LT: Heterogeneous Catalysis in Supercritical Carbon Dioxide

9873553 Abraham许多商业化学合成是在有机液体溶剂中使用均相催化剂进行的。 大规模使用有机溶剂对环境的长期影响受到质疑。 本研究的目的是探索使用超临界二氧化碳作为一种环境友好的反应溶剂，特别是，其用于丙烯加氢精制。 使用CO2作为反应溶剂提供了最佳的环境性能，因为CO2不会消耗臭氧层，不会导致地面烟雾，也不会导致全球变暖。由于溶解度的限制，目前的均相催化剂不太可能充分溶解以在CO2中有效。 提出了使用多相催化，并且通过消除催化回收步骤并允许反应在简单的填充床反应器中进行，这也将简化下游操作。 为了证明聚丙烯的加氢精制可以在超临界CO2中完成，并且基于该技术的方法与现有技术相比在环境上是上级的并且在经济上是有竞争力的，研究人员将（1）制备已成功用于气相加氢多相催化剂，并测试这些催化剂在超临界二氧化碳中的活性，和（2）确定CO2对反应机理的影响及其在控制产物选择性和丙烯转化率方面的作用。 该补助金是根据1998年NSF/朗讯科技工业生态学研究奖学金计划联合颁发的。

9873553 Abraham Many commercial chemical syntheses are carried out in organic liquid solvents using homogeneous catalysts. The large-scale use of organic solvents has been questioned with respect to long-term environmental impacts. The objective of this research is to explore the use of supercritical carbon dioxide as an environmentally benign reaction solvent, and in particular, its use for the hydroformylation of propylene. The use of CO2 as a reaction solvent offers optimal environmental performance because CO2 does not deplete the ozone layer, does not contribute to ground level smog and will not contribute to global warming. Because of solubility limitations, it is unlikely that current homogeneous catalysts can be made sufficiently soluble to be effective in CO2. The use of a heterogeneous catalysis is proposed and that will also simplify the downstream operations by eliminating the catalysis recovery step and allowing the reaction to be performed in a simple packed bed reactor. In order to demonstrate that hydroformylation of polypropylene can be accomplished in supercritical CO2 and that a process based on this technology is environmentally superior and economically competitive with current technology, the researcher will (1) prepare selected heterogeneous catalysts that have successfully been used for vapor phase hydroformylation and test these catalysts for their activity in supercritical carbon dioxide and (2) determine the impact of CO2 on the reaction mechanism and its role in controlling the product selectivity and the rate of propylene conversion. This grant is made pursuant to the joint NSF/Lucent Technologies Industrial Ecology Research Fellowships Program 1998.***