced mercaptan sulfur petroleum product stream has a lower sulfur content by wt % than the electrochemically treated petroleum feedstream.
Dependencies are inferred from the claim text.