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US 6,960,291 B2Granted
Naphtha desulfurization method
AssigneesExxonMobil Research and Engineering Company, Merichem Company
InventorsMark A. Greaney, Binh N. Le, Daniel P. Leta, John N. Begasse, Charles T. Huang, Verlin Keith Turner
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Abstract
The invention relates to a method for desulfurizing naphtha boiling-range hydrocarbons such as cracked naphtha. More particularly, the invention relates to hydrotreating the naphtha under selective hydrotreating conditions, and then removing mercaptans from the hydrotreater effluent using a caustic extractant.
Claims24
A naphtha desulfurization method, comprising:
- (a) contacting a sulfur-containing naphtha with hydrogen in the presence of a catalytically effective amount of a hydrotreating catalyst under catalytic hydrotreating conditions to form a hydrodesulfurized naphtha;
- (b) contacting the hydrodesulfurized naphtha with a first phase of a treatment composition containing water, alkali metal hydroxide, cobalt phthalocyanine sulfonate, and alkylphenols and having at least two phases,
- (i) the first phase containing dissolved alkali metal alkylphenylate, dissolved alkali metal hydroxide, water, and dissolved sulfonated cobalt phthalocyanine, and
- (ii) the second phase containing water and dissolved alkali metal hydroxide;
- (c) extracting mercaptan sulfur from the hydrodesulfurized naphtha to the first phase;
- and
- (d) separating an upgraded naphtha having less mercaptan sulfur than the hydrodesulfurized naphtha.
4 more elements
A continuous method for treating and upgrading a selectively hydrotreated naphtha, comprising:
- (a) contacting a selectively hydrotreated naphtha under substantially anaerobic conditions with an extractant composition, wherein
- (i) the extractant is substantially immiscible with its analogous bottom phase of aqueous alkali metal hydroxide, and
- (ii) the extractant contains water, dissolved alkali metal alkylphenylate, dissolved alkali metal hydroxide, and dissolved sulfonated cobalt phthalocyanine;
- (b) extracting mercaptan sulfur from the naphtha to the extractant;
- (c) separating (i) an extractant containing mercaptan sulfur and (ii) an upgraded naphtha having less mercaptan sulfur than the selectively hydrotreated naphtha.
2 more elements
Dependencies are inferred from the claim text.