CN111087373A - Method for preparing vitamin C by acid method - Google Patents
Method for preparing vitamin C by acid method Download PDFInfo
- Publication number
- CN111087373A CN111087373A CN201911385497.2A CN201911385497A CN111087373A CN 111087373 A CN111087373 A CN 111087373A CN 201911385497 A CN201911385497 A CN 201911385497A CN 111087373 A CN111087373 A CN 111087373A
- Authority
- CN
- China
- Prior art keywords
- acid
- vitamin
- hydrochloric acid
- gulonic acid
- gulonic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
- C07D307/56—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D307/62—Three oxygen atoms, e.g. ascorbic acid
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the technical field of chemical synthesis, and particularly discloses a method for preparing vitamin C by an acid method. The method for preparing the vitamin C by the acid method takes 2-keto-L-gulonic acid as a raw material, adopts hydrochloric acid or the combination of the hydrochloric acid and sulfuric acid as a catalyst, and prepares the vitamin C by catalytic reaction. The method provided by the invention does not need to introduce hydrogen chloride gas or add organic solvent, has mild reaction conditions, greatly simplifies the production process, reduces the corrosion of production equipment caused by using high-concentration hydrochloric acid, and reduces the requirement on the equipment. The preparation method provided by the invention is simple to operate, shortens the production period, reduces the consumption of chemicals and the generation of waste, reduces the production cost, and realizes green production and circular economy.
Description
Technical Field
The invention relates to the technical field of chemical synthesis, in particular to a method for preparing vitamin C by an acid method, and specifically relates to a method for preparing vitamin C by using gulonic acid as a raw material.
Background
Vitamin C is a polyhydroxy compound, two of which are at the 2-and 3-positions in the moleculeThe adjacent enol-type hydroxyl group is easy to dissociate and release H+Therefore, it has the property of acid, also called ascorbic acid. Vitamin C has strong reducibility, is easily oxidized into dehydrovitamin C, and has the same physiological function. However, if dehydrovitamin C is oxidized continuously, the physiological efficacy of the dehydrovitamin C is completely lost after the dehydrovitamin C is generated into diketogulonic acid.
The existing industrial production process of vitamin C is a two-step fermentation method, which comprises fermentation, extraction and conversion processes. The conversion process is divided into acid conversion method and alkali conversion method according to the structural characteristics of 2-keto-L-gulonic acid. The alkali conversion method has the problems of complicated operation, large waste liquid amount, high cost and low yield. The traditional acid conversion method is to take gulonate as a raw material to react with inorganic acid under certain conditions to generate vitamin C. For example, chinese patent application publication No. CN104693160A discloses using gulonate or gulonic acid as a raw material, mixing with concentrated hydrochloric acid, and introducing hydrogen chloride gas to increase the hydrochloric acid concentration for reaction. The method adds a hydrogen chloride gas desorption process, has complex operation and extremely strict requirements on equipment. Therefore, the process has the defects of high operation difficulty and large equipment investment in industrial production.
Disclosure of Invention
The invention mainly solves the technical problem of providing a method for preparing vitamin C by an acid method, so as to simplify the process operation steps, reduce the operation difficulty and be more suitable for industrial production.
In order to solve the technical problems, the invention adopts a technical scheme that: a method for preparing vitamin C by an acid method comprises the following steps: the vitamin C is prepared by taking 2-keto-L-gulonic acid as a raw material and hydrochloric acid as a catalyst through catalytic reaction.
Preferably, the mass percentage concentration of the catalyst hydrochloric acid is 20-40%, and preferably 20-37.5%.
Preferably, sulfuric acid can be further added into the catalyst hydrochloric acid, and the mass percentage concentration of the sulfuric acid is 40-98.5%, preferably 50-98%. The content of hydrogen ions in a reaction system can be improved by adding a small amount of sulfuric acid, so that the conversion rate of the vitamin C is further improved.
Preferably, the mass of the sulfuric acid added to the hydrochloric acid is 0 to 30% of the mass of the hydrochloric acid, and preferably 0.8 to 30%.
