High purity, high pressure hydrogen production with in-situ CO
A process for producing hydrogen, comprising the steps of: (a) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam and sulfur and halide contaminants in the form of H 2 S, COS and HX, where X is a halide; (b) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO 2 , sulfur and halides in a solid-phase calcium-containing product comprising CaCO 3 , CaS and CaX 2 ; (c) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (d) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO 2 , in the presence of synthesis gas, in the presence of H 2 and O 2 , under partial vacuum, and combinations thereof. The CaO may have a surface area of at least 12.0 m2/g and a pore volume of at least 0.015 cm3/g, the CaO having a sorption capacity of at least about 70 grams of CO2 per kilogram of CaO.
1. A process for producing hydrogen, comprising the steps of:
gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam and sulfur and halide contaminants in the form of H 2 S, COS and HX, where X is a halide;
injecting said raw synthesis gas, CaO and steam simultaneously into a water gas shift reactor (WGSR) wherein said raw synthesis gas transforms into a shifted gas;
allowing said shifted gas to react with said CaO in said water gas shift reactor so as to remove sulfur and halides in a solid-phase calcium-containing product comprising CaCO 3 , CaS and CaX 2 ;
separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and
regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO 2 , in the presence of synthesis gas, in the presence of H 2 and O 2 , under partial vacuum, and combinations thereof.
2. The process of claim 1 additionally comprising the step of:
recycling at least a portion of a product stream from a Fischer-Tropsch reactor, fed by the WGSR, so as to introduce a chemical species selected from the group consisting of: methane, C1-C4 hydrocarbons, CO, hydrogen and combinations thereof back into the WGSR.
3. The process of claim 1 wherein said WSGR has disposed therein a catalyst.
4. The process of claim 3 wherein said catalyst includes a material selected from the group consisting of: Fe, Cu, Co, Mo, W, Cs, Pt, Ph, Pd, other precious metal catalysts, oxides thereof, sulfides thereof, and combinations thereof.
5. The process of claim 2 wherein said WSGR has disposed therein a catalyst.
6. The process of claim 1 wherein said enriched hydrogen product has a purity in the range of from about 70% to about 99.99% H2, a temperature in the range of from about 400 to about 1000 C, and a pressure in the range of from about 1 to about 100 atmosphere.
7. The process of claim 1 wherein said CaO has a surface area of at least 12.0 m2/g and a pore volume of at least 0.015 cm3/g, said CaO having a sorption capacity of at least about 70 grams of CO2 per kilogram of CaO.
8. The process of claim 2 wherein said CaO has a surface area of at least 12.0 m2/g and a pore volume of at least 0.015 cm3/g, said CaO having a sorption capacity of at least about 70 grams of CO2 per kilogram of CaO.
9. A process for producing hydrogen, comprising the steps of:
reforming a gaseous hydrocarbon fuel in the presence of CaO and steam to remove CO2, sulfur and halide contaminants in the form of H 2 S, COS and HX, where X is a halide, in a solid-phase calcium-containing product comprising CaCO 3 , CaS and CaX 2 , thereby producing a mixture of CO and hydrogen;
separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and
regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO 2 , in the presence of synthesis gas, in the presence of H 2 and O 2 , under partial vacuum, and combinations thereof.
10. The process of claim 9 additionally comprising the step of:
recycling at least a portion of a product stream from a Fischer-Tropsch reactor, fed by the reformer, so as to introduce a chemical species selected from the group consisting of: methane, C1-C4 hydrocarbons, CO, hydrogen and combinations thereof back into the reformer.
11. The process of claim 9 wherein said reforming step is conducted in the presence of a catalyst.
12. The process of claim 11 wherein said catalyst is selected from the group consisting of: Ni, Pt, Rh, Pd, Ru, W, Mo, oxide thereof, carbides thereof, and sulfides thereof.
13. The process of claim 10 wherein said reforming step is conducted in the presence of a catalyst.
14. The process of claim 9 wherein said enriched hydrogen product has a purity in the range of from about 70% to about 99.99% H2, a temperature in the range of from about 400 to about 1000 C, and a pressure in the range of from about 1 to about 100 atmosphere.
15. The process of claim 9 wherein said CaO has a surface area of at least 12.0 m2/g and a pore volume of at least 0.015 cm3/g, said CaO having a sorption capacity of at least about 70 grams of CO2 per kilogram of CaO.
16. The process of claim 10 wherein said CaO has a surface area of at least 12.0 m2/g and a pore volume of at least 0.015 cm3/g, said CaO having a sorption capacity of at least about 70 grams of CO2 per kilogram of CaO.
17. A process for producing hydrogen, comprising the steps of:
at least partially oxidizing a fuel into a raw gas comprising CO, hydrogen, steam and sulfur and halide contaminants in the form of H 2 S, COS and HX, where X is a halide;
injecting said raw synthesis gas, CaO and steam simultaneously into a water gas shift reactor (WGSR) wherein said raw synthesis gas transforms into a shifted gas;
allowing said shifted gas to react with said CaO in said water gas shift reactor so as to remove sulfur and halides in a solid-phase calcium-containing product comprising CaCO 3 , CaS and CaX 2 ;
separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and
regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO 2 , in the presence of synthesis gas, in the presence of H 2 and O 2 , under partial vacuum, and combinations thereof.
18. The process of claim 17 wherein said WSGR has disposed therein a catalyst.
19. The process of claim 18 wherein said catalyst includes a material selected from the group consisting of: Fe, Cu, Co, Mo, W, Cs, Pt, Ph, Pd, other precious metal catalysts, oxides thereof, sulfides thereof, and combinations thereof.
20. The process of claim 17 wherein said enriched hydrogen product has a purity in the range of from about 70% to about 99.99% H2, a temperature in the range of from about 400 to about 1000 C, and a pressure in the range of from about 1 to about 100 atmosphere.
21. The process of claim 17 wherein said CaO has a surface area of at least 12.0 m2/g and a pore volume of at least 0.015 cm3/g, said CaO having a sorption capacity of at least about 70 grams of CO2 per kilogram of CaO.