Continuous production method for 2,2,4-trimethyl-1,3-pentanediol isobutyrate

Abstract

The invention discloses a continuous production method for 2,2,4-trimethyl-1,3-pentanediol isobutyrate. A two-step method fixed bed continuous reaction process and a solid catalyst are adopted, wherein the catalyst is a solid catalyst Cs-K / SiO2 which is prepared by taking spherical silicon oxide as a carrier to carry caesium-potassium double-alkali metal active components. The method comprises the following steps: adopting two serial tubular type fixed bed reactors, firstly feeding a preheated isobutyraldehyde raw material into a first tubular type fixed bed reactor for an aldol condensation reaction, subsequently feeding an obtained an aldol condensation product into a second tubular type fixed bed reactor for intramolecular Cannizzaro reaction, and continuously reacting so as to obtain a target product. Due to adoption of a two-step method fixed bed continuous reaction process, the method is not only high in isobutyraldehyde conversion rate and product selectivity, but also high in production efficiency, simple in reaction operation, beneficial for energy conservation and discharge reduction and has a large-scale continuous industrial production prospect.

Description

technical field [0001] The invention belongs to the field of fine chemical industry and relates to a continuous preparation method of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate. Background technique [0002] 2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate (abbreviated as alcohol ester-12) is a high-boiling, polyfunctional glycol ester, which is colorless at room temperature Transparent liquid with a boiling point of 255°C, insoluble in water, can be directly or indirectly used as coating additives, lubricants, solvents, plastic additives, etc., and has a wide range of uses. With the increasingly stringent environmental protection regulations and the continuous improvement of water-based architectural coating industry standards, alcohol ester-12 has become a world-renowned water-based architectural coating (usually latex) because of its excellent film-forming effect, non-toxic and harmless, etc. paint), widely used in vinyl acetate homopolymerization and copolymerizatio...

AI Technical Summary

Problems solved by technology

[0004] Chinese patent CN1098712A discloses a synthetic method using NaOH as a two-step batch process of the catalyzer. The so-called two-step method is that the first step is under the action of dilute lye, and isobutyraldehyde is subjected to low-temperature aldol condensation reaction. The first step is to carry out intramolecular Cannizzaro reaction under the action of concentrated lye, the conversion rate of isobutyraldehyde can reach 69%, and the product selectivity can reach 89%, but there are many disadvantages in this method: low conversion rate, a large amount of By-products, products are difficult to separate, and the process is complex, requiring washing process, large waste water discharge

[0005] Chinese patent CN1429809A discloses a synthesis method using concentrated NaOH solution as a catalyst in a two-stage tubular reaction process. The first-stage tubular reaction temperature is low at 30-40°C; the second-stage tubular reaction temperature is relatively high at about 90°C. ℃, this method can realize liquid-liquid heterogeneous continuous reaction, but the single-pass conversion rate is very low, only 60%, the selectivity is not high, about 88%, and the post-treatment process is complicated, requiring phase separation and washing processes, and waste water discharge Big

However, this method also has many disadvantages: the use of dilute NaOH solution as the catalyzer of the first step reaction process will produce a large amount of waste water and pollute the environment; 2 ·8H 2 O is used as the catalyst of the second step reaction process, because Ba(OH) 2 ·8H 2 O is a highly toxic substance, and a large amount of catalyst is used in the reaction, which will produce a large amount of toxic waste residue, which does not conform to the concept of green environmental protection

[0012] To sum up, in the prior art, whether it is a one-step batch process or a two-step batch process, there are various problems such as low production efficiency, high production cost, high energy consumption, and high discharge of three wastes. It is difficult to realize large-scale continuous clean chemical industrial production

The above-mentioned two-stage tubular reaction process using NaOH solution as a catalyst also has complex post-treatment processes, requires phase separation, water washing and other processes, and has no industrialization prospects.

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