US 8,206,669 B2Granted

Method and apparatus for treating a sour gas

AssigneeAir Products and Chemicals, Inc.

InventorsCharles Linford Schaffer, Andrew David Wright, Kevin Boyle Fogash, Jeffrey William Kloosterman, Vincent White

Life of this patent

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Abstract

A feed gas comprising CO2, H2S and H2 is treated to produce an H2-enriched product and a CO2 product. The feed gas is separated by pressure swing adsorption to provide a stream of the H2-enriched product, and two streams of sour gas depleted in H2 and enriched in H2S and CO2 relative to the feed gas. One of the streams of sour gas is processed in an H2S to elemental sulfur conversion system, in which H2S in the sour gas is converted to elemental sulfur order to obtain a stream of sweetened gas, from which the CO2 product is formed. The other of said streams of sour gas is processed in an oxidation system, in which H2S in the sour gas is oxidized to SOx(SO2 and SO3) which is introduced into the H2S to elemental sulfur conversion system.

Claims28

Dependent claims

A method for treating a feed gas, comprising about 10 to about 65 mole % CO2, about 50 ppm to about 5 mole % H2S and at least about 30 mole % H2, to produce an H2-enriched product and a CO2 product, the method comprising:

separating the feed gas by pressure swing adsorption (PSA) to obtain a stream of H2-enriched product gas and two streams of sour gas, each sour gas stream comprising CO2, H2S and H2 but being depleted in H2 and enriched in H2S and CO2 relative to the feed gas, each sour gas stream containing at least about 5 mole % H2 and at most about 10 mole % H3S;
processing one of said streams of sour gas in an H2S to elemental sulfur conversion system by contacting the sour gas with SO2, sulfuric acid and/or sulfurous acid to convert H2S to elemental sulfur and form a stream of sweetened gas, said sweetened gas being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
processing the other of said streams of sour gas in an oxidation system by oxidizing at least about 90% of H2S and at least about 90% of the H2 in the sour gas via reaction with O2 to produce heat and form an oxidation effluent, said effluent comprising CO2, SOx (SO2 and SO3) and H2O and being enriched in CO2 and depleted in H2S and H2 relative to the feed gas, and:
(i) introducing into the H2S to elemental sulfur conversion system at least a portion of the SO2 obtained from the oxidation system, so as to provide at least a portion of said SO2 for reaction with H2S in the H2S to elemental sulfur conversion system;
and/or (ii) converting at least a portion of the SOx obtained from the oxidation system to sulfuric and/or sulfurous acid, and introducing at least a portion of said acid into the H2S to elemental sulfur conversion system to provide at least a portion of said acid for reaction with H2S in the H2S to elemental sulfur conversion system;
and
forming the CO2 product from said stream of sweetened gas obtained from the H2S to elemental sulfur conversion system.

4 more elements

An apparatus for treating a feed gas, comprising CO2, H2S and H2, to produce an H2-enriched product and a CO2 product, the apparatus comprising:

a pressure swing adsorption (PSA) system for separating the feed gas to obtain a stream of H2-enriched product gas and two streams of sour gas, each sour gas stream comprising CO2, H2S and H2 but being depleted in H2 and enriched in H2S and CO2 relative to the feed gas;
an oxidation system for processing one of said streams of sour gas by oxidizing at least about 90% of the H2S and at least about 90% of the H2 in the sour gas via reaction with O2 to produce heat and form an oxidation effluent, said effluent comprising CO2, SOx (SO2 and SO3) and H2O and being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
an H2S to elemental sulfur conversion system for processing the other of said streams of sour gas by contacting the sour gas with SO2 to convert H2S to elemental sulfur and form a stream of sweetened gas, said sweetened gas being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
conduit means for transferring said streams of sour gas from the PSA system to the oxidation and H2S to elemental sulfur conversion systems;
a heat exchanger for recovering heat from the oxidation effluent via indirect heat exchange;
conduit means for withdrawing oxidation effluent from the oxidation system, passing the effluent through the heat exchanger, and introducing at least a portion thereof into the H2S to elemental sulfur conversion system to provide SO2 for reaction with H2S;
and
conduit means for withdrawing the stream of sweetened gas from the H2S to elemental sulfur conversion system, the CO2 product being formed from said stream.

