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

Technical Report · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5649596

Jozewicz, W; Chang, J C.S.; Sedman, C B

The paper gives results of an evaluation of calcium sorbents for acid gas emission control for effectiveness in removing SO{sub 2}/HCl and SO{sub 2}/NO{sub x} from simulated incinerator and boiler flue gases. All tests were conducted in a bench-scale fixed-bed reactor 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{sub x} removal was found at 90 C 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.

• Research Organization: Acurex Corp., Research Triangle Park, NC (United States)
• OSTI ID: 5649596
• Report Number(s): PB-91-191445/XAB; CNN: EPA-68-02-4701
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ACTIVATION ENERGY
ADDITIVES
ADSORBENTS
AIR POLLUTION CONTROL
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BENCH-SCALE EXPERIMENTS
BOILERS
CALCIUM COMPOUNDS
CALCIUM HYDROXIDES
CALCIUM SILICATES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINE COMPOUNDS
CONTROL
DENITRIFICATION
DESULFURIZATION
DISPERSIONS
ENERGY
FABRIC FILTERS
FILTERS
FLUE GAS
GASEOUS WASTES
HALOGEN COMPOUNDS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
HYDROXIDES
INCINERATORS
INORGANIC ACIDS
MAGNESIUM COMPOUNDS
MAGNESIUM HYDROXIDES
MIXTURES
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PHOSPHATES
PHOSPHORUS COMPOUNDS
POLLUTION CONTROL
REMOVAL
SILICATES
SILICON COMPOUNDS
SODIUM COMPOUNDS
SODIUM PHOSPHATES
SORPTIVE PROPERTIES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SURFACE PROPERTIES
TESTING
WASTES