Method for recovering and recycling L-tartaric acid

Abstract

The invention provides a method for recovering and recycling L-tartaric acid. The method comprises the following steps of: performing acidification and precipitation specific to waste water containing tartaric acid diammonium generated in a process for splitting racemic 4-methylsulfonylphenyl serine ethyl ester to form and separate a tartaric acid hydrogen ammonium salt; and acidizing and desalting to obtain a methanol solution of the L-tartaric acid. The method can be directly applied to the splitting process of racemic 4-methylsulfonylphenyl serine ethyl ester, and the recovery and recycling of the L-tartaric acid are realized. The method provided by the invention has mild reaction conditions and simple process operation, and the production cost of the splitting process can be greatly lowered.

Description

technical field

[0001] The invention relates to a method for recovering and recycling L-tartaric acid. Background technique

[0002] L-tartaric acid (L-tartaric acid), molecular formula: C4H606, molecular weight: 150.09, CAS number: 87-69-4. The product is colorless translucent crystal or white fine to coarse crystalline powder with sour taste.

[0003] L-tartaric acid (L-tartaric acid) is widely used as a sour agent in beverages and other foods, in wine, soft drinks, candy, bread, certain gelatinous sweets. Utilize its optical activity as a chemical resolution agent for the resolution of DL-aminobutanol in the manufacture of anti-tuberculosis drug intermediates; it can also be used as a chiral raw material for the synthesis of tartaric acid derivatives; use its acidity as a polyester fabric resin Finishing catalyst, PH regulator produced by oryzanol; using its complexing property, it can be used as complexing agent, masking agent, chelating agent, printing and dyeing anti...

Examples

Embodiment 1

[0023] (1) acidification precipitation: get the waste water 1000g (7wt% L-tartaric acid) containing diammonium tartrate that the p-thymphenyl phenylserine ethyl ester resolution process of racemization produces, be 45-50 ℃ at reaction temperature, with concentrated Hydrochloric acid was acidified to pH 3, and the reaction time was 0.5h. The reaction solution formed a precipitate of ammonium hydrogen tartrate and was filtered. The obtained precipitate was dried and dehydrated to obtain 66.5 g of ammonium hydrogen tartrate (85.3% recovery rate). L-ammonium hydrogen tartrate is an off-white solid with a purity greater than 99% and an optical purity of 100% as determined by HPLC.

[0024] (2) Acidification desalination: get the product ammonium hydrogen tartrate 33.4g obtained in the step (1), add 135g methyl alcohol, add the concentrated sulfuric acid of 10g, carry out acidification reaction. The reaction temperature is 42-45°C, and the reaction time is 2h. After the reaction,...

Embodiment 2

[0026] (1) Acidification precipitation: get the waste water 1000g (8wt% L-tartaric acid) containing the diammonium tartrate that the racemized p-thymphenylphenylserine ethyl ester resolution process produces, be 0 ℃ at reaction temperature, acidify with concentrated sulfuric acid To pH 2.5, the reaction time is 2h. The reaction solution formed a precipitate of ammonium hydrogen tartrate and was filtered. The obtained precipitate was dried and dehydrated to obtain 81.9 g of ammonium hydrogen tartrate (92.0% recovery). L-ammonium hydrogen tartrate is an off-white solid with a purity greater than 99% and an optical purity of 100% as determined by HPLC.

[0027] (2) acidification desalination: get the product ammonium hydrogen tartrate 33.4g of gained in the step (1), add 135g methyl alcohol, add 23.1g hydrochloric acid methanol solution (30%), carry out acidification reaction. The reaction temperature is 20-25°C, and the reaction time is 6h. After the reaction, the inorganic s...

Embodiment 3

[0029] (1) Acidification precipitation: get the waste water 1000g (10wt% L-tartaric acid) containing the diammonium tartrate that the racemized p-thymphenylphenylserine ethyl ester resolution process produces, be 25-30 ℃ at reaction temperature, with phosphoric acid Acidification to pH 4.0-4.5, the reaction time is 4h. The reaction solution formed a precipitate of ammonium hydrogen tartrate and was filtered. The obtained precipitate was dried and dehydrated to obtain 92.4 g of ammonium hydrogen tartrate (recovery rate: 83.0%). L-ammonium hydrogen tartrate is an off-white solid with a purity greater than 99% and an optical purity of 100% as determined by HPLC.

