霍夫曼烷基化反應(yīng)反應(yīng)機(jī)理

苯烯比是烷基化反應(yīng)中重要的調(diào)節(jié)參數(shù),其值直接影響產(chǎn)品的質(zhì)量與收率。從原理上分析了高苯烯比的必要性,并經(jīng)生產(chǎn)實踐將苯烯比定為8:1。在此基礎(chǔ)上,根據(jù)影響苯烯比的主要因素,對生產(chǎn)工藝進(jìn)行了改造,將實際苯烯比調(diào)整到合適值。改造達(dá)到了工業(yè)生產(chǎn)要求,取得了較好的經(jīng)濟(jì)效益。

Shape selective alkylation of polynuclear aromatics has begun to receive increasing attention. 2,6 dialkylnaphthalenes are important raw materials for manufacturing high quality polyester fibers and plastics. Understanding of the reaction and the catalysis for conversion of polycyclic aromatic hydrocarbons is needed both from fundamental and practical view points. In this paper, alkylation of naphthalene with propene over a series of dealuminated mordenite with different Si/Al ratios was carried out in an autoclave with an electromagnetical stirrer. Textural property of the dealuminated mordenite was determined by nitrogen adsorption. The amount of the acid sites was measured by NH 3 TPD. The catalytic activity of HM and β shape selectivity for products increased with increasing the Si/Al ratio in HM. Moreover, the selectivity for alkylation with propene was also increased by dealumination treatment. The increase of the catalytic activity was attributed to the formation of mesopores, which significantly promoted the diffusion of reactants and products in mordenite. It was suggested that the increase of β selectivity resulted from the elimination of acid sites from the external surface, and the selectivity for alkylation with propene was improved owing to the creation of the interconnection between 12 ring and 8 rimg channels by dealumination.