Rectification device and method for extracting high-purity mesitylene product from oil generated by trimethylbenzene isomerization reaction

Abstract

The invention discloses a rectification device and method for extracting a high-purity mesitylene product from trimethylbenzene isomerization reaction generated oil, and belongs to the technical fieldof rectification. According to the rectification device, a dividing wall rectifying tower structure is adopted by a light component removal rectifying tower 1, and is used for simultaneously removinglight and heavy impurity components from trimethylbenzene isomerization reaction generated oil and extracting trimethylbenzene mixed component oil with impurities basically removed; one of a productrectifying tower 2 and a concentration rectifying tower 3 is operated under positive pressure, the other one is operated under reduced pressure, and tower top high-temperature oil gas of the positivepressure operation and tower top high-temperature oil gas after the positive pressure operation of the light component removal rectifying tower 1 are jointly used as tower bottom rectifying heat sources of the tower under reduced pressure operation in the two towers for combined thermal coupling utilization. Based on dividing wall tower rectification, stepped rectification and heat integration coupling principles, an energy-saving and economical rectification process for purifying a high-purity mesitylene product from trimethylbenzene isomerization reaction generated oil and recovering trimethylbenzene isomerization reaction raw oil is realized, and a high-purity mesitylene product can be co-produced in combination with product requirements.

Description

technical field [0001] The invention relates to an energy-saving combined production device and a process method which adopt partition wall rectification, cascade rectification, and thermal energy integrated recycling technologies in the rectification process of mesitylene products, and belong to the rectification technical field. Background technique [0002] Mesitylene is an important organic chemical raw material, which can be used to prepare synthetic resin, M acid, mesitidine antioxidant 330, high-efficiency wheat field herbicide, polyester resin stabilizer, alkyd resin plasticizer, and Used in the production of reactive brilliant blue, acid dyes, K-3R and other dye intermediates, as a developer for silicone photosensitive sheets in the electronics industry, etc. [0003] At present, the mesitylene product obtained by purifying more than 98.0% of the mesitylene product through the reaction of the mesitylene isomerization method has become the mainstream production proce...

AI Technical Summary

Problems solved by technology

The traditional three-tower sequential rectification process of removing light, purifying mesitylene, and recovering the raw material oil of the mesitylene reaction is generally used for rectifying and purifying more than 98.0% of mesitylene products from the oil generated by the isomerization reaction of mesitylene. The traditional three-tower refining The distillation process cannot directly realize the purification of mesitylene products, and because the difference between the light and heavy key components in the generated oil that affect the purity of the separated product and the boiling point and relative volatility of mesitylene is small, the rectification column needs to use high-level theoretical trays, High reflux ratio operation, rectification energy consumption has become the main component of mesitylene product cost

The content of light and heavy components in the oil produced by the isomerization reaction of trimethylbenzene is 3.5-7.0%, the content of mesitylene is 20.0-25.0%, and the content of the reaction raw material of trimethylbenzene to be recovered is 60.0-70.0%. As can be seen from the distribution of the above components: the task of light removal and weight removal is too low, and the task of recovering mesitylene products and reaction raw materials is too high, which makes sequential rectification difficult to carry out the design of each rectification column rationally and economically. The content of mesitylene in the oil produced by isomerization reaction is low, and when the mesitylene product needs to achieve higher purity and product yield, the purification tower of the mesitylene product needs a larger tower diameter, a higher tower height and production reflux Ratio, resulting in high device construction costs and high production energy consumption costs

[0004] At present, trimethylbenzene products basically come from the rectification and separation of reformed heavy aromatics. The components of o-methylethylbenzene and butylbenzene in the raw material that have a similar boiling point to trimethylbenzene seriously affect the purity of the trimethylene product separated by rectification. The production purity is higher than The technical and economic efficiency of 99.0% trimethylbenzene products is poor; it is difficult to effectively supply high-purity metamethylbenzene products with a purity higher than 99.5%

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