Sulfur recovery unit

Patent metadata

Field	Value
Publication number	US-9556030-B2
Application number	US-201414535428-A
Country	US
Kind code	B2
Filing date	Nov 7, 2014
Priority date	Nov 8, 2013
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A sulfur recovery unit for processing an acid gas feed to recover elemental sulfur, the sulfur recovery unit comprising a reaction furnace configured to burn the acid gas feed, an oxygen source, and a fuel gas to create a furnace outlet stream, the acid gas feed comprises hydrogen sulfide which is converted to elemental sulfur, a waste heat boiler configured to capture heat from the furnace outlet stream to create a cooled stream, a condenser configured to condense the cooled stream to produce a waste gas stream and a condensed stream comprising elemental sulfur, a thermal oxidizer configured to burn the waste gas stream to create a sulfur dioxide rich stream, and a sulfur dioxide scrubbing unit configured to remove the amount of sulfur dioxide from the sulfur dioxide rich stream to create an effluent stream and a recycle stream recycled to the reaction furnace.

First claim

What is claimed is:

1. A sulfur recovery unit for processing an acid gas feed to recover elemental sulfur, the sulfur recovery unit comprising:
a reaction furnace, the reaction furnace configured to burn the acid gas feed, an oxygen source, and a fuel gas to create a furnace outlet stream, the reaction furnace comprises a main burner and a reaction chamber, the main burner is configured to heat the acid gas feed, the oxygen source, and the fuel gas to a minimum reaction temperature,
wherein the minimum reaction temperature is between 1000° C. and 1250° C.,
wherein the acid gas feed comprises hydrogen sulfide,
wherein the hydrogen sulfide is converted to the elemental sulfur in the reaction chamber;

a waste heat boiler fluidly connected to the reaction furnace, the waste heat boiler configured to capture heat from the furnace outlet stream to create a cooled stream,
wherein the heat captured from the furnace outlet stream is operable to heat a water feed to create steam;

a condenser fluidly connected to the waste heat boiler, the condenser configured to condense the cooled stream to produce a waste gas stream and a condensed stream,
wherein the waste gas stream comprises sulfur-containing contaminants, and
wherein the condensed stream comprises the elemental sulfur;

a thermal oxidizer fluidly connected to the condenser, the thermal oxidizer configured to burn the waste gas stream, the oxygen source, and the fuel gas to create a sulfur dioxide rich stream,
wherein a conversion of the sulfur-containing contaminants to sulfur dioxide is operable to occur in the thermal oxidizer,
wherein the sulfur dioxide rich stream comprises the sulfur dioxide; and

a sulfur dioxide scrubbing unit fluidly connected to the thermal oxidizer, the sulfur dioxide scrubbing unit configured to remove an amount of sulfur dioxide from the sulfur dioxide rich stream to create an effluent stream and a recycle stream, the recycle stream comprising the amount of sulfur dioxide,
wherein the recycle stream is recycled to the reaction furnace.

2. The sulfur recovery unit of claim 1 , wherein the oxygen source is selected from the group consisting of air, oxygen enriched air, and pure oxygen.

3. The sulfur recovery unit of claim 1 , wherein the cooled stream is at a temperature of 300° C.

4. The sulfur recovery unit of claim 1 , wherein a temperature of the waste gas stream is between 125° C. and 150° C.

5. The sulfur recovery unit of claim 1 , wherein the oxygen source provides a stoichiometric excess of oxygen in the thermal oxidizer, wherein the stoichiometric excess of oxygen promotes the conversion of the sulfur-containing contaminants to the sulfur dioxide.

6. The sulfur recovery unit of claim 1 , wherein the amount of sulfur dioxide is greater than 99.9% by volume of the recycle stream.

7. The sulfur recovery unit of claim 1 , wherein the recycle stream provides a stoichiometric ratio in the reaction furnace of the hydrogen sulfide to the sulfur dioxide of 2:1.

