SO{sub 2} retention by reactivated CaO-based sorbent from multiple CO{sub 2} capture cycles

Journal Article · Fri Jun 15 00:00:00 EDT 2007 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es0629458· OSTI ID:20923840

Manovic, Vasilije; Anthony, Edward J ^[1]

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1. CANMET Energy Technology Centre-Ottawa, Ottawa, ON (Canada). Natural Resources Canada

This paper examines the reactivation of spent sorbent, produced from multiple CO{sub 2} capture cycles, for use in SO{sub 2} capture. CaO-based sorbent samples were obtained from Kelly Rock limestone using three particle size ranges, each containing different impurities levels. Using a thermogravimetric analyzer (TGA), the sulfation behavior of partially sulfated and unsulfated samples obtained after multiple calcination-carbonation cycles in a tube furnace (TF), following steam reactivation in a pressurized reactor, is examined. In addition, samples calcined/sintered under different conditions after hydration are also examined. The results show that suitably treated spent sorbent has better sulfation characteristics than that of the original sorbent. Thus for example, after 2 h sulfation, {gt} 80% of the CaO was sulfated. In addition, the sorbent showed significant activity even after 4 h when {gt} 95% CaO was sulfated. The results were confirmed by X-ray diffraction (XRD) analysis, which showed that, by the end of the sulfation process, samples contained CaSO{sub 4} with only traces of unreacted CaO. The superior behavior of spent reactivated sorbent appears to be due to swelling of the sorbent particles during steam hydration. The surface area morphology of sorbent after reactivation was examined by scanning electron microscopy (SEM). Ca(OH){sub 2} crystals were seen, which displayed their regular shape, and their elemental composition was confirmed by energy-dispersive X-ray (EDX) analysis. These results allow the proposal of a new process for the use of CaO-based sorbent in fluidized bed combustion (FBC) systems, which incorporates CO{sub 2} capture, sorbent reactivation, and SO{sub 2} retention. 26 refs., 4 figs., 2 tabs.

• OSTI ID: 20923840
• Journal Information: Environmental Science and Technology, Vol. 41, Issue 12; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
SULFUR DIOXIDE
ADSORBENTS
CALCIUM OXIDES
CAPTURE
CARBON DIOXIDE
SULFATION
RETENTION
REGENERATION
MORPHOLOGY
ADSORPTION ISOTHERMS
PARTICLE SIZE
CALCINATION
RECYCLING
ADSORPTION
FLUIDIZED-BED COMBUSTION
HYDRATION
THERMAL GRAVIMETRIC ANALYSIS
LIMESTONE
WASTE PRODUCT UTILIZATION
STEAM
SWELLING
SURFACE AREA
PORE STRUCTURE