Bench-scale evaluation of calcium sorbents for acid gas emission control

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Environmental Progress; (USA)

DOI:https://doi.org/10.1002/ep.670090312· OSTI ID:5497071

Jozewicz, W; Chang, J C.S. ^[1]; Sedman, C B ^[2]

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1. Acurex Corp., Research Triangle Park, NC (USA)
2. Environmental Protection Agency, Research Triangle Park, NC (USA)

Calcium sorbents for acid gas emission control were evaluated for effectiveness in removing SO{sub 2}/HCl and SO{sub 2}/NO from simulated incinerator and boiler flue gases. All tests were conducted in a bench-scale reactor (fixed-bed) simulating fabric filter conditions in an acid gas removal process. Reagent grade Ca(OH){sub 2} was used to establish baseline sorbent performance. The reactivity of reagent grade Ca(OH){sub 2} with HCl from SO{sub 2}/HCl mixtures gradually increased with decreasing approach to saturation temperature. SO{sub 2} reactivity toward Ca(OH){sub 2} was very sensitive to approach to saturation. Novel calcium silicate sorbents were tested for reactivity with both SO{sub 2} and HCl. A thermal window for optimum NO removal was found at 90{degree}C (194{degree}F) when Ca(OH){sub 2} was used at SO{sub 2}/NO ratios of 1:1. Reactivity of Ca(OH){sub 2} toward SO{sub 2} from SO{sub 2}/NO mixtures was very sensitive to approach to saturation, while reactivity with NO was insensitive. Several additives were subsequently tested to determine optimum sorbent combinations for SO{sub 2}/NO control. To date the most promising additives are Mg(OH){sub 2} and Na{sub 2}HPO{sub 4} at 10 mol% concentrations. As with SO{sub 2}/HCl, calcium silicate has been shown to be superior for SO{sub 2}/NO capture. Some implications for larger-scale process configurations and sorbent selection for HCl/SO{sub 2}/NO control are discussed. Future activities and limited larger-scale pilot plant results are also discussed.

• OSTI ID: 5497071
• Journal Information: Environmental Progress; (USA), Journal Name: Environmental Progress; (USA) Vol. 9:3; ISSN ENVPD; ISSN 0278-4491
• Country of Publication: United States
• Language: English

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