HIGH PRESSURE REDUCTION-OXIDATION DESULFURIZATION PROCESS

• US 20120107205A1
• Filed: 10/27/2010
• Published: 05/03/2012
• Est. Priority Date: 10/27/2010
• Status: Active Grant

• Current Assignee: Merichem Company
• Original Assignee: Merichem Company
• Inventors: Nagl, Gary J.
• Granted Patent: US 8,372,365 B2
• Time in Patent Office: Days
• US Class Current: 423/224
• CPC Class Codes: B01D 2251/102 Oxygen
• CPC Class Codes: B01D 2251/30 Alkali metal compounds
• CPC Class Codes: B01D 2251/90 Chelants
• CPC Class Codes: B01D 2251/902 EDTA
• CPC Class Codes: B01D 2251/904 NTA
• CPC Class Codes: B01D 2255/20738 Iron
• CPC Class Codes: B01D 2256/245 Methane
• CPC Class Codes: B01D 2258/02 Other waste gases
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1468 Removing hydrogen sulfide
• CPC Class Codes: B01D 53/8612 Hydrogen sulfide
• CPC Class Codes: C07C 7/11 by absorption, i.e. purification or separation of gaseous hydrocarbons with the aid of liquids

Abstract

An improved process for reduction-oxidation desulphurization uses an oxidizer operating at a pressure greater than the absorber where a liquid reduction-oxidation catalyst solution contacts a sulfur-containing gas feed stream.

Claims

1. A process for continuously removing hydrogen sulfide from a gaseous stream comprising the following steps in combination:

a. providing a feed stream containing hydrogen sulfide to an reduction-oxidation process;

b. contacting the feed gas stream with a chelated metal catalyst in an absorber operating a pressure P1 that is greater than 100 psig to produce a first stream of hydrogen sulfide-free gas and a second stream comprising elemental sulfur and chelated metal catalyst solution;

c. removing the first stream from the process;

d. providing an oxidizer operating a pressure P2, where P2≧

P1+5 psi;

e. directing at least a portion of the second stream from step b. to the oxidizer;

f. introducing a pressurized, oxygen containing gas stream into the oxidizer such that the oxygen diffuses through and contacts the second stream; and

g. separating elemental sulfur from the chelated metal catalyst solution in the oxidizer and removing the sulfur from the reduction-oxidation process.

2. The process of claim 1 where the oxygen containing gas is introduced into the oxidizer at a pressure P3, where P3≧

P2.

3. The process of claim 1 where the oxygen containing gas introduced into the oxidizer is used to maintain the pressure differential between the oxidizer and the absorber.

4. The process of claim 1 further comprising the absence of a flash drum in fluid communication with the absorber and the oxidizer.

5. The process of claim 1 where the oxidizer pressure P1 is maintained by the combination of high pressure air injection and a differential pressure controller that monitors the absorber pressure P2 and operates a pressure control valve on an oxidizer vent line.