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US 6,488,840 B1Granted
Mercaptan removal from petroleum streams (Law950)
AssigneeExxonMobil Research and Engineering Company
InventorsMark Alan Greaney, Michael Charles Kerby, Roby Bearden, Jr.
Life of this patent
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Abstract
This invention relates to reducing the amount of thiols (mercaptans) in petroleum streams, specifically, mercaptans above the five carbon molecular weight range.
Claims17
A method for removal of mercaptans from petroleum streams comprising the steps of:
- (a) extracting said petroleum stream, in the substantial absence of oxygen, with an aqueous medium comprising an aqueous base and a catalytically effective amount of a phase transfer catalyst or an aqueous solution of a catalytically effective amount of a basic phase transfer catalyst to remove said mercaptans from said petroleum stream;
- (b) Separating and recovering an aqueous stream containing mercaptide anions and a petroleum stream having a reduced amount of mercaptans, and wherein when said phase transfer catalyst is a quaternary ammonium hydroxide, said quaternary ammonium cation has the formula:
- where q=1/w+1/x+1/y+1/z and wherein q≧1.0, and wherein Cw, Cx, Cy, and Cz represent alkyl radicals with carbon chain lengths of w, x, y and z carbon atoms respectively.
A method for sweetening mercaptan containing petroleum streams comprising the steps of:
- (a) mixing said petroleum stream, in the presence of a sufficient amount of oxygen to oxidize the mercaptans contained in said petroleum stream to disulfides, with a medium consisting essentially of an aqueous base and a phase transfer catalyst (PTC) or an aqueous solution of a basic phase transfer catalyst to reduce the amount of said mercaptans from said petroleum stream
- (b) Separating and recovering an aqueous stream and a petroleum stream having mercaptans converted to disulfides therein.
Dependencies are inferred from the claim text.