Method for mass producing butyl acetate by reactive distillation method and using sulfuric acid as catalyst

Abstract

The refers to a mass production method of isobutyl acetate which uses hydric sulphate as accelerant by reaction fractional distillation, using ethyl acetate and butyl alcohol as raw material, concentrated sulfuric acid as accelerant, continue producing isobutyl acetate by reaction fractional distillation, the whole production system contains three towers, reaction fractionating tower, azeotropy tower and eater fractionating tower, the reaction fractionating tower, azeotropy tower are setted side by side. The ethyl acetate, butyl alcohol and concentrated sulfuric acid are drived into feeder column plate of reaction fractionating tower after esterification prereaction, the gas phase of prereactor going into feeding phase of reaction fractionating tower, the gas phase on top of reaction fractionating tower going into column plate of cellar of azeotropy towder, the liquid phase of towder bottom going into mesomere of eater fractionating tower, the butyl product is continue discharged from side tower. This invention combines the technique which using sulfuric as accelerant by mean improvement of reaction fractional distillation technique, not only ustilizing the advanced technology of reaction fractional distillation, but also making the liquid accelerant's characters of convenience to operate, easy to enlarge production scale getted adequate use.

Description

Technical field: [0001] The present invention relates to a kind of method of producing butyl acetate, especially relate to a kind of continuous, large-scale production method of butyl acetate that combines sulfuric acid as catalyst and reactive distillation method. Background technique: [0002] Butyl acetate is an environmentally friendly ester solvent that is easily degraded in nature and can replace aromatic solvents such as toluene and xylene. It is widely used in coatings, paints, inks, adhesives and medicines. [0003] The early production method of butyl acetate generally uses sulfuric acid as a catalyst, and performs intermittent esterification first. After the reaction is completed, it is neutralized with soda ash, and then refined by distillation. Adopt such intermittent reaction technique, the one, production efficiency can't be improved, and production capacity is difficult to improve, and energy consumption is big, and production cost is high; 》Requirements for...

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Problems solved by technology

Adopt such intermittent reaction technique, the one, production efficiency can't be improved, and production capacity is difficult to improve, and energy consumption is big, and production cost is high; 》Requirements for superior products

[0004] In the 1990s, with the development and application of reactive distillation technology, some units in China began to study the use of this technology to produce butyl acetate, but generally solid acids such as heteropoly acids were used as catalysts, which have not been used. The technology combining liquid as catalyst and reactive distillation has been applied to industrial production

[0005] The use of solid acid as a catalyst has many disadvantages: first, this catalyst is very expensive, and its catalytic activity will decrease after a period of use, it is very troublesome to replace, and the cost of use is very high; , and it is easy to cause impurities to accumulate in the esterification tank or reactive distillation tower, which affects the evaporation of the material and ultimately affects the quality of the product; the third is that the solid catalyst is not like a liquid catalyst, it is difficult to achieve homogeneous catalysis, and the solid It is difficult to achieve a uniform heat transfer effect, and it is easy to cause local overheating, coking of reactants, etc., which affects product quality and production efficiency; fourth, if solid acid is used as a catalyst, it is difficult to increase production capacity, and the annual cost of a single set of equipment The output is basically less than 10,000 tons, and it is difficult to form a large-scale production capacity

[0007] Chinese patent ZL 94108405.1 discloses a method and equipment for producing n-butyl acetate by continuous catalytic rectification, but its reactive distillation equipment adopts a tower-type device, and the content of n-butyl acetate generated by it is only (95-97 )%, which is only equivalent to the requirements of qualified products in the GB / T 3729-91 standard, far below the requirements of contemporary butyl acetate users

[0008] Chinese patent ZL 97121674.6 discloses a continuous process for the production of butyl acetate, using heteropolyacids as catalysts, and does not use reactive distillation

[0009] The method for continuously producing butyl acetate disclosed in Chinese patent ZL 00107970.0, although sulfuric acid is also used as a catalyst, does not adopt the reactive distillation method

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