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US 8,557,218 B2Granted
Hydrogen production with carbon capture
AssigneeExxonMobil Research and Engineering Company
InventorsNarasimhan Sundaram, John W. Viets
Life of this patent
Estimating the term…
Abstract
Systems and methods for hydrogen production with carbon capture are provided. A hydrogen containing stream can be divided so that a portion of the stream is processed for separation of CO2. A hydrogen enriched stream formed during separation of CO2 and another portion of the hydrogen containing stream can be processed in a cycling adsorber unit to form a hydrogen product stream. Optionally, the cycling adsorber unit can be operated to form a plurality of tail gas streams. The hydrogen containing stream can be a reformed hydrocarbon stream and/or an input stream previously exposed to a water gas shift catalyst. Optionally, a portion of the reformed hydrocarbon stream can be a reformed biocomponent stream.
Claims13
A method for recovery of hydrogen and CO2 in a refinery, comprising:
- dividing an input stream containing hydrogen, carbon dioxide, and a hydrocarbon into a first input portion and a second input portion, the input stream comprising an effluent from a reforming unit, the input stream exhibiting a hydrogen content of at least about 70 vol % and a CO2 content of at least about 5 vol %, the first input portion comprising from about 5 vol % to about 60 vol % of the input stream;
- combining the first input portion and a first tail gas stream, the combined first input portion and first tail gas stream exhibiting a CO2 content of less than about 70 vol %;
- separating the first input portion and a first tail gas stream to form a CO2 recovery stream and a hydrogen enriched stream, the CO2 recovery stream having a CO2 content of at least about 70 vol %, the CO2 recovery stream containing at least about 80% of the CO2 in the combined first input portion and first tail gas stream;
- exposing the hydrogen enriched stream and the second input portion to an adsorbent in a cycling adsorber unit at a pressure of at least about 500 psig (about 3.4 MPag) to produce a hydrogen product stream having a hydrogen content of at least about 90 vol %, the hydrogen product stream containing at least about 85% of the hydrogen in the input stream;
- contacting the adsorbent with a first regeneration stream at a first pressure of about 45 psig (about 310 kPag) to about 130 psig (about 900 kPag) to form the first tail gas stream, the first tail gas stream containing a first combined content of CO plus CO2 of at least about 60 vol % on a dry basis and a first hydrocarbon content of about 10 vol % or less on a dry basis;
- contacting the adsorbent with a second regeneration stream at a second pressure of about 5 psig (about 35 kPag) to about 20 psig (about 140 kPag) to form a second tail gas stream, the second tail gas stream containing a second combined content of CO plus CO2 of about 10 vol % or less on a dry basis and a second hydrocarbon content of at least about 40 vol % on a dry basis, the second tail gas stream comprising from about 25% to about 60% of a combined volume of the first and second tail gas streams;
- and
- introducing the second tail gas stream as an input to the reforming unit.
5 more elements
A method for recovery of hydrogen and CO2 in a refinery, comprising:
- dividing an input stream containing hydrogen, carbon dioxide, and a hydrocarbon into a first input portion and a second input portion, the input stream comprising an effluent from a reforming unit, the input stream exhibiting a hydrogen content from about 40 vol % to about 70 vol % and a CO2 content of at least about 25 vol %, the first input portion comprising from about 5 vol % to about 60 vol % of the input stream;
- combining the first input portion and a first tail gas stream, the combined first input portion and first tail gas stream having a CO2 content of less than about 70 vol %;
- separating the first input portion and a first tail gas stream to form a CO2 recovery stream and a hydrogen enriched stream, the CO2 recovery stream having a CO2 content of at least about 70 vol %, the CO2 recovery stream containing at least about 80% of the CO2 in the combined first input portion and first tail gas stream;
- exposing the hydrogen enriched stream and the second input portion to an adsorbent in a cycling adsorber unit at a pressure of at least about 500 psig (about 3.4 MPag) to produce a hydrogen product stream having a hydrogen content of at least about 90 vol %, the hydrogen product stream containing at least about 85% of the hydrogen in the input stream;
- contacting the adsorbent with a first regeneration stream at a first pressure of about 45 psig (about 310 kPag) to about 130 psig (about 900 kPag) to form the first tail gas stream, the first tail gas stream containing a first combined content of CO plus CO2 of at least about 50 vol % on a dry basis and a first hydrocarbon content of about 10 vol % or less on a dry basis;
- contacting the adsorbent with a second regeneration stream at a second pressure from about 5 psig (about 35 kPag) to about 2.0 psig (about 140 kPag) to form a second tail gas stream, the second tail gas stream containing a second combined content of CO plus CO2 of about 10 vol % or less on a dry basis and a second hydrocarbon content of at least about 50 vol % on a dry basis, the second tail gas stream comprising from about 5% to about 25% of a combined volume of the first and second tail gas streams;
- and
- introducing the second tail gas stream as an input to the reforming unit.
5 more elements
Dependencies are inferred from the claim text.