Production process and device of high-purity methylal

Abstract

The invention discloses a production process of high-purity methylal, which belongs to the technical field of methylal production, and comprises the following steps: mixing methanol and a formaldehydesolution, feeding the mixed solution in a reactive distillation tower for a reaction to obtain an azeotropic mixture of methylal and methanol, wherein a catalyst in the reactive distillation tower isstrongly acidic cation exchange resin, and the resin is modularly mounted in the reactive distillation tower, separating the azeotropic mixture by a pressurized distillation tower, condensing a separated product at the bottom of the pressurized distillation tower to obtain a product, wherein a mixture of methylal and methanol is obtained at the top of the pressurized distillation tower, and feeding one part of the mixture into a catalyst layer at the lower part of the reactive distillation tower for a reaction. According to the process, the double towers of the reactive distillation tower andthe pressurized distillation tower are adopted, the quality of the obtained product is high, the purity of the product methylal is greater than 99.9%, the moisture content is less than 0.03%, the quality of the product is obviously improved, wastewater is easy to treat, the production energy consumption is reduced, and the equipment investment is small.

Description

technical field [0001] The invention relates to the technical field of methylal production, in particular to a synthesis process and device for high-purity methylal. Background technique [0002] Methylal is obtained by condensation reaction of methanol and formaldehyde solution as raw materials, and then purified by rectification. It is widely used in cosmetics, pharmaceuticals, industrial automotive supplies, insecticides, leather polishes, cleaning agents, and rubber industries. , paints, inks and other products. [0003] For the production process of methylal, there have been many reports in the prior art. Because the methylal obtained after the reaction of methanol and formaldehyde contains impurities such as methanol and formaldehyde, the existing methods generally adopt the addition of various alcohols and their derivatives for extraction, rectification and purification. Although these methods can greatly improve the formaldehyde The purity of acetal, for example, c...

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Problems solved by technology

[0005] 1. It is still necessary to set up a pre-reactor, and the equipment investment and equipment occupy a large area; 2. The purity of the methylal obtained, although in this patent document, The purity data is not disclosed, however, the inventor of the present application used the method to prepare methylal during the test process, and the obtained methylal had a purity of 98.21% and a methanol content of 1.73%, and there is still room for further improvement in its purity In addition, the methylal of gained, its moisture content is 0.06%, and its moisture content is higher, influences the quality of methylal product, in addition, formaldehyde content 3.3% in the waste water at the bottom of the reaction distillation tower, methanol content 0.19%, Increased the difficulty of wastewater treatment

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