8. A sulfur recovery process to recover elemental sulfur from an acid gas feed, the sulfur recovery process comprising the steps of:
feeding the acid gas feed, an oxygen source, and a fuel gas to a main burner of a reaction furnace, the main burner configured to heat the acid gas feed, the oxygen source, and a fuel gas source to a minimum reaction temperature, the acid gas feed having hydrogen sulfide, wherein the minimum reaction temperature is between 1000° C. and 1250° C.;
converting the acid gas feed, the oxygen source, and the fuel gas at the minimum reaction temperature to create a furnace outlet stream, wherein the furnace outlet stream comprises the elemental sulfur and sulfur-containing contaminants;
recovering heat from the furnace outlet stream in a waste heat boiler to create a cooled stream, the waste heat boiler configured to capture heat from the furnace outlet stream to heat a water feed to create steam;
condensing the cooled stream in a condenser to produce a condensed stream and a waste gas stream, the condensed stream comprising the elemental sulfur, the waste gas stream comprising the sulfur-containing contaminants;
combusting the waste gas stream, the oxygen source, and the fuel gas in a thermal oxidizer to create a sulfur dioxide rich stream, the sulfur dioxide rich stream comprising sulfur dioxide, wherein a conversion of the sulfur-containing contaminants in the waste gas stream to the sulfur dioxide is operable to occur;
feeding the sulfur dioxide rich stream to a sulfur dioxide scrubbing unit, the sulfur dioxide scrubbing unit configured to remove an amount of sulfur dioxide from the sulfur dioxide rich stream to create a recycle stream and an effluent stream, wherein the recycle stream comprises the amount of sulfur dioxide; and
recycling the recycle stream to the main burner of the reaction furnace.

9. The sulfur recovery process of claim 8 , wherein the oxygen source is selected from the group consisting of air, oxygen enriched air, and pure oxygen.

10. The sulfur recovery process of claim 8 , wherein the cooled stream is at a temperature of 300° C.

11. The sulfur recovery process of claim 8 , wherein a temperature of the waste gas stream is between 125° C. and 150° C.

12. The sulfur recovery process of claim 8 , wherein the oxygen source provides a stoichiometric excess of oxygen in the thermal oxidizer, wherein the stoichiometric excess of oxygen promotes the conversion of the sulfur-containing contaminants to the sulfur dioxide.

13. The sulfur recovery process of claim 8 , wherein the amount of sulfur dioxide is greater than 99.9% by volume of the recycle stream.

14. The sulfur recovery process of claim 8 , wherein the recycle stream provides a stoichiometric ratio in the reaction furnace of the hydrogen sulfide to the sulfur dioxide of 2:1.

15. A sulfur recovery unit for processing an acid gas feed to recover elemental sulfur, the sulfur recovery unit consisting essentially of:
a reaction furnace, the reaction furnace configured to burn the acid gas feed, an oxygen source, and a fuel gas to create a furnace outlet stream, the reaction furnace comprises a main burner and a reaction chamber, the main burner is configured to heat the acid gas feed, the oxygen source, and the fuel gas to a minimum reaction temperature,
wherein the minimum reaction temperature is between 1000° C. and 1250° C.,
wherein the acid gas feed comprises hydrogen sulfide,
wherein the hydrogen sulfide is converted to the elemental sulfur in the reaction chamber;

a waste heat boiler fluidly connected to the reaction furnace, the waste heat boiler configured to capture heat from the furnace outlet stream to create a cooled stream,
wherein the heat captured from the furnace outlet stream is operable to heat a water feed to create steam;

a condenser fluidly connected to the waste heat boiler, the condenser configured to condense the cooled stream to produce a waste gas stream and a condensed stream,
wherein the waste gas stream comprises sulfur-containing contaminants, and
wherein the condensed stream comprises the elemental sulfur;

a thermal oxidizer fluidly connected to the condenser, the thermal oxidizer configured to burn the waste gas stream, the oxygen source, and the fuel gas to create a sulfur dioxide rich stream,
wherein a conversion of the sulfur-containing contaminants to sulfur dioxide is operable to occur in the thermal oxidizer,
wherein the sulfur dioxide rich stream comprises the sulfur dioxide; and

a sulfur dioxide scrubbing unit fluidly connected to the thermal oxidizer, the sulfur dioxide scrubbing unit configured to remove an am

Assignees

• Saudi Arabian Oil Co

Inventors

• O'Connell John P

Classifications

• B01D2257/304

  Hydrogen sulfide · CPC title

• B01J2219/24

  Stationary reactors without moving elements inside · CPC title

• C01B17/0456 Primary

  the hydrogen sulfide-containing gas being a Claus process tail gas · CPC title

• C01B17/04

  from gaseous sulfur compounds including gaseous sulfides · CPC title

• B01J19/245

  placed in series · CPC title