Hydrolyzation separation apparatus for methyl acetate and technique

Abstract

The invention provides a hydrolyzing and separation device of methyl acetate and a technique method thereof, which more particularly relates to a novel technique to catalyze and hydrolyze methyl acetate by a reaction bulkhead distillation tower, which can organically combine reaction process, product separation and recovery of no reactant into the tower. A separator extending from the upper part of the tower to the lower part of the tower is arranged on the vertical direction in the conventional distillation tower, the upper part of one side of which is covered and the other side of which is filled with a catalyst; therefore, the inner space of the reaction bulkhead distillation tower is divided into five regions with different functions. The hydrolyzing and separation device of methyl acetate can fully unleash the advantage of bulkhead tower and reaction distillation, and can cause hydrolysis reaction, product separation and recovery of non reactant to be realized in the same tower. The device provided by the invention and the technique process thereof can obtain the methyl acetate with 60 percent to 99.99 percent hydrolysis rate and products with high purity, restrain side effect effectively, reduce the volume of equipment markedly, simplify process, and reduce energy consumption and operation cost.

Description

technical field [0001] The invention relates to a chemical reaction separation device and process, in particular to an equipment and process for catalytic hydrolysis of methyl acetate by using a reactive distillation partition tower, which can combine the hydrolysis reaction of methyl acetate and the separation of its products in one tower completed. Background technique [0002] Methyl acetate is a by-product in the production process of polyvinyl alcohol. At present, all PVA manufacturers hydrolyze methyl acetate into acetic acid and methanol for recycling. The current methyl acetate hydrolysis process at home and abroad mainly adopts fixed bed cation exchange resin catalytic hydrolysis process and reactive distillation hydrolysis process. [0003] The shortcoming of fixed-bed cationic exchange resin catalytic hydrolysis process is: the hydrolysis rate of methyl acetate is low, when the molar ratio of water and methyl acetate is 1: 1, only reaches 23%~25%; With multiple ...

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Problems solved by technology

[0003] The shortcoming of fixed-bed cationic exchange resin catalytic hydrolysis process is: the hydrolysis rate of methyl acetate is low, when the molar ratio of water and methyl acetate is 1: 1, only reaches 23%~25%; Multiple azeotropic systems, the separation process is complicated; a large amount of unhydrolyzed methyl acetate needs to be recycled, coupled with the complicated separation process, resulting in large equipment investment and high energy consumption for separation

However, there are still some defects in this technology: as the above-mentioned patents generally operate with full reflux at the top of the tower, in order to achieve sufficient hydrolysis rate, it must be operated under the conditions of high water-ester ratio and high reflux flow, and the energy consumption is large; Both methanol and water are drawn from the bottom of the tower, and cannot be effectively separated. After the reactive distillation tower, a series of rectification towers must be used to further separate the reaction products, and intermediate components in the general rectification process will appear. The remixing phenomenon of methanol has a low thermodynamic efficiency; in addition, the acetic acid and methanol in the bottom of the reactive distillation tower and the extraction pump at the bottom of the tower and its pipeline are prone to reverse reactions to form methyl acetate, thereby reducing the hydrolysis rate

These factors all lead to the decrease of its hydrolysis rate, the consequences of high energy consumption and equipment investment, which are not conducive to improving economic benefits

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