CO{sub 2} capture capacity of CaO in long series of carbonation/calcination cycles
- CSIC, Zaragoza (Spain)
Calcium oxide can be an effective sorbent to separate CO{sub 2} at high temperatures. When coupled with a calcination step to produce pure CO{sub 2}, the carbonation reaction is the basis for several high-temperature CO{sub 2} capture systems. The evolution with cycling of the capture capacity of CaO derived from natural limestones is experimentally investigated in this work. Long series of carbonation/calcination cycles (up to 500) varying different variables affecting sorbent capacity have been tested in a thermogravimetric apparatus. Calcination temperatures above T > 950{sup o}C and very long calcination times accelerate the decay in sorption capacity, while other variables have a comparatively modest effect on the overall sorbent performance. A residual conversion of about 7-8% that remains constant after many hundreds of cycles and that seems insensitive to process conditions has been found. This residual conversion makes very attractive the carbonation/calcination cycle, by reducing (or even eliminating) sorbent purge rates in the system. A semiempirical equation has been proposed to describe sorbent conversion with the number of cycles based on these new long data series.
- OSTI ID:
- 20847714
- Journal Information:
- Industrial and Engineering Chemistry Research, Vol. 45, Issue 26; ISSN 0888-5885
- Country of Publication:
- United States
- Language:
- English
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