| The separation and purification of cresol through alkylation reaction between cresol and isobutylene is one of important means to obtain high-purity cresol monomers. Dodecyl naphthalene alkylated from dodecene and naphthalene, and dodecylphenol alkylated from dodecene and phenol are two important industrial reaction intermediates. They are not only the important intermediates in modern synthesis of lubricant and anionic surfactant, but also the main ingredients of plasticizers, stabilizers, etc. In order to meet the requirements of contemporary environmental protection, all chemical reactions must take the paths of green and sustainable development. Therefore, environmentally friendly catalysts are highly desired in industry alkylation reactions to replace traditional liquid acid catalyst which causes great pollution, while increasing the reaction catalytic activity, extending the life of catalyst and reducing industrial production costs at the same time. Currently the way to replace the traditional liquid acid is mainly using solid acid materials, but there are some defects such as strict reaction conditions, low conversion rate, short life of the catalyst, and low quality of catalytic product.In this thesis, three types of catalytic materials (strong acid cation exchange resin, HUSY and ultra-stable Y-zeolite package phosphotungstic acid) are studied. We investigate functions of various factors in the process of preparation of catalyst. The catalysts are characterized by FTIR, TG-DSC, BET, XRD, NH3-IR,NH3-TPD to study the properties of solid acid. The catalytic activity of the synthesized solid acid catalyst are evaluated by the alkylation reaction of cresol and isobutylene, dodecene and naphthalene, dodecene and phenol, and the various parameters in the reaction process are systematically investigated in order to improve the conversion rate, product quality, and optimize reaction conditions.The main content and basic conclusions of the study are as follows:1. The results show that strong acid cation exchange resin catalyst has good catalytic activity in the alkylation reaction of cresol and isobutene,dodecene and phenol, but the catalyst life is short; strong acid cation exchange resin has low catalytic activity in the alkylation reaction of dodecene and naphthalene.2. The results show that it gets a better catalytic activity HUSY sieve to alkylate with nitrate concentration of 0.5 mol/L, the ion exchange temperature 353 K, calcination temperature 773 K,4-hour-calcination. HUSY sieve cresol and isobutylene, dodecene and naphthalene, dodecene and phenol catalytic activity of a strong acid cation exchange resin is good, and its activity was significantly decreased after reused for 5 times.3.With BET, FT-IR, NH3-TPD, XRD, SEM and other characterizations, results indicate that USY supercages realize tungstophosphoric acid synthesis. It shows a very superior catalytic activity in alkylation reaction of cresol and isobutylene, dodecene and naphthalene, dodecene and phenol; and the catalytic activity of packaged phosphotungstic acid is not significantly decreased after it is reused for six times. The life of PW-USY catalyst is also evaluated during alkylation of naphthalene with dodecene in a small fixed bed. After a continuous alkylation of 720 h, the catalyst activity is not significantly decreased. Compared with HUSY, it has better reusability, longer catalyst life, and at the same time it can solve the loss of activity, showing good prospects for industrial applications.4. To get some insight on the mechanism of catalyst deactivation, the catalysts before and after reaction are both characterizated by BET, FT-IR, XRD, TG-DSC, NH3-TPD analysis, as well as the residues. It is found that starting material cresol will form carbonized product, polymer alkylate product at high temperature, which can cover the active center and other channels, resulting zeolite deactivation. |
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