Low Temperature Catalytic Oxidation of Hydrogen Sulfide and Methanethiol Using Wood and Coal Fly Ash
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- 作者：James R. Kastner ; K. C. Das ; Quentin Buquoi ; and Nathan D. Melear
- 刊名：Environmental Science & Technology
- 出版年：2003
- 出版时间：June 1, 2003
- 年：2003
- 卷：37
- 期：11
- 页码：2568 - 2574
- 全文大小：116K
- 年卷期：v.37,no.11(June 1, 2003)
- ISSN：1520-5851
文摘
The feasibility of reusing waste material as an inexpensivecatalyst to remove sulfur compounds from gaseouswaste streams has been demonstrated. Wood and coalfly ash were demonstrated to catalytically oxidize H2S andmethanethiol (CH3SH) at low temperatures (23-25 
C).Wood ash had a significantly higher surface area comparedto coal ash (44.9 vs 7.7 m2/g), resulting in a higher initialH2S removal rate (0.16 vs 0.018 mg/g/min) under similarconditions. Elemental sulfur was determined to be the endproduct of H2S oxidation, since X-ray diffraction analysisindicated the presence of crystalline sulfur. Catalytic decayoccurred apparently due to surface deposition of sulfurand a subsequent decline in surface area (44.9-1.4 m2/g)during the reaction of H2S with the ash. Methanethiolwas stoichiometrically converted to dimethyl disulfide((CH3)2S2) without significant catalytic decay. Catalyticdecay was reduced and H2S conversion increased (10%at 1.8 days vs 94% at 4.2 days) when H2S loading wasdecreased to levels typical of many environmental applications(500 ppmv inlet and 1.43 mg/min vs 60 ppmv, 0.09 mg/min). Catalyst regeneration using hot water (85 C) washingwas possible, but only increased fractional conversionfrom 0.2 to 0.6 and the initial reaction rate to 50% of theoriginal H2S oxidation activity.
C).Wood ash had a significantly higher surface area comparedto coal ash (44.9 vs 7.7 m2/g), resulting in a higher initialH2S removal rate (0.16 vs 0.018 mg/g/min) under similarconditions. Elemental sulfur was determined to be the endproduct of H2S oxidation, since X-ray diffraction analysisindicated the presence of crystalline sulfur. Catalytic decayoccurred apparently due to surface deposition of sulfurand a subsequent decline in surface area (44.9-1.4 m2/g)during the reaction of H2S with the ash. Methanethiolwas stoichiometrically converted to dimethyl disulfide((CH3)2S2) without significant catalytic decay. Catalyticdecay was reduced and H2S conversion increased (10%at 1.8 days vs 94% at 4.2 days) when H2S loading wasdecreased to levels typical of many environmental applications(500 ppmv inlet and 1.43 mg/min vs 60 ppmv, 0.09 mg/min). Catalyst regeneration using hot water (85 C) washingwas possible, but only increased fractional conversionfrom 0.2 to 0.6 and the initial reaction rate to 50% of theoriginal H2S oxidation activity.