Preferably, the mass ratio of the raw material 2-keto-L-gulonic acid to the hydrochloric acid is 0.05-3: 1, and more preferably 0.1-2: 1.
Preferably, the reaction temperature is 20-100 ℃, preferably 40-95 ℃.
Preferably, the starting material 2-keto-L-gulonic acid is prepared from a salt of gulonic acid obtained by fermentation or other means, and more preferably the salt of gulonic acid is prepared into 2-keto-L-gulonic acid by ion exchange (ion exchange) or chemical reaction; the gulonic acid salt is any one or more of sodium gulonic acid, calcium gulonic acid, potassium gulonic acid and magnesium gulonic acid, and is further preferably sodium gulonic acid and/or calcium gulonic acid.
The method for preparing vitamin C by the acid method also comprises an extraction and refining step, when sulfuric acid is not added in the catalyst, namely only hydrochloric acid is used as the catalyst, the extraction and refining step is as follows: carrying out solid-liquid separation on the material prepared by the catalytic reaction to obtain vitamin C coarse crystals and filtrate; concentrating, cooling and crystallizing the filtrate to obtain crude vitamin C, dissolving, decolorizing, cooling and crystallizing the obtained crude vitamin C to obtain a pure vitamin C product; the obtained vitamin C coarse crystal is dissolved, decolored, cooled and crystallized to prepare the pure vitamin C product.
The method for preparing vitamin C by the acid method also comprises an extraction and refining step, when sulfuric acid is added into a catalyst, namely a catalyst system of sulfuric acid and hydrochloric acid is adopted, and the extraction and refining step is as follows: carrying out solid-liquid separation on the material prepared by the catalytic reaction to obtain vitamin C coarse crystals and filtrate; dissolving, decoloring, cooling and crystallizing the obtained vitamin C coarse crystal to prepare a pure vitamin C product; adding a calcium-containing reagent into the filtrate to neutralize and remove sulfuric acid, filtering and removing calcium sulfate precipitate, and decoloring and ion-exchanging the obtained neutralized liquid to extract vitamin C, or using the neutralized liquid to prepare a vitamin C derivative; the calcium-containing reagent is calcium carbonate, calcium oxide or calcium hydroxide.
Preferably, the reaction employs a batch tank reactor, a semi-continuous tank reactor, or a continuous reactor.
The method for preparing vitamin C by the acid method provided by the invention relates to a reaction equation as follows:
the invention relates to a method for preparing vitamin C by a novel acid method, which takes 2-keto-L-gulonic acid as a raw material and takes hydrochloric acid or the combination of hydrochloric acid and sulfuric acid as a catalyst to generate the vitamin C by catalytic conversion. The solution containing vitamin C obtained by the reaction is extracted and refined to obtain the pure vitamin C product.
The method provided by the invention does not need to introduce hydrogen chloride gas or add organic solvent, has mild reaction conditions, greatly simplifies the production process, avoids or lightens the corrosion of production equipment caused by using high-concentration hydrochloric acid, and reduces the requirement on the equipment. In the actual production, the hydrochloric acid can be recycled in an evaporation and concentration mode, and the waste liquid discharge pollution is reduced. The sulfuric acid is also recycled in the form of calcium sulfate by-products, so that the generation of wastes is greatly reduced.
The preparation method provided by the invention is simple to operate, shortens the production period, reduces the consumption of chemicals and the generation of waste, reduces the production cost, and realizes green production and circular economy.
The operations involved in the present invention are conventional in the art unless otherwise specified, and the separation apparatus involved may be one well known in the art.
Detailed Description
Preferred embodiments of the present invention will be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the spirit and scope of this invention.
The following examples all used the starting materials represented by the formula (I).
Example 1
40g of gulonic acid (purity 98.5%) solid shown in formula (I) and 60g of concentrated hydrochloric acid (concentration 37.21%, w/w) are weighed in a reaction bottle in sequence, put into a water bath kettle at 80 ℃, and dissolved by magnetic stirring for catalytic reaction. Through analysis, detection and calculation, when the reaction is carried out for 30min, the conversion rate of the gulonic acid reaches 92.21 percent.
