碳纤维材料的性能与应用.ppt

Some research Discovery research aimed at identifying a 100%-selective active site is ongoing both in industry and in academia. An example: a catalyst that decreases by-product pollutant CCl4 selectivity during the manufacture of phosgene has been recently discovered. The conventional coconut carbon-based catalyst produced about 500 ppm of CCl4 in the exhaust, which had to be reduced to below 100 ppm to meet the tighter regulations. The new catalyst has reduced CCl4 levels to below 50 ppm and produces more phosgene Computational chemistry is being increasingly used to probe the active site. There is a need for tools that represent and track molecular species in complex feeds. This is especially true in petroleum refining. Molecular modeling is being used to estimate transport coefficients in zeolites (Theodorou et al., 1996). There is a continuing need to extend the work to more complex feed and catalyst systems. Process technology for the on-site manufacture and immediate use of hazardous chemicals eliminates the need to transport, store and handle hazardous chemicals. An alternate approach to on-site generation is to develop technology that renders materials non-hazardous prior to shipping. An example: used in the delivery of HCN to mine sites for gold extraction, is to reduce the risk of exposure by converting HCN to solid NaCN prior to shipment. There is an active interest in finding new uses for by-products or converting by-products to useful products. Volatile organic compound (VOC) control The two primary options for destroying VOCs are by thermal or catalytic oxidation. Thermal oxidizers (combustion devices): achieve high destruction efficiency if properly operated at the 3Ts: temperature, turbulence, and residence time. Catalytic oxidizers may be bead beds or monoliths. The active catalytic ingredients (usually noble metals) are typically supported on a high surface area alumina (Spivey, 1987). Catalytic systems can typically opera