Method for recovering L-tartaric acid from D-cysteine conversion hydrolysate

Abstract

The invention provides a method for recovering L-tartaric acid from D-cysteine conversion hydrolysate. The method comprises the following steps of: 1, hydrolysis and neutralization of double salt, specifically, separating L-tartaric acid from the D-cysteine conversion hydrolysate by using calcium oxide as a precipitator; 2, acidizing treatment, specifically, namely acidizing the L-calcium tartrate with sulfuric acid, performing concentrating, performing filtering to remove calcium sulfate, and cooling and crystallizing filtrate to obtain L-tartaric acid; and 3, product preparation, ,specifically, preparing D-cystine by taking liquid obtained after the L-tartaric acid is recycled as the raw material and adopting a D-cysteine asymmetric synthesis process in the prior art. According to the method, the L-tartaric acid in the D-cysteine conversion hydrolysate is separated by using the calcium oxide as a precipitator. Compared with a method in the prior art, the method has a higher recovery rate which can reach 76%; the application of the L-tartaric acid in the process is realized; the process route for preparing the D-cystine is optimized; the purpose of recovering and recycling the L-tartaric acid is achieved; and the production cost is reduced.

Description

technical field

[0001] The invention relates to the technical field of bioengineering, in particular to a method for recovering mechanically applied L-tartaric acid from D-cysteine ​​conversion hydrolyzate. Background technique

[0002] L-tartaric acid is colorless translucent crystal or white fine to coarse crystalline powder, sour taste, molecular formula: C 4 h 6 o 6 , molecular weight: 150.09, CAS number: 87-69-4. L-tartaric acid is often used as a sour agent in various beverages, such as wine, soft drinks, candy, bread and some colloidal sweets, and L-tartaric acid is also commonly used as a chemical resolution agent to prepare various optical isomers. In the asymmetric synthesis of D-cysteine, a large amount of L-tartaric acid exists in the converted hydrolyzate.

[0003] D-cysteine ​​is the enantiomer of L-cysteine, molecular formula: C 3 h 7 NO 2 S, molecular weight: 121.16, CAS number: 921-01-7, is a synthetic product. D-cysteine ​​is an important synthetic ...

Examples

Embodiment 1

[0028] The method for reclaiming L-tartaric acid from D-cysteine ​​conversion hydrolyzate, described method is carried out according to the following steps:

[0029] 1. Hydrolysis and neutralization of double salts: Add 600 mL of purified water to 311 g of solid (S)-2,2-dimethyltetrahydrothiazole-4-carboxylic acid L-tartaric acid, hydrolyze at a constant temperature of 60°C for 1.0 hour, and cool down to 40°C, slowly add 56 g of calcium oxide to the hydrolyzate for neutralization, the temperature is controlled between 30 and 50°C, continue to stir for 1 hour after the calcium oxide is added, control the pH = 2.8, and stir at a constant temperature of 40°C for 1 hour, Then filter, dry under negative pressure, rinse the precipitate with 200 mL of purified water three times, and dry at 70°C for 6 hours to obtain 166 g of L-calcium tartrate with a yield of 88.3%. Repeat this step, the yield is 89.5%, and a sufficient amount of L-calcium tartrate is prepared.

[0030] 2. Acidifica...

Embodiment 2

[0033] The method for reclaiming L-tartaric acid from D-cysteine ​​conversion hydrolyzate, described method is carried out according to the following steps:

[0034]1. Hydrolysis and neutralization of double salt: put 500 g of solid (S)-2, 2-dimethyltetrahydrothiazole-4-carboxylic acid L-tartaric acid in a 2000 mL beaker, add 965 mL of purified water, and heat up to 60°C Hydrolyze for 2 hours, then lower the temperature to 40°C, slowly add 95 g of calcium oxide to the hydrolyzate for neutralization, keep the temperature between 30 and 50°C, continue to stir at 40°C for 1 hour after adding calcium oxide, and control the pH = 3.0, then filtered, vacuum-dried, the precipitate was rinsed three times with 300 mL of pure water, 100 mL each time, and dried at 80°C for 5 hours to obtain 270 g of L-calcium tartrate with a yield of 89.3%. Repeat this step, the yield is 88.1%, and a sufficient amount of L-calcium tartrate is prepared.

[0035] 2. Acidification treatment: Take 300 g of L...

