Process for separating synthesis gas into fuel cell quality hydrogen and sequestration ready carbon dioxide

• US 20040061094A1
• Filed: 09/30/2003
• Published: 04/01/2004
• Est. Priority Date: 08/14/2001
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Lyon, Richard K.
• Application Number:
  US10/673,317
• Publication Number:
  US 20040061094A1
• Time in Patent Office: Days
• US Class Current: 252/373
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2251/602 Oxides
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2253/10 Inorganic adsorbents
• CPC Class Codes: B01D 2253/1124 Metal oxides
• CPC Class Codes: B01D 2256/16 Hydrogen
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/502 Carbon monoxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0208 from fuel cells
• CPC Class Codes: B01D 2259/40001 Methods relating to additional, e.g. intermediate, treatment of process gas
• CPC Class Codes: B01D 2259/40081 Counter-current
• CPC Class Codes: B01D 2259/402 using two beds
• CPC Class Codes: B01D 53/08 according to the "moving bed" method
• CPC Class Codes: B01D 53/12 according to the "fluidised technique"
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01J 8/26 with two or more fluidised beds, e.g. reactor and regeneration installations
• CPC Class Codes: C01B 2203/0425 In-situ adsorption process during hydrogen production
• 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 2203/048 : the impurity being an organic compound
• CPC Class Codes: C01B 2203/0485 : the impurity being a sulfur compound
• CPC Class Codes: C01B 2203/86 : Carbon dioxide sequestration
• CPC Class Codes: C01B 3/56 : by contacting with solids; Regeneration of used solids C01B3/508 takes precedence
• CPC Class Codes: C10J 2300/0959 : Oxygen
• CPC Class Codes: C10J 2300/0973 : Water
• CPC Class Codes: C10J 2300/0983 : Additives
• CPC Class Codes: C10J 3/82 : Gas withdrawal means
• CPC Class Codes: H01M 8/0662 : Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y02E 60/50 : Fuel cells
• 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 method and apparatus for separating gas mixtures containing synthesis gas (syngas) into separate streams of wet hydrogen containing significantly reduced amounts of CO₂ and CO, with the CO₂ being “sequestration ready” and containing less than 1% fixed gases. In the preferred embodiment, a mixture of limestone and iron oxide circulates between two fluidized beds whereby one bed is fluidized with a gas containing syngas, while the other bed is fluidized with a gas containing steam and oxygen. As the fluidizing gas containing syngas passes through the bed, the CO₂ reacts with CaO to form CaCO₃. Virtually all of the CO is removed by a water gas shift reaction, forming hydrogen and CO₂, with the remainder being removed by reaction with the iron oxide, reducing Fe₂O₃ to FeO. Some hydrogen is also removed by reaction with the iron oxide, reducing Fe₂O₃ to FeO, while the remainder of the hydrogen passes through the fluid beds, leaving in a purified state, i.e., PEM fuel cell quality.

Claims

1. An apparatus for separating syngas into fuel cell quality hydrogen and sequestration ready carbon dioxide, comprising

first and second fluidized bed reactors containing solids containing calcium compounds present as CaO, Ca(OH)₂ and CaCO₃ and mixtures thereof and iron compounds present as FeO, Fe₃O₄ and Fe₂O₃ and mixtures thereof;

first and second solids transfer lines for circulating said solids mixtures between said first and second fluidized bed reactors;

a first inlet feed for charging said first fluidized bed reactor with high temperature steam and syngas;

a second inlet feed for charging said second fluidized bed reactor with high temperature steam and oxygen;

means for removing substantially pure hydrogen from said first fluidized bed reactor; and

means for removing CO₂ and SO₂ from said second fluidized bed reactor.

2. An apparatus according to claim 11 further comprising steam purge lines in fluid communication with said first and second solids transfer lines.

3. An apparatus according to claim 11 wherein said first fluidized bed reactor is a bubbling reactor or entrained flow reactor

4. An apparatus according to claim 11 wherein said second fluidized bed reactor is a counterflow reactor.

5. An apparatus according to claim 11 wherein a means such as a cyclone or other device for separating solids from fluids is provided at the outlet of said first fluidized bed reactor.