Preparation method of dibutoxy methane

Abstract

The invention relates to a preparation method of dibutoxy methane. The preparation method is characterized by comprising the following step of: undergoing a normal-pressure gap type aldol condensation reaction on formaldehyde and n-butyl alcohol under the action of a solid acid catalyst by taking n-butyl alcohol as an azeotropic dehydrating agent in a reactor with a stirrer, a condenser and a water knockout vessel to obtain the dibutoxy methane, wherein the molar ratio of the formaldehyde to the n-butyl alcohol is 1:2-1:4, the concentration of a formaldehyde solution is more than or equal to 25 percent by mass, the reaction temperature is 60-140 DEG C, the reaction time is 0.5-8 hours, the solid catalyst is an HZSM-5 molecular sieve or an active carbon immobilized sulfuric acid catalyst, the active ingredient of the active carbon immobilized sulfuric acid catalyst is sulfuric acid, the immobilized quantity of acid is 15-25 percent by mass, and the using amount of the solid acid catalyst is 0.1-8 percent of the total mass of reactants. The method has the advantages of easiness in separation of the solid acid catalyst from a product, small corrosion to equipment and catalyst recyclability, and is a novel, efficient and environmentally-friendly production method.

Description

technical field [0001] The present invention relates to a preparation method of industrial grade dibutoxymethane. Dibutoxymethane is also known as formaldehyde dibutylacetal, and its structural formula is: CH 3 (CH 2 ) 3 OCH 2 O(CH 2 ) 3 CH 3 . It belongs to the field of organic chemical technology. Background technique [0002] Dibutoxymethane is a colorless transparent liquid with a mild, fruity odor. Boiling point 180 ℃, density 0.84 g / cm 3 , flash point 60 ℃. Slightly soluble in water, stable in nature, need to avoid contact with oxidants, thermal decomposition temperature is 300 ℃. [0003] Dibutoxymethane can be used as a good solvent for casting core aggregates and binders, and can also effectively reduce the emission of particles during the combustion of diesel fuel, and can increase the cetane number of diesel. Dibutoxymethane is also used as a raw material for the preparation of polyoxymethylene dialkyl ether, a diesel additive. [0004] Dibutoxymethan...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the dehydration entrainer is added, which must be removed from the product in the end, which increases the complexity and cost of the operation

US2010076226 (A1) adopts butanol and a 30-50% formaldehyde solution composed of paraformaldehyde, methanol and water as raw materials, and concentrated sulfuric acid as a catalyst. Neutralize sulfuric acid with a neutralizer, then purify

Moreover, concentrated sulfuric acid is a strongly acidic and oxidizing substance, which requires high equipment and has a certain impact on the stability of the product, and cannot be reused.