Preparation method of triethyl citrate

A technology of triethyl citrate and citric acid, which is applied in the field of preparation of triethyl citrate, can solve the problems of difficult reaction end point, many reaction side reactions, and dimness, so as to reduce side reactions, prevent insufficient reaction, reduce Harmful effect

Active Publication Date: 2011-06-01
蚌埠丰原涂山制药有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is difficult to control the reaction end point only by controlling the reaction time, and the reaction time varies in different seasons, which may easily cause many side reactions and insufficient reaction, resulting in low yield of the product; in addition, bec...

Method used

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  • Preparation method of triethyl citrate

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Embodiment 1

[0026] 1. Preparation of crude triethyl citrate: In a 2500ml three-necked bottle, install a thermometer, condenser, and mechanical stirring. Add 1200g of absolute ethanol (or recovered ethanol: more than 95%), start stirring and preheat to 50°C, add 800g of citric acid, 6ml of concentrated sulfuric acid and slowly heat to reflux, and collect the distillate as the next batch of feed. Control the distillation speed to about 20ml / hour (the addition of absolute ethanol in time is the same as the amount of distillate) to react for 20 hours, and start to detect the end point.

[0027] Use a pipette to pipette 1ml of the reaction feed solution into a small beaker and add 3-5 drops of phenolphthalein indicator. Titrate with 1% sodium hydroxide titration until the feed liquid turns red, record the amount of sodium hydroxide titration, when the amount of 1% sodium hydroxide titration is less than 5ml, it can be regarded as complete reaction, when the acid value is less than 5, it can be...

Embodiment 2

[0030] 1. Preparation of crude triethyl citrate: In a 2500ml three-necked bottle, install a thermometer, condenser, and mechanical stirring. Add 1000g of absolute ethanol (or recovered ethanol: more than 95%), start stirring and preheat to 60°C, add 800g of citric acid, 6g of sodium benzenesulfonate and slowly heat to reflux to collect the distillate as the next batch of feed. Control the distillation rate to about 28ml / hour (the addition of absolute ethanol in time is the same as the amount of distillate) to react for 22 hours, and start to detect the end point.

[0031] Use a pipette to pipette 1ml of the reaction feed solution into a small beaker and add 3-5 drops of phenolphthalein indicator. Titrate with 1% sodium hydroxide titration solution until the feed liquid turns red, record the sodium hydroxide titration solution consumption, treat that the reaction is complete when the 1% sodium hydroxide titration solution consumption is less than 5ml, and distill off excessive ...

Embodiment 3

[0034] 1. Preparation of crude triethyl citrate: In a 200°C reaction kettle, install a thermometer, condenser, and mechanical stirring. Add 120kg of absolute ethanol (or recovered ethanol: more than 95%), start stirring and preheat to 50°C, add 80kg of citric acid, 600ml of concentrated sulfuric acid and slowly heat to reflux, and collect the distillate as the next batch of feed. Control the distillation speed to about 20 liters / hour (the addition of absolute ethanol in time is the same as the amount of distillate) and react for 20 hours, and start to detect the end point.

[0035] Use a pipette to pipette 1ml of the reaction feed solution into a small beaker and add 3-5 drops of phenolphthalein indicator. Titrate with 1% sodium hydroxide titration until the feed liquid turns red, record the amount of sodium hydroxide titration, when the amount of 1% sodium hydroxide titration is less than 5ml, it can be regarded as complete reaction, when the acid value is less than 5, it can...

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Abstract

The invention relates to a preparation method of triethyl citrate. The preparation method is as follows: by deeply studying the preparation process of triethyl citrate, setting a reaction feed ratio; then adding catalyst to perform reflux reaction; then utilizing phenolphthalein as an indicator and sodium hydroxide to perform titration to determine the reaction end point; utilizing weak base to neutralize less acidic materials in the obtained product, and eluting sodium carbonate with purified water; and finally utilizing activated carbon to decolor, thus obtaining the pure triethyl citrate product. Compared with the prior art, the preparation method provided by the invention has the advantages that the reaction end point is strictly controlled, unnecessary side reactions are reduced, thereduction of the product quality and the waste of cost caused by inadequate reaction or too long reaction time can be avoided; by controlling the temperatures of the processing steps, the damages caused by side reactions are reduced as far as possible; by selecting the decoloring mode, an ideal, colorless and transparent liquid product can be obtained; and the product quality is above the national standard: especially the acid value is controlled to be about 0.2 while the acid value of the national standard is 1.0, and the stability of the product when stored for a long time is higher than those of the like products.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a preparation method of triethyl citrate. Background technique [0002] With the improvement of environmental protection awareness in various countries in the world, higher requirements are put forward for the main plasticizer of plastic products such as medicine and food packaging, daily necessities, toys and so on - dioctyl phthalate (DOP). However, due to the potential carcinogenic risk of DOP, corresponding measures have been taken internationally to limit the scope of use of DOP; the US Environmental Protection Agency has stopped plasticizing 6 types of phthalates according to the research results of the National Institute of Carcinogenesis. The Swiss government has decided to ban the use of DOP in children's toys; Germany has banned the use of DOP in all plastic products related to the human body and hygienic food; in Japan, DOP as a plastic additive is limited to...

Claims

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Application Information

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IPC IPC(8): C07C69/704C07C67/08
Inventor 张祖扬王劲松汪洪湖吴立军
Owner 蚌埠丰原涂山制药有限公司
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