Kastner James R, Das K C, Buquoi Quentin, Melear Nathan D
Department of Biological and Agricultural Engineering, Driftmier Engineering Center, The University of Georgia, Athens, Georgia 30602, USA.
Environ Sci Technol. 2003 Jun 1;37(11):2568-74. doi: 10.1021/es0259988.
The feasibility of reusing waste material as an inexpensive catalyst to remove sulfur compounds from gaseous waste streams has been demonstrated. Wood and coal fly ash were demonstrated to catalytically oxidize H2S and methanethiol (CH3SH) at low temperatures (23-25 degrees C). Wood ash had a significantly higher surface area compared to coal ash (44.9 vs 7.7 m2/g), resulting in a higher initial H2S removal rate (0.16 vs 0.018 mg/g/min) under similar conditions. Elemental sulfur was determined to be the end product of H2S oxidation, since X-ray diffraction analysis indicated the presence of crystalline sulfur. Catalytic decay occurred apparently due to surface deposition of sulfur and a subsequent decline in surface area (44.9-1.4 m2/g) during the reaction of H2S with the ash. Methanethiol was stoichiometrically converted to dimethyl disulfide ((CH3)2S2) without significant catalytic decay. Catalytic decay was reduced and H2S conversion increased (10% at 1.8 days vs 94% at 4.2 days) when H2S loading was decreased 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 degrees C) washing was possible, but only increased fractional conversion from 0.2 to 0.6 and the initial reaction rate to 50% of the original H2S oxidation activity.
已证明将废料作为一种廉价催化剂用于从气态废物流中去除硫化合物的可行性。研究表明，木材和煤飞灰能够在低温（23 - 25摄氏度）下催化氧化硫化氢（H2S）和甲硫醇（CH3SH）。与煤灰相比，木灰具有显著更高的表面积（44.9对7.7平方米/克），这使得在类似条件下木灰对硫化氢的初始去除率更高（0.16对0.018毫克/克/分钟）。由于X射线衍射分析表明存在结晶硫，因此确定元素硫是硫化氢氧化的最终产物。催化衰变显然是由于硫在表面沉积以及在硫化氢与灰分反应过程中表面积随后下降（从44.9平方米/克降至1.4平方米/克）所致。甲硫醇按化学计量转化为二甲基二硫醚（(CH3)2S2），且无明显的催化衰变。当硫化氢负载量降至许多环境应用中的典型水平（入口处500 ppmv和1.43毫克/分钟，而不是60 ppmv、0.09毫克/分钟）时，催化衰变减少，硫化氢转化率提高（1.8天时为10%，4.2天时为94%）。使用热水（85摄氏度）洗涤进行催化剂再生是可行的，但仅将分数转化率从0.2提高到0.6，初始反应速率提高到原始硫化氢氧化活性的50%。
