Prepn of phosphotungstic anion intercalated strontium aluminate hydrotalcite-solid acid alkylation catalyst

Abstract

The present invention is the preparation process of phosphotungstic anion intercalated strontium aluminate hydrotalcite as one kind of solid acid catalyst for C9 arene alkylation to separate and prepare trimethylbenzene. The preparation process includes the following steps: dissolving Al(NO3)3.9H2O in 15-21 weight portions and Sr(NO3)2 in 18-25 weight portions separately in deionized water of 100 weight portions and mixing via stirring; dropping 0.1 mol / L concentration NaOH or CsOH solution slowly while heating to reach pH 8.2-9.1; dispersing the precursor in deionized water to form suspension with solid content 7-10 %, dissolving phosphotungstic acid in 3-5 wt% in the suspension, and ion exchanging and filtering in a ultrasonic vibrator; adding NaOH or CsOH solution to regulate pH value to 6.0-6.5, suction filtering and stoving at 60-100 deg.c in an oven.

Description

technical field [0001] The invention relates to a preparation method of a phosphotungstic acid anion intercalation aluminum strontium hydrotalcite alkylation solid acid catalyst used in the process of preparing mesitylene by alkylation and separation of mixed C9 aromatic hydrocarbons. Background technique [0002] Mesitylene (1,3,5-trimethylbenzene) is an important chemical raw material, and it can be used as a raw material to prepare dye intermediates, mesitylene, wheat field herbicides, and ultraviolet absorbers 2,4,6-trimethylbenzene Methyl phenol, antioxidant 330, etc. It is also the main raw material for the preparation of mesitylenesulfonic acid, trimesic acid, trimesic triacetic acid, etc. Its industrial production methods mainly include isomerization and alkylation separation and purification methods. The isomerization method uses mesitylene as a raw material to carry out an isomerization reaction to generate mesitylene, but due to technical reasons, it is difficult...

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Problems solved by technology

But the main problem that this method exists at present is: the alkylation catalyst adopts anhydrous AlCl 3 , while anhydrous AlCl 3 The activity is too high, and part of mesitylene also participates in the alkylation reaction, which reduces the yield of mesitylene; while AlCl 3 It has strong water absorption and corrosiveness, and has high requirements for production equipment; anhydrous AlCl 3 It is only active after forming a complex with C9. After the reaction, the complex needs to be washed with water to remove AlCl 3 , leading to complex post-processing, generating a large amount of waste water and waste residue, which is easy to cause environmental pollution and affect human health. AlCl in the product 3 There are still residues, which limits the application range of the product