Method for separating neopentyl glycol from DL-pantoic acid lactone synthesis feed liquid

A technology of pantolactone and neopentyl glycol, which is applied in the field of separation of neopentyl glycol, can solve problems such as removal by chemical methods, and achieve high-purity results

Active Publication Date: 2022-05-13
安徽泰格生物科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the chemical properties of neopentyl glycol are relatively stable, and it is difficult to remove them by chemical m

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0035] This embodiment provides a method for separating neopentyl glycol from DL-pantolactone synthesis feed liquid, comprising the following steps:

[0036] (1) add formaldehyde aqueous solution 860g (formaldehyde content 35wt%), anhydrous sodium carbonate 30g in the reactor, drip isobutyraldehyde 720g (isobutyraldehyde content 99wt%) under the condition of heat preservation 40 ℃, dropwise after finishing , heat preservation reaction 4h, generate hydroxy pivalaldehyde;

[0037] (2) The reaction solution obtained in step (1) is cooled to 5° C., and 10 mol (224 L) of hydrocyanic acid gas is passed into it, and the reaction generates hydroxypivalonitrile;

[0038] (3) Adjust the pH of the reaction solution obtained in step (2) to 1 with concentrated sulfuric acid, heat up to 90° C. for reflux reaction for 2 hours, and generate DL-pantolactone;

[0039] (4) The reaction solution obtained in step (3) is cooled to normal temperature, and the pH is adjusted to neutrality with 30% s...

Embodiment 2

[0042] This embodiment provides a method for separating neopentyl glycol from DL-pantolactone synthesis feed liquid, comprising the following steps:

[0043] (1) Add 860g of formaldehyde aqueous solution (35wt% of formaldehyde content) in the reactor, anhydrous sodium carbonate 30g, dropwise isobutyraldehyde 720g (99wt% of isobutyraldehyde content) under the condition of heat preservation 45 ℃, dropwise after finishing , heat preservation reaction 5h, generate hydroxy pivalaldehyde;

[0044] (2) The reaction solution obtained in step (1) is cooled to 10° C., and 10 mol (224 L) of hydrocyanic acid gas is passed into it, and the reaction generates hydroxypivalonitrile;

[0045] (3) Adjust the pH of the reaction solution obtained in step (2) to 2 with concentrated sulfuric acid, heat up to 85° C. for reflux reaction for 4 hours, and generate DL-pantolactone;

[0046] (4) The reaction solution obtained in step (3) is cooled to normal temperature, and the pH is adjusted to neutral...

Embodiment 3

[0049] This embodiment provides a method for separating neopentyl glycol from DL-pantolactone synthesis feed liquid, comprising the following steps:

[0050] (1) Add 860g of formaldehyde aqueous solution (35wt% of formaldehyde content) in the reactor, anhydrous sodium carbonate 30g, drip isobutyraldehyde 720g (99wt% of isobutyraldehyde content) under the condition of heat preservation 43 ℃, dropwise after finishing , heat preservation reaction 4.5h, generate hydroxy pivalaldehyde;

[0051] (2) The reaction solution obtained in step (1) is cooled to 8° C., and 10 mol (224 L) of hydrocyanic acid gas is passed into it, and the reaction generates hydroxypivalonitrile;

[0052] (3) Adjust the pH of the reaction solution obtained in step (2) to 1.5 with concentrated sulfuric acid, heat up to 88° C. for reflux reaction for 3 hours, and generate DL-pantolactone;

[0053] (4) The reaction solution obtained in step (3) is cooled to normal temperature, and the pH is adjusted to neutrali...

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PUM

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Abstract

The invention provides a method for separating neopentyl glycol from a DL-pantoic acid lactone synthesis feed liquid. The method comprises the steps that the DL-pantoic acid lactone synthetic feed liquid is dewatered and then added into a rectifying tower to be rectified, the rectifying tower sequentially comprises a tower bottom, a tower lower part, a tower middle part and a tower top from bottom to top, the temperature of the tower bottom is controlled to range from 170 DEG C to 175 DEG C, the temperature of the tower lower part is controlled to range from 160 DEG C to 165 DEG C, the temperature of the tower middle part is controlled to range from 145 DEG C to 150 DEG C, and the temperature of the tower top is controlled to range from 115 DEG C to 120 DEG C; the vacuum pressure in the rectifying tower is-0.093 to-0.099 MPa, and collecting neopentyl glycol from the top of the tower. The method provided by the invention has a relatively high removal rate on the neopentyl glycol in the DL-pantoic acid lactone synthesis feed liquid, and the separated neopentyl glycol has relatively high purity.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a method for separating neopentyl glycol from DL-pantolactone synthesis feed liquid. Background technique [0002] As an important chemical intermediate, DL-pantolactone is an important raw material for the synthesis of calcium pantothenate and panthenol, and it plays an important role in feed, cosmetics and medicine. [0003] According to relevant literature reports, adopting the existing technology to produce DL-pantolactone, one of the important by-products, neopentyl glycol, cannot be avoided, and the output of neopentyl glycol as a by-product is relatively large, accounting for 3% of the total system. -5%. [0004] Neopentyl glycol (NPG) is a white crystalline solid, odorless, hygroscopic, mainly used in the production of unsaturated resins, oil-free alkyd resins, polyurethane foams and elastomer plasticizers, surfactants, Insulating materials, prin...

Claims

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Application Information

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IPC IPC(8): C07C29/80C07C31/20C07D307/33C07C45/75C07C47/19C07C253/16C07C255/12
CPCC07C29/80C07D307/33C07C45/75C07C253/16C07C47/19C07C255/12C07C31/20Y02P20/10
Inventor 李涛蔡奇峰赵毅徐帝汪洪湖刘伟
Owner 安徽泰格生物科技有限公司
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