Method for high selectively synthesizing dimethylbenzene through benzene and methanol alkylation reaction

Abstract

The invention relates to a method for high selectively synthesizing dimethylbenzene through benzene and methanol alkylation reaction. The method takes the benzene as a raw material a, a toluene is taken as a raw material b, the methanol is taken as a raw material c, according to the molar ratio, a / c equals to 0.50-3.00 / 1.00, b / c equals to 0.60-3.00 / 1.00, under the conditions that the reaction temperature is between 380 and 480 DEG C, the reaction pressure is between 0.50 and 6.0 mega pascals, the reaction space velocity is between 0.5 and 5.0 h<-1> and the carrier gas is H2, N2 or CO2, the dimethylbenzene is produced in a fixed bed reactor under the catalysis of molecular sieve based catalysts, the catalysts are one or a plurality of molecular sieves of zeolite socony mobile-5 (ZSM-5), USY, mobile composite of matter (MCM)-22 or EU-1, a load metallic oxide is Mo, Ni or La metallic oxide, and the load of the metallic oxide is 0.50-10.00%. The method utilizes the benzene with relative surplus capacity and the inexpensive methanol to produce the dimethylbenzene with high industrial added value. The appropriate molecular sieve based catalyst is adopted, the utilization ratio of the methanol alkylation reaction for high selectively synthesizing the dimethylbenzene cannot be less than 90%, and the catalyst stability can satisfy industrial application requirements. Moreover, the toluene is added into the reaction raw materials, so that toluene byproducts can be inhibited from being produced; and in addition, an H2, N2 or CO2 carrier gas atmosphere is adopted, so that the reaction stability of the catalyst is enhanced.

Description

Technical field [0001] The present invention involves a method of high selective synthesis of dyshayne -based reactions in a benzene and methanol. Background technique [0002] For two metamornenes (PX) is the largest carbon octopus hydrocarbons in the industry, which is the forefront of benzene acid (PTA).Pharine is an important raw material for the polyester industry and plastic industry. Among the global PX consumption structure, more than 80%of PX is used to produce PTA.It is also widely used in the fields of medicine, pesticides, dyes, and solvents.The market for vrsenopine needs to be rising, and insufficient production capacity has always existed. [0003] The traditional process of production of dyshane in industries is mixed with dysfamene -. The second is toluene and C. 9 Grandmark dismissal and alkyl transfer.Patent CN200610117849.2 Reported a toluene -selective vibration reaction catalyst for toluene -selective visitories to dyshayne, achieving high catalytic activity...

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Problems solved by technology

However, the patent only describes the initial activity of the catalyst, and its stability and methanol alkylation rate data are missing; in addition, the first product of the alkylation of benzene and methanol is toluene, and 89% of the product selectivity in the patent CN200910242740.5 is toluene and xylene selectivity, the target product xylene selectivity may be lower

The method reported in patent CN201210233696.3 involves the reflux of materials, but does not mention conversion rate, selectivity and stability data

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