5 more elements

An apparatus for treating a feed gas, comprising CO2, H2S and H2, to produce an H2-enriched product and a CO2 product, the apparatus comprising:

a pressure swing adsorption (PSA) system for separating the feed gas to obtain a stream of H2-enriched product gas and two streams of sour gas, each sour gas stream comprising CO2, H2S and H2 but being depleted in H2 and enriched in H2S and CO2 relative to the feed gas;
an oxidation system for processing one of said streams of sour gas by oxidizing at least about 90% of the H2S and at least about 90% of the H2 in the sour gas via reaction with O2 to produce heat and form an oxidation effluent, said effluent comprising CO2, SOx (SO2 and SO3) and H2O and being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
an SO2/CO2 separation system for separating the oxidation effluent to form an SO2-enriched stream and an SO2-depleted oxidation effluent;
an H2S to elemental sulfur conversion system for processing the other of said streams of sour gas by contacting the sour gas with SO2 to convert H2S to elemental sulfur and form a stream of sweetened gas, said sweetened gas being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
conduit means for transferring said streams of sour gas from the PSA system to the oxidation and H2S to elemental sulfur conversion systems;
a heat exchanger for recovering heat from the oxidation effluent via indirect heat exchange;
conduit means for withdrawing oxidation effluent from the oxidation system, passing the effluent through the heat exchanger, and introducing the effluent into the SO2/CO2 separation system;
conduit means for transferring the SO2-enriched stream from the SO2/CO2 separation system to the H2S to elemental sulfur conversion system to provide SO2 for reaction with H2S;
and
conduit means for withdrawing the stream of sweetened gas from the H2S to elemental sulfur conversion system, the CO2 product being formed from said stream.

7 more elements

An apparatus for treating a feed gas, comprising CO2, H2S and H2, to produce an H2-enriched product and a CO2 product, the apparatus comprising:

a pressure swing adsorption (PSA) system for separating the feed gas to obtain a stream of H2-enriched product gas and two streams of sour gas, each sour gas stream comprising CO2, H2S and H2 but being depleted in H2 and enriched in H2S and CO2 relative to the feed gas;
an oxidation system for processing one of said streams of sour gas by oxidizing at least about 90% of the H2S and at least about 90% of the H2 in the sour gas via reaction with O2 to produce heat and form an oxidation effluent, said effluent comprising CO2, SOx (SO2 and SO3) and H2O and being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
a SOx to acid conversion system for converting SOx in the oxidation effluent to sulfuric and/or sulfurous acid and separating said acid from the effluent to form an SOx-depleted oxidation effluent;
an H2S to elemental sulfur conversion system for processing the other of said streams of sour gas by contacting the sour gas with sulfuric and/or sulfurous acid to convert H2S to elemental sulfur and form a stream of sweetened gas, said sweetened gas being enriched in CO2 and depleted in H2S and H2 relative to the feed gas;
conduit means for transferring said streams of sour gas from the PSA system to the oxidation and H2S to elemental sulfur conversion systems;
a heat exchanger for recovering heat from the oxidation effluent via indirect heat exchange;
conduit means for withdrawing oxidation effluent from the oxidation system, passing the effluent through the heat exchanger, and introducing the effluent into the SOx to acid conversion system;
conduit means for transferring sulfuric and/or sulfurous acid from the SOx to acid conversion system to the H2S to elemental sulfur conversion system to provide sulfuric and/or sulfurous acid for reaction with H2S;
and
conduit means for withdrawing the stream of sweetened gas from the H2S to elemental sulfur conversion system, the CO2 product being formed from said stream.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/844,034Filed 27 Jul 2010
Published: US 2012/0027656 A12 Feb 2012
Granted: 26 Jun 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification20 codes

C01B 3/56
Separation of hydrogen or hydrogen-containing gases from gaseous mixtures, e.g. purification: by contacting with solids; Regeneration of used solids
B01D 53/047
With stationary adsorbents: pressure swing adsorption
C01B 3/34
By reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide or air: by reaction of hydrocarbons with…
C01B 17/0404
From gaseous sulfur compounds including gaseous sulfides: by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases,…