Stopping reaction, and extracting and refining to obtain pure vitamin C.
Example 2
40g of gulonic acid (purity 97%) solid shown in formula (I) and 50g of hydrochloric acid (concentration 37%, w/w) are weighed in a reaction bottle in sequence, slowly stirred, and 10g of concentrated sulfuric acid (concentration 98%, w/w) is dropwise added into the reaction bottle, wherein the mass of the sulfuric acid accounts for 20% of that of the hydrochloric acid solution. After the dropwise addition, the mixture is moved to a water bath kettle at 80 ℃, and is stirred by magnetic force to carry out dissolution and catalytic reaction. By analysis detection and calculation, the conversion rate is 97.79 percent when the reaction is carried out for 30 min.
Stopping reaction, and extracting and refining to obtain pure vitamin C.
Example 3
3002g of gulonic acid (98.39%) solid shown in formula (I) and 3026g of hydrochloric acid (37%, w/w) were sequentially weighed and placed in a 10L glass reactor, mechanical stirring was started, the feed liquid was heated to 45 ℃ by circulating jacket water, and a timed reaction was started. After the reaction is carried out for 22 hours, the heating is stopped and the discharging is carried out, and solid liquid containing vitamin C is obtained. Cooling and crystallizing for about 4 hours at room temperature, centrifugally separating the crude vitamin C and the filtrate, and respectively detecting the vitamin C content. The conversion rate of vitamin C obtained in this example was 93.71% by detection calculation.
Example 4
30.12g of gulonic acid (96.57%) solid represented by formula (I) and 60.06g of hydrochloric acid (37%, w/w) were weighed in sequence into a reaction flask, and 2.12g of concentrated sulfuric acid (98%, w/w) was added dropwise to the reaction flask while stirring, at this time, the mass of sulfuric acid was 3.5% of the mass of the hydrochloric acid solution. After the dropwise addition, the mixture is moved to a water bath kettle at 70 ℃, and is stirred by magnetic force to carry out dissolution and catalytic reaction. Through detection and calculation, the conversion rate is 97.28% when the reaction is carried out for 75 min.
Example 5
30.20g of gulonic acid (98.68%) solid shown in formula (I) and 60.39g of industrial hydrochloric acid (32.02%, w/w) are sequentially weighed into a reaction bottle, the reaction bottle is placed into a water bath kettle at 80 ℃ for heating, and stirring reaction is carried out by utilizing magnetic force. After the reaction is carried out for 35min, the heating is stopped, and a parallel sample is taken to detect the content of the vitamin C. Through detection calculation, the theoretical VC% in the embodiment is 29.84%, and the detection results of the parallel samples are 26.22% and 26.76%, respectively, and belong to the titration error range. The average titer was taken to be 26.49% and the conversion at this point was calculated to be 88.77%.
Example 6
Preparing three sections of tetrafluoro tubules with the same length and diameter, respectively weighing 10g of gulonic acid (88.55%) solid shown in formula (I) in the tubules, sealing one end of the tetrafluoro tubule and numbering No. 1-No. 3 tubules in sequence. 14.32g of high purity water was added into tube 1, mixed with the gulonic acid solid and then 0.67g of hydrochloric acid solution (37%, w/w) was added dropwise; 13.66g of pure water is added into the No. 2 tube, and then 1.36g of hydrochloric acid solution (37 percent, w/w) is added dropwise; also, 12.3g of pure water and 2.69g of hydrochloric acid (37%, w/w) were added to tube 3. Sealing two ends of the tetrafluoride tube, and putting 3 tubes into a water bath kettle at 100 ℃ simultaneously for reaction for 70 min. After the reaction is finished, the mixture is placed in cold water and stands for about 10min, the thin tube is taken out, the feed liquid is poured out, pure water is added for dilution, the inner wall of the pipeline is cleaned, and the dilution times are counted.
