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Title: Efficient recovery of carbon dioxide from flue gases of coal-fired power plants by cyclic fixed-bed operations over K{sub 2}CO{sub 3}-on-carbon

An efficient chemical absorption method capable of cyclic fixed-bed operations under moist conditions for the recovery of carbon dioxide from flue gases has been proposed employing K{sub 2}CO{sub 3}-on-carbon. Carbon dioxide was chemically absorbed by the reaction K{sub 2}CO{sub 3} + CO{sub 2} + H{sub 2}O {r_equilibrium} 2KHCO{sub 3} to form potassium hydrogen carbonate. Moisture, usually contained as high as 8--17% in flue gases, badly affects the capacity of conventional adsorbents such as zeolites, but the present technology has no concern with moisture; water is rather necessary in principle as shown in the equation above. Deliquescent potassium carbonate should be supported on an appropriate porous material to adapt for fixed-bed operations. After breakthrough of carbon dioxide, the entrapped carbon dioxide was released by the decomposition of hydrogen carbonate to shift the reaction in reverse on flushing with steam, which could be condensed by cooling to afford carbon dioxide in high purity. Among various preparations of alkaline-earth carbonates (X{sub 2}CO{sub 3}, X = Li, Na, K) on porous materials, K{sub 2}CO{sub 3}-on-activated carbon revealed excellent properties for the present purpose. Preparation and characterization of K{sub 2}CO{sub 3}-on-carbon and illustrative fixed-bed operations under flue gas conditions in laboratory columns and a bench-scalemore » plant are described.« less
Authors:
; ; ;  [1] ; ; ;  [2]
  1. Univ. of Tokushima (Japan). Dept. of Chemical Science and Technology
  2. Shikoku Research Inst., Inc., Takamatsu (Japan)
Publication Date:
OSTI Identifier:
599782
Resource Type:
Journal Article
Resource Relation:
Journal Name: Industrial and Engineering Chemistry Research; Journal Volume: 37; Journal Issue: 1; Other Information: PBD: Jan 1998
Country of Publication:
United States
Language:
English
Subject:
20 FOSSIL-FUELED POWER PLANTS; 01 COAL, LIGNITE, AND PEAT; CARBON DIOXIDE; CHEMISORPTION; FOSSIL-FUEL POWER PLANTS; FLUE GAS; POTASSIUM CARBONATES; COAL; MOISTURE; MATERIALS RECOVERY; ACTIVATED CARBON; AIR POLLUTION CONTROL