Integrated production of hydrogen, electricity, and heat
A method and a system for the coproduction of hydrogen, electrical power, and heat energy. An exemplary method includes desulfurizing a feed stream to form a desulfurized feed stream, reforming the desulfurized feed stream to form a methane rich gas, and providing the methane rich gas to a membrane separator. A hydrogen stream is produced in a permeate from the membrane separator. A retentate stream from the membrane separator is provided to a solid oxide fuel cell (SOFC). Electrical power is produced in the SOFC from the retentate stream.
1. A method for coproduction of hydrogen, electrical power, and heat energy, comprising:
desulfurizing a feed stream to form a desulfurized feed stream;
pre-reforming the desulfurized feed stream to form a methane rich gas, wherein the pre-reforming is performed at a steam to carbon ratio (S/C) of about 3 to about 4;
providing the methane rich gas to a membrane separator comprising a water-gas shift catalyst to increase an amount of hydrogen in the methane rich gas, the membrane separator being operated at a temperature between about 300° C. and about 550° C.;
producing a hydrogen stream in a permeate from the membrane separator, wherein the hydrogen is compressed to about 400 bar to about 900 bar and dispensed to a fuel cell vehicle;
providing a retentate stream from the membrane separator to a solid oxide fuel cell (SOFC); and
producing electrical power and heat in the SOFC from the retentate stream.
2. The method of claim 1 , comprising mixing a portion of the hydrogen stream with the feed stream prior to desulfurizing the feed stream.
3. The method of claim 1 , comprising desulfurizing the feed stream in an adsorption unit.
4. The method of claim 1 , comprising heating the retentate stream to an operating temperature for the SOFC prior to providing the retentate stream to the SOFC.
5. The method of claim 1 , comprising utilizing the heat produced in the SOFC.
6. The method of claim 5 , comprising heating the retentate stream with the heat produced in the SOFC.
7. The method of claim 5 , comprising generating steam with the heat produced in the SOFC.
8. The method of claim 1 , wherein the water-gas shift catalyst comprises iron oxides or copper oxides.
9. The method of claim 1 , wherein the pre-reforming is operated at a temperature between about 300° C. and about 550° C.
10. The method of claim 1 , wherein the membrane separator comprises palladium, or a palladium alloy, or both.
11. The method of claim 1 , wherein the membrane separator comprises a carbon-based membrane or a zeolite based membrane.
12. The method of claim 1 , wherein the feed stream comprises propane or butane.
13. The method of claim 1 , wherein the feed stream comprises liquefied natural gas or raw natural gas.
14. A method for coproduction of hydrogen, electrical power, and heat energy, comprising:
desulfurizing a feed stream to form a desulfurized feed stream;
pre-reforming the desulfurized feed stream to form a methane rich gas, wherein the pre-reforming is performed at a steam to carbon ratio (S/C) of about 3 to about 4;
providing the methane rich gas to a membrane separator comprising a water-gas shift catalyst to increase an amount of hydrogen in the methane rich gas, the membrane separator being operated at a temperature between about 300° C. and about 550° C.;
producing a hydrogen stream in a permeate from the membrane separator;
providing a retentate stream from the membrane separator to a solid oxide fuel cell (SOFC); and
producing electrical power and heat in the SOFC from the retentate stream.
15. The method of claim 14 , wherein the hydrogen stream has a hydrogen purity of 80 vol. % or greater, the method further comprising purifying the hydrogen stream.
16. The method of claim 15 , wherein the purifying comprises following the hydrogen stream through a pressure swing adsorption (PSA) system comprising an adsorption column filled with a zeolite absorbent.
17. The method of claim 15 , further comprising compressing the purified hydrogen stream to about 400 bar to about 900 bar.
18. A method for coproduction of hydrogen, electrical power, and heat energy, comprising:
desulfurizing a feed stream to form a desulfurized feed stream;
pre-reforming the desulfurized feed stream to form a methane rich gas, wherein the pre-reforming is performed at a steam to carbon ratio (S/C) of about 3 to about 4;
providing the methane rich gas to a membrane separator comprising a water-gas shift catalyst to increase an amount of hydrogen in the methane rich gas, the membrane separator being operated at a temperature between about 300° C. and about 550° C.;
producing a hydrogen stream in a permeate from the membrane separator;
compressing the hydrogen stream to about 400 bar to about 900 bar;
dispensing the compressed hydrogen stream to a fuel cell vehicle;
providing a retentate stream from the membrane separator to a solid oxide fuel cell (SOFC); and
producing electrical power and heat in the SOFC from the retentate stream.
19. The method of claim 18 , wherein the methane rich gas has a molar ratio of the hydrogen to hydrocarbon between 1:1 and 10:1.
20. The method of claim 18 , further comprising, prior to providing the retentate stream to the SOFC, heating the retentate stream to an operating temperature for the SOFC using the heat produced in the SOFC.