Through detection and calculation, the conversion rate of vitamin C of the pipeline No. 1 in the embodiment is 44.4%; the conversion of line 2 was 44.9%; the conversion rate of the pipeline 3 reaches 45.5 percent. The mass ratio of the gulonic acid to the hydrochloric acid in the tubes 1-3 in the example is 14.93:1, 7.35:1 and 3.72:1 respectively; and the conversion rate is not high due to dilution of the hydrochloric acid concentration by adding a large amount of pure water.
The scheme is simulated by referring to the structural principle of a pipeline reactor, mainly considers the change of the conversion rate of gulonic acid and hydrochloric acid under different mass ratios, and shows that the method has great improvement and optimization space to improve the conversion rate of vitamin C.
Example 7
7.52g of gulonic acid (96.57%) solid shown in formula (I) and 60.19g of hydrochloric acid (37%, w/w) are sequentially weighed into a 250ml glass reaction bottle, placed into a 60 ℃ water bath kettle and heated, and stirred by magnetic force for reaction. When the reaction is carried out for 120min, sampling, detecting and analyzing the content of the vitamin C. The conversion rate of the obtained vitamin C is 98.25 percent by detection calculation.
Example 8
100.13g of gulonic acid (97.75%) solid of formula (I) and 101.21g of hydrochloric acid (37%, w/w) were weighed out in sequence into a 500ml glass reaction flask, and 7.74g of concentrated sulfuric acid (98%, w/w) was slowly added dropwise into the reaction flask while stirring, at this time the mass of sulfuric acid was 7.65% of the mass of the hydrochloric acid solution. The reaction bottle is put into a water bath kettle at 44 ℃ for heating, and stirring reaction is carried out by utilizing magnetic force. After the reaction proceeded for 24 hours, the heating was stopped. And adding a certain amount of high-purity water into the reaction bottle to dissolve the solid precipitated by the reaction, and sampling and analyzing the vitamin C content in the liquid after the solid is completely dissolved. The conversion rate of vitamin C obtained in this example was 94.58% according to detection calculation.
Example 9
3499.2g of gulonic acid (97.43%) solid shown in formula (I), 1997.8g of hydrochloric acid (37%, w/w) and 198.72g of sulfuric acid (98%, w/w) are weighed in sequence, put into a 10L glass reactor, mechanically stirred, and the material liquid is heated to 45 ℃ by using jacket water circulation, and a timed reaction is started. After the reaction is carried out for 20 hours, the heating is stopped and the discharging is carried out, so as to obtain solid liquid containing vitamin C. Cooling and crystallizing for about 3 hours at room temperature, centrifugally separating the crude vitamin C crystal and the filtrate, and respectively detecting the vitamin C content. The conversion rate of vitamin C obtained in this example was 91.97% by detection calculation.
Example 10
40g of gulonic acid (88.55%) solid of formula (I) and 56g of hydrochloric acid (37%, w/w) were weighed in sequence into a 250ml glass reaction flask, and 4g of concentrated sulfuric acid (50%, w/w) was added dropwise with stirring, at which time the mass of sulfuric acid was about 7% of the mass of the hydrochloric acid solution. And (3) putting the reaction bottle into a water bath kettle at 80 ℃ for heating, and stirring and reacting by using magnetic force. When the reaction proceeded for 45min, a sample was taken to analyze the vitamin C content in the solution. The conversion rate of vitamin C obtained in this example was 90.34% according to detection calculation.
Comparative example
Comparative tests were also conducted in the present invention. The details are as follows.
As shown in Table 1 below, 2-keto-L-gulonic acid (gulonic acid represented by formula (I)) having a purity of 98.35% was used as a raw material, and 37% (w/w) hydrochloric acid and 98% (w/w) sulfuric acid solution were used as catalysts, and experimental comparisons were made at the same reaction temperature, respectively.
In the table, experiment 1 uses only hydrochloric acid as the catalyst, and experiment 2 uses a combination of hydrochloric acid and sulfuric acid as the catalyst. Specific experimental data are shown in table 1.