Embodiment 3

[0038] The method for reclaiming L-tartaric acid from D-cysteine ​​conversion hydrolyzate, described method is carried out according to the following steps:

[0039] 1. Hydrolysis and neutralization of double salt: Take 600 g of solid (S)-2, 2-dimethyltetrahydrothiazole-4-carboxylic acid L-tartaric acid in a 2000 mL beaker, add 1200 mL of purified water, stir, and heat up to Hydrolyze at 70°C for 2.0 hours, then lower the temperature to 40°C, slowly add 115 g of calcium oxide to the hydrolyzate for neutralization, control the neutralization temperature between 30 and 50°C, continue stirring for 2 hours after adding calcium oxide, and control the pH is 3.0. Then filter, dry under negative pressure, rinse the precipitate with 360 mL of purified water three times, 120 mL each time, and dry at 80°C for 8 hours to obtain 330 g of L-calcium tartrate with a yield of 91.0%.

[0040] 2. Acidification treatment: Take 300 g of L-calcium tartrate, add 600 mL of water, stir, raise the tem...

technical field

[0001] The invention relates to the technical field of bioengineering, in particular to a method for recovering mechanically applied L-tartaric acid from D-cysteine ​​conversion hydrolyzate. Background technique

[0002] L-tartaric acid is colorless translucent crystal or white fine to coarse crystalline powder, sour taste, molecular formula: C 4 h 6 o 6 , molecular weight: 150.09, CAS number: 87-69-4. L-tartaric acid is often used as a sour agent in various beverages, such as wine, soft drinks, candy, bread and some colloidal sweets, and L-tartaric acid is also commonly used as a chemical resolution agent to prepare various optical isomers. In the asymmetric synthesis of D-cysteine, a large amount of L-tartaric acid exists in the converted hydrolyzate.

[0003] D-cysteine ​​is the enantiomer of L-cysteine, molecular formula: C 3 h 7 NO 2 S, molecular weight: 121.16, CAS number: 921-01-7, is a synthetic product. D-cysteine ​​is an important synthetic ...

Examples

Embodiment 1

[0028] The method for reclaiming L-tartaric acid from D-cysteine ​​conversion hydrolyzate, described method is carried out according to the following steps:

[0029] 1. Hydrolysis and neutralization of double salts: Add 600 mL of purified water to 311 g of solid (S)-2,2-dimethyltetrahydrothiazole-4-carboxylic acid L-tartaric acid, hydrolyze at a constant temperature of 60°C for 1.0 hour, and cool down to 40°C, slowly add 56 g of calcium oxide to the hydrolyzate for neutralization, the temperature is controlled between 30 and 50°C, continue to stir for 1 hour after the calcium oxide is added, control the pH = 2.8, and stir at a constant temperature of 40°C for 1 hour, Then filter, dry under negative pressure, rinse the precipitate with 200 mL of purified water three times, and dry at 70°C for 6 hours to obtain 166 g of L-calcium tartrate with a yield of 88.3%. Repeat this step, the yield is 89.5%, and a sufficient amount of L-calcium tartrate is prepared.

[0030] 2. Acidifica...

Embodiment 2

[0033] The method for reclaiming L-tartaric acid from D-cysteine ​​conversion hydrolyzate, described method is carried out according to the following steps:

[0034]1. Hydrolysis and neutralization of double salt: put 500 g of solid (S)-2, 2-dimethyltetrahydrothiazole-4-carboxylic acid L-tartaric acid in a 2000 mL beaker, add 965 mL of purified water, and heat up to 60°C Hydrolyze for 2 hours, then lower the temperature to 40°C, slowly add 95 g of calcium oxide to the hydrolyzate for neutralization, keep the temperature between 30 and 50°C, continue to stir at 40°C for 1 hour after adding calcium oxide, and control the pH = 3.0, then filtered, vacuum-dried, the precipitate was rinsed three times with 300 mL of pure water, 100 mL each time, and dried at 80°C for 5 hours to obtain 270 g of L-calcium tartrate with a yield of 89.3%. Repeat this step, the yield is 88.1%, and a sufficient amount of L-calcium tartrate is prepared.

[0035] 2. Acidification treatment: Take 300 g of L...

Embodiment 3

[0038] The method for reclaiming L-tartaric acid from D-cysteine ​​conversion hydrolyzate, described method is carried out according to the following steps:

[0039] 1. Hydrolysis and neutralization of double salt: Take 600 g of solid (S)-2, 2-dimethyltetrahydrothiazole-4-carboxylic acid L-tartaric acid in a 2000 mL beaker, add 1200 mL of purified water, stir, and heat up to Hydrolyze at 70°C for 2.0 hours, then lower the temperature to 40°C, slowly add 115 g of calcium oxide to the hydrolyzate for neutralization, control the neutralization temperature between 30 and 50°C, continue stirring for 2 hours after adding calcium oxide, and control the pH is 3.0. Then filter, dry under negative pressure, rinse the precipitate with 360 mL of purified water three times, 120 mL each time, and dry at 80°C for 8 hours to obtain 330 g of L-calcium tartrate with a yield of 91.0%.

[0040] 2. Acidification treatment: Take 300 g of L-calcium tartrate, add 600 mL of water, stir, raise the tem...