# US 10,246,329 B1 · Extended thermal stage sulfur recovery process

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,246,329 B1
- Document ID: US10246329B1
- Status: Granted
- Kind: B1
- Application number: 15/815,980
- Filed: 2017-11-17
- Granted: 2019-04-02
- Earliest claimed: 2017-11-17
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: John P. O'Connell
- Web page: https://patentgrep.com/patent/US10246329B1

## CPC

- C01B 17/0426: {characterised by the catalytic conversion}
- B01D 53/1481: {Removing sulfur dioxide or sulfur trioxide}
- B01D 53/52: Hydrogen sulfide
- B01D 53/523: {Mixtures of hydrogen sulfide and sulfur oxides}
- B01J 12/007: {in the presence of catalytically active bodies, e.g. porous plates}
- B01J 19/0013: {Controlling the temperature of the process}
- B01J 19/0053: {Details of the reactor}
- C01B 17/0404: {by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process}
- C01B 17/16: Hydrogen sulfides
- C01B 17/508: {by oxidation of sulfur compounds}
- B01D 2257/302: Sulfur oxides
- B01D 2257/304: Hydrogen sulfide
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

A process for recovering sulfur in a sulfur recovery unit comprising the steps of reacting hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent; reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants; reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent; reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream; reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream comprises sulfur dioxide; and separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, the recycle stream comprises sulfur dioxide.

## Claims

### Claim 1

A process for recovering sulfur in a sulfur recovery unit, the process comprising the steps of:
introducing an acid gas feed to a reaction furnace, where the acid gas feed comprises hydrogen sulfide;
introducing a fuel gas to the reaction furnace;
introducing air feed to the reaction furnace, where the air feed comprises oxygen;
reacting the hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent, where the reaction effluent comprises elemental sulfur and sulfur dioxide, where the reaction effluent is at the minimum reaction temperature;
introducing the reaction effluent to a wasteheat stage of an extended boiler stage;
reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, where the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants, where the temperature of the reaction effluent is reduced by capturing heat energy;
introducing the cooled effluent to a catalytic extension of the extended boiler stage, where the catalytic extension comprises a catalyst, where the catalytic extension has a gross hourly space velocity between 3000 h−1 and 6000 h−1;
reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent, where the boiler catalytic effluent comprises elemental sulfur, where the boiler catalytic effluent is at a boiler catalytic effluent temperature;
introducing the boiler catalytic effluent to a condenser, where the boiler catalytic effluent comprises elemental sulfur;
reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream;
introducing the gases stream to a thermal oxidizer, where the gases stream comprises hydrogen sulfide and sulfur-containing contaminants;
introducing an air stream to the thermal oxidizer, where the air stream comprises oxygen;
reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream, where the oxidizer outlet stream comprises sulfur dioxide;
introducing the oxidizer outlet stream to a scrubbing unit; and
separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, where the recycle stream comprises sulfur dioxide.

### Claim 2 (depends on 1)

The process of claim 1, further comprises the step of introducing the recycle stream to the reaction furnace.

### Claim 3 (depends on 1)

The process of claim 1, further comprises the steps of:
introducing a boiler feed water to the extended boiler stage; and
increasing the temperature of the boiler feed water to produce a high pressure steam, where the heat captured from the reaction effluent is used to increase the temperature of the boiler feed water.

### Claim 4 (depends on 1)

The process of claim 1, where the minimum reaction temperature is between 850 deg C. and 1250 deg C.

### Claim 5 (depends on 1)

The process of claim 1, where the boiler section outlet temperature is between 148 deg C. and 254 deg C.

### Claim 6 (depends on 1)

The process of claim 1, where the boiler catalytic effluent temperature is between 250 deg C. and 400 deg C.

### Claim 7 (depends on 1)

The process of claim 1, where the catalyst is titania extrudate.

### Claim 8 (depends on 1)

The process of claim 1, where an overall conversion of sulfur compounds to elemental sulfur is greater than 99.9 mol %.

### Claim 9 (depends on 1)

The process of claim 1, further comprising the steps of:
analyzing a composition of the gases stream in a tail gas analyzer; and
adjusting a flow rate of the air feed based on the composition of the gases stream to maintain a stoichiometric ratio of hydrogen sulfide to sulfur dioxide of 2:1.

### Claim 10 (depends on 1)

The process of claim 1, further comprising the steps of:
measuring the minimum reaction temperature in the reaction furnace with a temperature sensor; and
adjusting a flow rate of the fuel gas to maintain the minimum reaction temperature.