Separation of Carbon Dioxide (Co2) From Gas Mixtures By Calcium Based Reaction Separation (Cars-Co2) Process

• US 20080233029A1
• Filed: 06/28/2006
• Published: 09/25/2008
• Est. Priority Date: 02/06/2003
• Status: Active Grant

• Current Assignee: Ohio State University
• Original Assignee: Ohio State University
• Inventors: Gupta, Himanshu, Fan, Liang-Shih, Iyer, Mahesh V.
• Granted Patent: US 8,226,917 B2
• Time in Patent Office: Days
• US Class Current: 423/244.09
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2253/10 Inorganic adsorbents
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/508 by treating the gases with solids
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28071 being less than 0.5 ml/g
• CPC Class Codes: B01J 20/3085 Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
• CPC Class Codes: B01J 20/3433 of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3466 with steam
• CPC Class Codes: B01J 20/3483 by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: B01J 8/06 in tube reactors; the solid particles being arranged in tubes
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01F 11/06 of carbonates
• CPC Class Codes: C01P 2002/32 spinel-type (AB2O4)
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2006/12 : Surface area
• CPC Class Codes: C01P 2006/14 : Pore volume
• CPC Class Codes: C01P 2006/17 : Pore diameter distribution
• CPC Class Codes: C10J 2300/0996 : Calcium-containing inorganic materials, e.g. lime
• CPC Class Codes: C10J 2300/1807 : Recycle loops, e.g. gas, solids, heating medium, water
• CPC Class Codes: C10J 3/482 : Gasifiers with stationary fluidised bed
• CPC Class Codes: C10K 1/024 : by filtration
• CPC Class Codes: C10K 3/04 : reducing the carbon monoxide content , e.g. water-gas shift [WGS]
• CPC Class Codes: H01M 2008/1293 : Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 8/0668 : Removal of carbon monoxide or carbon dioxide
• 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

Abstract

A reaction-based process has been developed for the selective removal of carbon dioxide (CO₂) from a multicomponent gas mixture to provide a gaseous stream depleted in CO2 compared to the inlet CO₂ concentration in the stream. The proposed process effects the separation of CO₂ from a mixture of gases (such as flue gas/fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO₂ (CaRS—CO₂) process consists of contacting a CO₂ laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO₂ by the formation of calcium carbonate (CaCOa). Once “spent”, CaCO₃ is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO₂. The “regenerated” CaO is then recycled for the further capture of more CO₂. This carbonation-calcination cycle forms the basis of the CaRS—CO₂ process. This process also identifies the application of a mesoporous CaCO₃ structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles.

Claims

1-20. -20. (canceled)

21. A method for separating carbon dioxide and sulfur dioxide from a flow of gas comprising carbon dioxide and sulfur dioxide, said method comprising the steps of:

(a) directing said flow of gas to a gas-solid contact reactor, said gas-solid contact reactor containing a sorbent comprising a metal oxide;

(b) reacting said carbon dioxide and said sulfur dioxide with said sorbent so as to convert at least a portion of said sorbent to a metal carbonate and at least a portion of said sorbent to a metal sulfate;

(c) directing at least a portion of said metal carbonate to a calcinator;

(d) calcining said metal carbonate so as to form said metal oxide and carbon dioxide; and

(e) replenishing said sorbent in said gas-solid reactor with said metal oxide formed in said calcinator.