Process for preparing and extracting tert-butyl acetate

Abstract

The invention discloses a method for preparing and purifying tert-butyl acetate. Acetic acid and C4 containing isobutene are continuously added to an esterification tower equipped with a strong acid ion exchange resin catalyst, and the molar ratio of acetic acid and isobutene is 1:0.30 to 1:0. 5.00, the feed space velocity of acetic acid is 0.5~5.0h-1, the amount of catalyst is 30~90ml, the pressure is 0.5~2.0MPa, and the reaction temperature is 30~110℃, the esterification reaction is carried out to obtain the crude ester; the crude ester is sent to The separation tower is obtained by controlling the reflux temperature of the top gas phase at 85-100°C for deacidification, 70-85°C for dehydrocarbonation, 78-90°C for alcohol removal, and finally rectification at 90-100°C tert-butyl acetate product. The invention uses abundant C4 in refinery as raw material, which can greatly reduce the production cost of the product, and also overcomes the problem of water separation in the traditional acid / alcohol process, which leads to increased energy consumption; realizes continuous esterification and separation Purification, the product content of tert-butyl acetate can reach more than 99.5%.

Description

1. Technical field: [0001] The present invention relates to a kind of method for preparing tert-butyl acetate, particularly relate to a kind of method with acetic acid and C 4 A method for preparing and purifying tert-butyl acetate as a raw material. 2. Background technology: [0002] Tert-butyl acetate is a colorless liquid that can be mixed with alcohol and ether, soluble in acetic acid, almost insoluble in water, is an excellent gasoline anti-shock agent, and can be used as a solvent for nitrocellulose, etc. [0003] At present, the methods for industrially producing tert-butyl acetate include: 1. acetic anhydride method: taking tert-butyl alcohol and acetic anhydride as raw materials to synthesize tert-butyl acetate, wherein the catalysts used include zinc chloride, lithium chloride, lithium perchlorate, nitric acid Cerium ammonium, pyridine, triethylamine, 4-dimethylaminopyridine (DMAP), tin tetrachloride, etc., but zinc chloride is easy to absorb moisture, organic ami...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that (isobutylene) dimer accumulation and catalyst failure often occur in the tower during the reaction, resulting in the formation of muddy deposits and the need to shut down and clean out the tower, and the dimer of olefins increases The separation and purification of tert-butyl acetate is difficult

So far, the use of acetic acid and C containing a certain amount of isobutylene 4 The reaction obtains crude ester, and the method of obtaining tert-butyl acetate with a purity of more than 99.5% through deacidification, dehydrocarbonation and dealcoholization has not been reported

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