Thermodynamic analysis of benzene alkylation with propylene
Relevance of the research is caused by broad application of alkylation in industry and the necessity to develop a mathematical model adequate on the predicting ability and suitable for solving the technological problems in producing cumene with aluminum chloride. The main aim of the study is to defi...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | Russian |
| Published: |
Tomsk Polytechnic University
2019-05-01
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| Series: | Известия Томского политехнического университета: Инжиниринг георесурсов |
| Subjects: | |
| Online Access: | http://izvestiya.tpu.ru/archive/article/view/1612 |
| Summary: | Relevance of the research is caused by broad application of alkylation in industry and the necessity to develop a mathematical model adequate on the predicting ability and suitable for solving the technological problems in producing cumene with aluminum chloride. The main aim of the study is to define and to study the thermodynamic and kinetic regularities of benzene alkylation with propylene in the presence of aluminum chloride applying the methods of quantum chemistry. The methods used in the study: electronic-structural method based on density functional theory (DFT, DFT) at B3LYP. Search for transition state of the reaction in the presence of Lewis acids was performed by QST2 at B3LYP / 6-31 ++ G(d,p) and LSDA / 6-31 ++ G(d,p). The results. The thermodynamic parameters of the main reactions, defined by the methods of quantum chemistry, proceeding in the course of obtaining cumene, allowed comparing two competing reactions - alkylation and transalkylation. As a result it was ascertained that the first reaction possesses the lowest activation energy (for benzene alkylation with propylene it is 150,94 kJ/mol at preexponential multiplier value in Arrhenius's 1,58×105 equation, for transalkylation reaction the activation energy and a preexponential multiplier in Arrhenius's equation equal 156,13 kJ/mol and 5,34×104 , respectively). The regularities determined became the basis of the mathematical model of the alkylation process that allows predicting the quality of the alkylate depending on the process mode in the alkylation reactor. Accuracy of calculations by the model of such indicators as the yield of main and secondary components that determine the quality of the product (n-propylbenzene, ethylbenzene, polyalkilbenzenes) does not exceed 7-10 %. |
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| ISSN: | 2500-1019 2413-1830 |