[0030] (2) acidification desalination: get the product ammonium hydrogen tartrate 33.4g obtained in the step (1), add 135g methyl alcohol, add 12g acetic acid, carry out acidification reaction. The reaction temperature is 0°C, and the reaction time is 10 h. After the reaction, the inorganic salts are removed by filtr...

technical field

[0001] The invention relates to a method for recovering and recycling L-tartaric acid. Background technique

[0002] L-tartaric acid (L-tartaric acid), molecular formula: C4H606, molecular weight: 150.09, CAS number: 87-69-4. The product is colorless translucent crystal or white fine to coarse crystalline powder with sour taste.

[0003] L-tartaric acid (L-tartaric acid) is widely used as a sour agent in beverages and other foods, in wine, soft drinks, candy, bread, certain gelatinous sweets. Utilize its optical activity as a chemical resolution agent for the resolution of DL-aminobutanol in the manufacture of anti-tuberculosis drug intermediates; it can also be used as a chiral raw material for the synthesis of tartaric acid derivatives; use its acidity as a polyester fabric resin Finishing catalyst, PH regulator produced by oryzanol; using its complexing property, it can be used as complexing agent, masking agent, chelating agent, printing and dyeing anti...

Examples

Embodiment 1

[0023] (1) acidification precipitation: get the waste water 1000g (7wt% L-tartaric acid) containing diammonium tartrate that the p-thymphenyl phenylserine ethyl ester resolution process of racemization produces, be 45-50 ℃ at reaction temperature, with concentrated Hydrochloric acid was acidified to pH 3, and the reaction time was 0.5h. The reaction solution formed a precipitate of ammonium hydrogen tartrate and was filtered. The obtained precipitate was dried and dehydrated to obtain 66.5 g of ammonium hydrogen tartrate (85.3% recovery rate). L-ammonium hydrogen tartrate is an off-white solid with a purity greater than 99% and an optical purity of 100% as determined by HPLC.

[0024] (2) Acidification desalination: get the product ammonium hydrogen tartrate 33.4g obtained in the step (1), add 135g methyl alcohol, add the concentrated sulfuric acid of 10g, carry out acidification reaction. The reaction temperature is 42-45°C, and the reaction time is 2h. After the reaction,...

Embodiment 2

[0026] (1) Acidification precipitation: get the waste water 1000g (8wt% L-tartaric acid) containing the diammonium tartrate that the racemized p-thymphenylphenylserine ethyl ester resolution process produces, be 0 ℃ at reaction temperature, acidify with concentrated sulfuric acid To pH 2.5, the reaction time is 2h. The reaction solution formed a precipitate of ammonium hydrogen tartrate and was filtered. The obtained precipitate was dried and dehydrated to obtain 81.9 g of ammonium hydrogen tartrate (92.0% recovery). L-ammonium hydrogen tartrate is an off-white solid with a purity greater than 99% and an optical purity of 100% as determined by HPLC.

[0027] (2) acidification desalination: get the product ammonium hydrogen tartrate 33.4g of gained in the step (1), add 135g methyl alcohol, add 23.1g hydrochloric acid methanol solution (30%), carry out acidification reaction. The reaction temperature is 20-25°C, and the reaction time is 6h. After the reaction, the inorganic s...

Embodiment 3

[0029] (1) Acidification precipitation: get the waste water 1000g (10wt% L-tartaric acid) containing the diammonium tartrate that the racemized p-thymphenylphenylserine ethyl ester resolution process produces, be 25-30 ℃ at reaction temperature, with phosphoric acid Acidification to pH 4.0-4.5, the reaction time is 4h. The reaction solution formed a precipitate of ammonium hydrogen tartrate and was filtered. The obtained precipitate was dried and dehydrated to obtain 92.4 g of ammonium hydrogen tartrate (recovery rate: 83.0%). L-ammonium hydrogen tartrate is an off-white solid with a purity greater than 99% and an optical purity of 100% as determined by HPLC.

[0030] (2) acidification desalination: get the product ammonium hydrogen tartrate 33.4g obtained in the step (1), add 135g methyl alcohol, add 12g acetic acid, carry out acidification reaction. The reaction temperature is 0°C, and the reaction time is 10 h. After the reaction, the inorganic salts are removed by filtr...

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