共查询到19条相似文献,搜索用时 125 毫秒
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胶束催化合成环氧丙烷的清洁生产技术 总被引:2,自引:0,他引:2
介绍了国外在环氧丙烷清洁生产技术领域的新研究进展:环氧丙烷胶束催化氧化技术,包括胶束催化的机理、胶束催化体系设计以及工艺开发。胶束催化体系更适合于设计原位分离反应工艺,以表面活性剂、催化剂、助催化剂为主的胶束催化体系设计是胶束催化技术的关键。指出开发清洁经济的环氧丙烷生产技术是环氧丙烷工业持续发展的关键,建议加强环氧丙烷胶束催化技术的研究及相关工艺开发。 相似文献
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丙烯氧气氧化制环氧丙烷工艺开发进展 总被引:4,自引:0,他引:4
以分子氧为氧源的丙烯环氧化反应是近年来发展起来的一种清洁型环氧丙烷合成技术。综述了丙烯氧气氧化工艺的开发背景、开发进展及其经济性。丙烯与O2氧化工艺以及丙烯与O2、H2氧化工艺因反应过程和反应机理不同而采用相异的催化剂和工艺条件,虽然丙烯氧气氧化工艺存在产率低、生产成本高的缺点,但作为具有最佳原子经济性和较低投资费用的新工艺路线,具有工业化应用前景。 相似文献
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The gas-phase epoxidation of propylene using N2O, air and air-ammonia mixture as an oxidants was studied. Propylene can be epoxidized by nitrous oxide with a yield as high
as 13.3% over silica supported iron oxide catalysts modified by amines. The iron oxide dispersion, the acidity of the support
and the nitrogen-containing modifiers are the key factors determining the catalytic performance. We suggest a reaction pathway
involving two concurrent mechanisms: the radical oxidation of propylene to acroleine, hexanediene, etc., and a non-radical
oxidation leading to epoxide. Propylene is epoxidized with air over silica-supported iron oxide catalysts at a conversion
of about 0.2%. Using air as an oxidizing agent, the presence of gaseous ammonia improves the propylene conversion by 10-fold
preserving the considerable selectivity (up to 60%). This observation suggests a reaction mechanism involving the oxidation
of ammonia to nitrous oxide in the first step, which subsequently produces active oxygen species, which selectively oxidize
propylene to propylene oxide (PO). 相似文献
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<正>(上接2007年第5期)3.4脱水-氢化工艺使回收PO后的反应液中的CMA先在催化剂存在下脱水转化成α-甲基苯乙烯,然后在氢化催化剂存在下,使α-甲基苯乙烯氢化为CM。 相似文献
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环氧丙烷生产的技术进展 总被引:1,自引:0,他引:1
分析环氧丙烷生产技术发展趋势:氯醇法对环境不友好,虽仍在改进,最终难免被淘汰;环氧丙烷联产苯乙烯或叔丁醇法因苯乙烯叔丁醇有市场需求产能正在扩大,但因对原料要求高而受到限制;预测过氧化氢氧化工艺将会加快工业化。 相似文献
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Oxidation Catalysis by Supported Gold Nano-Clusters 总被引:4,自引:0,他引:4
The historical notion regarding the inability of gold to catalyze reactions has been discarded in view of recent studies, which have clearly demonstrated the high catalytic efficiency of supported nano-gold catalysts. Although nano-Au catalysts are known to catalyze a variety of reactions, the major focus has been on CO oxidation catalysis. In this work we focus on the important aspects related to the CO oxidation reaction. Special emphasis is placed on the studies undertaken on model nano-Au systems as these studies have considerably enhanced the understanding of the oxidation process. Gold in a highly dispersed state can selectively oxidize CO in the presence of excess hydrogen (of tremendous interest to state-of-the-art low-temperature fuel cells); related studies are addressed in this review. The nano-gold catalysts have also been investigated for the direct vapor-phase oxidation of propylene to propylene oxide in the presence of molecular oxygen; these investigations are highlighted in this work. 相似文献
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丙烯选择性氧化制丙烯醛的催化剂研究 总被引:2,自引:0,他引:2
选择和制备了多种过渡金属单氧化物和复合氧化物催化剂。采用微反-色谱联用装置研究了它们对丙烯氧化制丙烯醛的催化性能。分别考察了反应温度、气体空速、原料配比的影响;其中所研制的金属原子比为2:3:1的Fe-V-Ti复合氧化物催化剂,在空速为10000h~(-1),反应温度为320℃,C3H6/O2=1:1的条件下,丙烯转化率为78%,丙烯醛选择性为95%,收率为74%,时空产率为5000g·L~(-1)·h~(-1)。 相似文献
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固体强碱绿色催化环氧丙烷水解合成1,2-丙二醇 总被引:3,自引:1,他引:2
该文制备了不同碱强度的固体碱催化剂,并应用于环氧丙烷(PO)水解合成1,2-丙二醇的反应。结果表明:随着催化剂碱强度的增加,环氧丙烷的转化率不断升高;说明强碱催化剂有利于环氧丙烷水解反应。在此基础上,作者系统考察了催化剂用量、反应温度、原料摩尔比和反应时间对催化性能的影响。结果表明:当催化剂CaO-ZrO2质量为反应原料质量的1.0%,反应温度为120℃,反应原料配比为:n(H2O)∶n(PO)=5∶1,反应时间2h时,其催化效果较优,环氧丙烷转化率最高为92.3%,1,2-丙二醇选择性可达89.4%。 相似文献