Process for oxidizing one or more thiol compounds

Patent metadata

Field	Value
Publication number	US-2018201575-A1
Application number	US-201815863752-A
Country	US
Kind code	A1
Filing date	Jan 5, 2018
Priority date	Jul 8, 2015
Publication date	Jul 19, 2018
Grant date	—

Abstract

A process and apparatus for oxidizing thiol compounds from an alkaline stream. The process includes passing a thiol rich alkaline stream and an oxygen containing gas to a low pressure oxidizing zone to oxidize at least a portion of the thiol compounds to disulfide compounds. A liquid stream comprising the alkali containing the disulfide compounds is passed through a pump to increase the pressure and form a pressurized alkaline stream. The pressurized alkaline stream and a sulfur lean liquid light hydrocarbon stream are introduced to a high pressure disulfide separation vessel to form a sulfur lean alkaline stream and a sulfur rich liquid light hydrocarbon stream.

First claim

What is claimed:

1 . A process for oxidizing thiol compounds from an alkaline stream comprising:
passing a thiol rich alkaline stream and an oxygen containing gas to a low pressure oxidizing zone to oxidize at least a portion of the thiol compounds to disulfide compounds; passing a liquid stream comprising the alkali containing the disulfide compounds through a pump to increase the pressure of the liquid stream comprising the alkali containing the disulfide compounds and form a pressurized alkaline stream containing the disulfide compounds; and introducing the pressurized alkaline stream containing the disulfide compounds and a sulfur lean liquid light hydrocarbon stream to a high pressure disulfide separation vessel to form a sulfur lean alkaline stream and a sulfur rich liquid light hydrocarbon stream.

2 . The process of claim 1 further comprising separating a non-soluble vapor stream from a liquid stream comprising the alkali containing the disulfide compounds before passing the liquid stream comprising the alkali containing the disulfide compounds through the pump.

3 . The process of claim 1 wherein the sulfur lean liquid light hydrocarbon stream is butane, propane, ethane, liquefied petroleum gas, or combinations thereof.

4 . The process of claim 1 wherein the oxidizing zone is operated at a pressure of about 210 kPa (g) to about 550 kPa (g).

5 . The process of claim 1 wherein the disulfide separation vessel is operated at a pressure of about 690 kPa(g) to about 2760 kPa(g).

6 . The process of claim 1 wherein the disulfide separation vessel has a counter-current flow.

7 . The process of claim 5 wherein the pressurized alkaline stream containing the disulfide compounds is introduced near the top of the disulfide separation vessel, and the sulfur lean liquid light hydrocarbon stream is introduced near the bottom of the disulfide separation vessel.

8 . The process of claim 1 wherein the thiol rich alkaline stream and the oxygen-containing gas are mixed before being passed to the oxidizing zone.

9 . The process of claim 1 wherein the oxygen-containing gas comprises air.

10 . The process of claim 1 wherein a flow rate of the sulfur lean liquid light hydrocarbon stream is about 2 to about 20 vol % of a flow rate of the pressurized oxidized alkaline stream.

11 . The process of claim 1 wherein the oxidizing zone is operated at a temperature of about 38° C. to about 60° C.

12 . The process of claim 1 further comprising heating the thiol rich alkaline stream before passing the thiol rich alkaline stream to the oxidizing zone.

13 . The process if claim 1 wherein the oxidizing zone is an upflow packed bed oxidizing zone.

14 . A process for oxidizing thiol compounds from an alkaline stream comprising:
passing a thiol rich alkaline stream and an oxygen containing gas to a low pressure upflow packed bed oxidizing zone at a pressure of about 210 kPa(g) to about 550 kPa(g) to oxidize at least a portion of the thiol compounds to disulfide compounds; separating a non-soluble vapor stream from a liquid stream comprising the alkali containing the disulfide compounds; passing the liquid stream comprising the alkali containing the disulfide compounds through a pump to increase the pressure of the liquid stream comprising alkali containing the disulfide compounds and form a pressurized alkaline stream containing the disulfide compounds; and introducing the pressurized alkaline stream containing the disulfide compounds and a sulfur lean liquid light hydrocarbon stream to a high pressure counter-current disulfide separation vessel at a pressure of about 690 kPa(g) to about 2760 kPa(g) to form a sulfur lean alkaline stream and a sulfur rich liquid light hydrocarbon stream, wherein the sulfur lean liquid light hydrocarbon stream comprises butane, propane, ethane, liquefied petroleum gas, or combinations thereof.

15 . The process of claim 14 wherein the thiol rich alkaline stream and the oxygen-containing gas are mixed before being passed to the oxidizing zone.

16 . The process of claim 14 wherein a flow rate of the liquid light hydrocarbon stream is about 2 to about 20 vol % of a flow rate the pressurized alkaline stream containing the disulfide compounds.

17 . The process of claim 14 wherein the sulfur lean liquid light hydrocarbon stream is butane, propane, ethane, liquefied petroleum gas, or combinations thereof.

18 . An apparatus comprising:
a low pressure oxidizing zone having an inlet, and a liquid outlet; a pump having an inlet and an outlet, the pump inlet in fluid communication with the oxidizing zone liquid outlet; and a high pressure counter-current disulfide separation vessel having an alkali inlet near the top of the disulfide separation vessel, an alkali outlet at the bottom of the disulfide separation vessel, a wash oil inlet near the bottom of the disulfide separation vessel, and a wash oil outlet at the top of the disulfide separation vessel, the alkali inlet in fluid communication with the pump outlet.

19 . The apparatus of claim 18 wherein the oxidizing zone inlet is in fluid communication with a sulfur rich alkali outlet of an extraction zone, and wherein the alkali outlet of the disulfide separation vessel is in fluid communication with a sulfur lean alkali inlet of the extraction zone.

20 . The apparatus of claim 18 wherein the wash oil inlet is in fluid communication with a source of liquid light hydrocarbon.

Assignees

• Uop Llc

Inventors

• Laricchia Luigi
• Smith Edward F
• Tertel Jonathan A

Classifications

• C07C319/28

  Separation; Purification · CPC title

• C10G70/04

  by physical processes · CPC title

• C10G19/00

  Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment · CPC title

• B01J19/24

  Stationary reactors without moving elements inside (B01J19/08, B01J19/26 take precedence; with stationary particles B01J8/02) · CPC title

• C07C319/24 Primary

  by reactions involving the formation of sulfur-to-sulfur bonds · CPC title