Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

• US 9,174,844 B2
• Filed: 05/13/2013
• Issued: 11/03/2015
• Est. Priority Date: 10/13/2008
• Status: Active Grant

• Current Assignee: The Ohio State University Research Foundation
• Original Assignee: The Ohio State University Research Foundation
• Inventors: Ramkumar, Shwetha, Fan, Liang-Shih
• Primary Examiner(s): Mayes, Melvin C
• Assistant Examiner(s): CALL, DOUGLAS BRYANT
• Application Number:
  US13/892,681
• Publication Number:
  US 20140158939A1
• Time in Patent Office: 904 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B01D 2253/112 Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106
• CPC Class Codes: B01D 2256/16 Hydrogen
• CPC Class Codes: B01D 2257/204 Inorganic halogen compounds
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/10 with dispersed adsorbents
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/043 Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration
• CPC Class Codes: C01B 2203/0465 Composition of the impurity
• CPC Class Codes: C01B 2203/047 the impurity being carbon monoxide
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/0485 the impurity being a sulfur compound
• CPC Class Codes: C01B 2203/062 Hydrocarbon production, e.g. Fischer-Tropsch process
• CPC Class Codes: C01B 2203/0827 at least part of the fuel being a recycle stream
• CPC Class Codes: C01B 2203/148 involving a recycle stream to the feed of the process for making hydrogen or synthesis gas
• CPC Class Codes: C01B 2203/82 Several process steps of C01B2203/02 - C01B2203/08 integrated into a single apparatus
• CPC Class Codes: C01B 2203/84 Energy production
• CPC Class Codes: C01B 2203/86 Carbon dioxide sequestration
• CPC Class Codes: C01B 3/344 using non-catalytic solid particles
• CPC Class Codes: C01B 3/48 : followed by reaction of water vapour with carbon monoxide
• CPC Class Codes: C01B 3/583 : the reaction being the selective oxidation of carbon monoxide
• CPC Class Codes: C10G 2300/1022 : Fischer-Tropsch products
• CPC Class Codes: C10J 2300/1612 : CO2-separation and sequestration, i.e. long time storage
• CPC Class Codes: C10J 2300/1646 : integrated with a fuel cell
• CPC Class Codes: C10J 2300/1653 : integrated in a gasification combined cycle [IGCC]
• CPC Class Codes: C10J 2300/1659 : to liquid hydrocarbons
• CPC Class Codes: C10J 3/54 : Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
• CPC Class Codes: C10K 1/003 : of acid contaminants, e.g. acid gas removal
• CPC Class Codes: C10K 1/004 : Sulfur containing contaminants, e.g. hydrogen sulfide
• CPC Class Codes: C10K 3/04 : reducing the carbon monoxide content , e.g. water-gas shift [WGS]
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y02E 20/16 : Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
• CPC Class Codes: Y02E 20/18 : Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS]
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 30/00 : Technologies relating to oil refining and petrochemical industry

Abstract

A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H₂S, COS, and HX, wherein X is a halide; (ii) 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 CO₂, sulfur and halides in a solid-phase calcium-containing product comprising CaCO₃, CaS and CaX₂; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) 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 CO₂, in the presence of synthesis gas, in the presence of H₂ and O₂, under partial vacuum, and combinations thereof.

Claims

1. A process for producing hydrogen, comprising the steps of:

reforming in a reforming unit a gaseous hydrocarbon fuel in the presence of calcium oxide and steam to remove carbon dioxide, sulfur and halide contaminants that are present in the form of H₂S, COS and HX, wherein X is a halide, thereby forming a solid-phase calcium-containing product comprising CaCO₃, CaS and CaX₂, and producing a mixture of carbon monoxide and hydrogen;

separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product;

regenerating the calcium oxide to produce a calcined sorbent 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 carbon dioxide, in the presence of synthesis gas, in the presence of hydrogen and oxygen, under partial vacuum, and combinations thereof;

reactivating the calcined sorbent by hydrating it in the presence of steam or water or a mixture of both; and

injecting the hydrated sorbent into the reforming unit.

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 reformer, so as to introduce a chemical species selected from the group consisting of;

methane, C1-C4 hydrocarbons, carbon dioxide, hydrogen and combinations thereof back into the reformer.

3. The process of claim 2 wherein the reforming step is conducted in the presence of a catalyst.

4. The process of claim 1 wherein the 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.

5. The process of claim 1 wherein the calcium oxide has a sorption capacity of at least 30 grams of carbon dioxide per kilogram of calcium oxide for 5 cycles and higher.

6. The process of claim 1, comprising of a fixed fluidized bed of catalyst particles with the calcium sorbent entrained through the system.

7. The process of claim 1 wherein the heat produced by the exothermic production of CaCO₃ from carbon dioxide and calcium oxide is used for the endothermic reforming step.

8. The process of claim 1 wherein the reforming step is conducted in the presence of a reforming or prereforming catalyst.

9. The process of claim 8 wherein the catalyst is selected from the group consisting of:

Ni, Pt, Rh, Pd, Ru, W, Mo, their oxides, their carbides and their sulfides.

10. The process of claim 8 wherein the calcium oxide is mixed with the reforming or a prereforming catalyst and the hydrogen is produced at a temperature in the range of 550-750°

C., and a pressure in the range of 1-60 atmospheres.

11. The process of claim 10, wherein the pressure is in the range of from 20 to 30 atmospheres.

12. The process of claim 10, wherein the temperature is in the range of 600-700°

C.

13. The process of claim 12, wherein the pressure is in the range of from 20 to 30 atmospheres.