Integrated hydrocarbon desulfurization with oxidation of disulfides and conversion of so2 to elemental sulfur

Patent metadata

Field	Value
Publication number	US-2016145502-A1
Application number	US-201414552222-A
Country	US
Kind code	A1
Filing date	Nov 24, 2014
Priority date	Nov 24, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A process to produce a sulfur-free hydrocarbon product stream from a liquid hydrocarbon disulfide product, e.g., of the Merox Process, includes subjecting the hydrocarbon disulfide to a catalytic oxidation step to produce SO 2 which is separated from the remaining desulfurized hydrocarbons that form the clean sulfur-free hydrocarbon product stream; the SO 2 is introduced into a Claus processing unit with the required stoichiometric amount of hydrogen sulfide (H 2 S) gas to produce elemental sulfur.

First claim

1 . In the process for treating a liquid hydrocarbon feedstream to remove mercaptans present in the stream by
a. contacting the mercaptan-containing hydrocarbon feedstream with an aqueous caustic solution to oxidize the mercaptans and produce a spent caustic solution and mercaptan-free hydrocarbons; b. subjecting the spent caustic and hydrocarbons to a wet air oxidation step to regenerate the spent caustic and produce a liquid hydrocarbon disulfide product; c. separating the regenerated aqueous caustic solution from the hydrocarbon disulfide and recycling the caustic to step (a);
the improvement comprising:
d. oxidizing the hydrocarbon disulfide product to sulfur dioxide and a hydrocarbon product stream that is substantially free of sulfur;
e. separating and recovering the hydrocarbon product stream;
f. reacting the sulfur dioxide with H 2 S in a predetermined stoichiometric ratio to produce an elemental sulfur product and water; and
g. recovering the sulfur.

2 . The process of claim 1 in which the caustic is selected from the group consisting of aqueous solutions of sodium hydroxide, ammonia, potassium hydroxide, and combinations thereof.

3 . The process of claim 1 which includes subjecting the H 2 S to an oxidation reaction to convert a predetermined portion of the H 2 S to sulfur dioxide in order to achieve a stoichiometric ratio of 2H 2 S:SO 2 to complete the sulfur-producing reaction:
2H 2 S+SO 2 →3S+2H 2 O.

4 . The process of claim 1 in which the hydrocarbon disulfide is oxidized in the presence of a catalyst.

5 . The process of claim 4 in which the catalyst is selected from the group consisting of catalytic compositions comprising copper oxide in an amount ranging from 10 weight percent (wt %) to 50 wt %, zinc oxide in an amount ranging from 5 wt % to less than 20 wt %, and aluminum oxide in an amount ranging from 20 wt % to 70 wt %, wherein said catalytic composition has an X-ray amorphous oxide phase, and a formula CuxZn 1-x Al 2 O 4 , wherein x ranges from 0 to 1, highly dispersed crystalline ZnO and CuO alone and said composition further comprises CeO 2 in the form of particles ranging in diameter from 5 nm to 10 nm, in an amount ranging from 0.1 wt % to 10 wt % of said catalytic composition, and combinations thereof.

6 . The process of claim 5 in which the catalyst composition comprises from 20 wt % to 45 wt % CuO, from 10 wt % to less than 20 wt % ZnO, and from 20 wt % to 70 wt % A 2 O 3 .

7 . The process of claim 6 in which the catalyst composition comprises from 30 wt % to 45 wt % CuO, from 12 wt % to less than 20 wt % ZnO, and from 20 wt % to 40 wt % Al 2 O 3 .

8 . The process of claim 4 in which the oxidation catalyst is CuCr 2 O 4 /CeO 2 /Al 2 O 3 .

9 . The process of claim 1 in which the liquid hydrocarbon disulfide product has a sulfur content in the range of from 10 to 60 wt %.

10 . The process of claim 1 in which the hydrocarbon disulfide is contacted with the oxidation catalyst at a temperature in the range of from 200° C. to 600° C., and in certain embodiments from about 250° C. to about 550° C., and in further embodiments from about 300° C. to about 500° C.

11 . The process of claim 4 in which the hydrocarbon disulfide is contacted with the oxidation catalyst under conditions that include a molar ratio of O 2 :C in a range of from 1:100 to 1:10, in certain embodiments from 1:50 to 1:10, and in further embodiments from 1:20 to 1:10, and a molar ratio of O 2 :S is in the range of from 1:1 to about 150:1, in certain embodiments from 10:1 to 100:1, and in further embodiments from 20:1 to 50:1.

12 . The process of claim 4 in which the hydrocarbon disulfide is contacted with the oxidation catalyst under conditions that include a weight hourly space velocity (WHSV) that is in the range of from 1 h−1 to 100 h−1, in certain embodiments 5 h−1 to 50 h−1, and in further embodiments 10 h−1 to 30 h−1.

13 . The process of claim 4 in which the hydrocarbon disulfide is contacted with the oxidation catalyst under conditions that include a gas hourly space velocity (GHSV) that is in the range of from 1,000 h−1 to 25,000 h−1, in certain embodiments from 5,000 h−1 to 15,000 h−1, and in further embodiments 5,000 h−1 to 10,000 h−1.

14 . The process of claim 4 in which the hydrocarbon disulfide is contacted with the oxidation catalyst under conditions that include an operating pressure that is in the range of from 1 bar to 30 bars, in certain embodiments from 1 bar to 10 bars, and in further embodiments from 1 bar to 5 bars.

15 . The process of claim 4 in which the hydrocarbon disulfide is contacted with the oxidation catalyst under conditions that include an operating pressure that is in the range of from 1 bar to 5 bars, a weight hourly space velocity (WHSV) that is in the range of from 10 h−1 to 30 h−1, and a gas hourly space velocity (GHSV) that is in the range of from 5,000 h−1 to 10,000 h−1.

Assignees

• Saudi Arabian Oil Co

Inventors

• Koseoglu Omer Refa

Classifications

• C10G27/06 Primary

  in the presence of alkaline solutions · CPC title

• C01B17/0253

  from non-gaseous sulfur compounds other than sulfides or materials containing such sulfides · CPC title

• C01B17/04 Primary

  from gaseous sulfur compounds including gaseous sulfides · CPC title

• B01D53/523

  Mixtures of hydrogen sulfide and sulfur oxides · CPC title

• B01D53/50

  Sulfur oxides (B01D53/60 takes precedence) · CPC title