Sintering and reactivity of CaCO{sub 3}-based sorbents for in situ CO{sub 2} capture in fluidized beds under realistic calcination conditions
- Natural Resources Canada, Ottawa, ON (Canada)
Sintering during calcination/carbonation may introduce substantial economic penalties for a CO{sub 2} looping cycle using limestone/dolomite-derived sorbents. Cyclic carbonation and calcination reactions were investigated for CO{sub 2} capture under fluidized bed combustion (FBC) conditions. The cyclic carbonation characteristics of CaCO{sub 3}-derived sorbents were compared at various calcination temperatures (700-925{sup o} C) and different gas stream compositions: pure -2 and a realistic calciner environment where high concentrations of CO{sub 2}>80-90% are expected. The conditions during carbonation were 700 {sup o}C and 15% CO{sub 2} in N{sub 2} and 0.18% or 0.50% SO{sub 2} in selected tests. Up to 20 calcination/carbonation cycles were conducted using a thermogravimetric analyzer (TGA) apparatus. Three Canadian limestones were tested: Kelly Rock, Havelock, and Cadomin, using a prescreened particle size range of 400-650 {mu} m. Calcined Kelly Rock and Cadomin samples were hydrated by steam and examined. Sorbent reactivity was reduced whenever SO{sub 2} was introduced to either the calcining or carbonation streams. The multicyclic capture capacity of CaO for CO{sub 2} was substantially reduced at high concentrations of CO{sub 2} during the sorbent regeneration process and carbonation conversion of the Kelly Rock sample obtained after 20 cycles was only 10.5%. Hydrated sorbents performed better for CO{sub 2} capture but showed deterioration following calcination in high CO{sub 2} gas streams indicating that high CO{sub 2} and SO{sub 2} levels in the gas stream lead to lower CaO conversion because of enhanced sintering and irreversible formation of CaSO{sub 4}.
- OSTI ID:
- 21198013
- Journal Information:
- Journal of Environmental Engineering (New York), Journal Name: Journal of Environmental Engineering (New York) Journal Issue: 6 Vol. 135; ISSN 0733-9372; ISSN JOEEDU
- Country of Publication:
- United States
- Language:
- English
Similar Records
SO{sub 2} retention by reactivated CaO-based sorbent from multiple CO{sub 2} capture cycles
CO{sub 2} capture from simulated syngas via cyclic carbonation/calcination for a naturally occurring limestone: pilot-plant testing