Claus unit treatment of shutdown tail gas

Patent metadata

Field	Value
Publication number	US-10188988-B2
Application number	US-201715449010-A
Country	US
Kind code	B2
Filing date	Mar 3, 2017
Priority date	Mar 23, 2016
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

The process for configuring or reconfiguring a sulfur removal plant having a plurality of Claus units that is greater than the number of downstream tail gas treating units (TGTUs) allows for the regeneration of one of the Claus units without shutting down any of the downstream TGTUs or the other Claus units. Specifically, the regeneration tail gas can be diverted to the reaction furnace of an in-service Claus unit, thereby allowing excess oxygen to be used to regenerate the Claus unit more efficiently, and without exceeding environmental SO2 emission requirements.

First claim

The invention claimed is:

1. A method for regenerating a Claus unit in a sulfur removal complex comprising a plurality of Claus units and a smaller number of tail gas treating units (TGTUs), the method comprising the steps of:
(a) switching a feed to a regenerating Claus unit's reaction furnace to natural gas;
(b) combusting the natural gas in the reaction furnace using an approximately stoichiometric amount of oxygen;
(c) sending tail gas from the regenerating Claus unit to an in-service TGTU;
(d) once liquid sulfur is no longer produced from the regenerating Claus unit in step (b), sending the tail gas to an in-service Claus unit's reaction furnace; and
(e) adding excess oxygen to the regenerating Claus unit's reaction furnace.

2. The method of claim 1 , wherein the excess oxygen is increased incrementally up to about 10%.

3. The method of claim 1 , further comprising:
(f) once the tail gas from the regenerating Claus unit after step (e) contains an environmentally acceptable concentration of sulfur, sending the tail gas to an incinerator.

4. The method of claim 1 , wherein the tail gas in step (d) is sent to the combustion air piping for the in-service Claus unit's reaction furnace.

5. The method of claim 1 , wherein the tail gas in step (d) is sent to the air plenum for the in-service Claus unit's reaction furnace.

6. The method of claim 1 , wherein the tail gas in step (d) is sent to a dedicated nozzle on the in-service Claus unit's reaction furnace.

7. A method for regenerating a single Claus unit in a sulfur removal complex comprising a plurality of Claus units and a smaller number of tail gas treating units (TGTUs), the method comprising the steps of:
combusting natural gas in a regenerating Claus units' reaction furnace with excess oxygen; and
sending resulting tail gas to an in-service Claus unit's reaction furnace;
wherein no other Claus unit or TGTU is shut down during the regeneration of the single Claus unit.

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Debrock Matt E
• Colwell James F
• Richard Megan M
• Gislain Jon F
• Corley John D

Classifications

• C01B17/0452

  Process control; Start-up or cooling-down procedures of the Claus process · CPC title

• B01D53/8603

  Removing sulfur compounds · CPC title

• B01D53/8612

  Hydrogen sulfide · CPC title

• C01B17/0447

  Separation of the obtained sulfur · CPC title

• B01D53/96 Primary

  Regeneration, reactivation or recycling of reactants · CPC title