TABLE 1
As can be seen from the above table, the conversion rate of experiment 2 catalyzed by adding sulfuric acid is higher than that of experiment 1 catalyzed by hydrochloric acid alone under the condition that the mass ratio of 2-keto-L-gulonic acid to hydrochloric acid is the same. The two methods are respectively beneficial, and the method expressed by the experiment 1 has simple process steps and strong operability; the process of experiment 2 has a significantly higher conversion. In the traditional acid method, a method of adding a solvent or an active agent is also adopted to improve the solubility of the 2-keto-L-gulonic acid so as to enhance the vitamin C conversion effect. The invention can increase H in the reaction system by adding sulfuric acid+The concentration achieves the effect of improving the conversion rate, and a solvent is not adopted, so that the difficulty of a subsequent VC extraction process can be reduced, and the treatment steps of solvent recycling are also reduced.
According to the results, the method provided by the invention has the advantages of wide raw material proportion and reaction temperature regulation range, strong flexibility of conversion reaction conditions, stable conversion rate and capability of performing step-by-step optimization improvement according to actual production cost control and production conditions. The invention effectively simplifies the process flow of the traditional acid method for preparing the vitamin C, lightens the corrosion of high-concentration acid to production equipment and reduces the requirements on industrial equipment. The method is simple to operate, obviously shortens the production period, reduces the consumption of chemicals and the generation of waste, reduces the production cost, and realizes green production and circular economy.
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. A method for preparing vitamin C by an acid method is characterized by comprising the following steps: the vitamin C is prepared by taking 2-keto-L-gulonic acid as a raw material and hydrochloric acid as a catalyst through catalytic reaction.
2. The preparation method according to claim 1, wherein the concentration of the catalyst hydrochloric acid is 20 to 40% by mass, preferably 20 to 37.5% by mass.
3. The preparation method according to claim 1 or 2, characterized in that sulfuric acid is further added to the catalyst hydrochloric acid, and the mass percentage concentration of the sulfuric acid is 40-98.5%, preferably 50-98%.
4. The production method according to claim 3, wherein the mass of the sulfuric acid added to the hydrochloric acid is 0 to 30% of the mass of the hydrochloric acid, and preferably 0.8 to 30%.
5. The preparation method according to any one of claims 1 to 4, wherein the mass ratio of the raw material 2-keto-L-gulonic acid to the hydrochloric acid is 0.05 to 3:1, preferably 0.1 to 2: 1.
6. The method according to claim 5, wherein the reaction temperature is 20 to 100 ℃, preferably 40 to 95 ℃.
7. The method of claim 6, wherein the starting 2-keto-L-gulonic acid is prepared from a salt of gulonic acid, preferably from a salt of gulonic acid by ion exchange or chemical reaction to produce 2-keto-L-gulonic acid;
the gulonic acid salt is any one or more of sodium gulonic acid, calcium gulonic acid, potassium gulonic acid and magnesium gulonic acid, and is preferably sodium gulonic acid and/or calcium gulonic acid.
8. The method of claim 7, further comprising the steps of: carrying out solid-liquid separation on the material prepared by the catalytic reaction to obtain vitamin C coarse crystals and filtrate; concentrating, cooling and crystallizing the filtrate to obtain crude vitamin C, dissolving, decolorizing, cooling and crystallizing the obtained crude vitamin C to obtain a pure vitamin C product; the obtained vitamin C coarse crystal is dissolved, decolored, cooled and crystallized to prepare the pure vitamin C product.
9. The method of claim 7, further comprising the steps of: carrying out solid-liquid separation on the material prepared by the catalytic reaction to obtain vitamin C coarse crystals and filtrate; dissolving, decoloring, cooling and crystallizing the obtained vitamin C coarse crystal to prepare a pure vitamin C product; adding a calcium-containing reagent into the filtrate to neutralize and remove sulfuric acid, filtering and removing calcium sulfate precipitate, and decoloring and ion-exchanging the obtained neutralized liquid to extract vitamin C, or using the neutralized liquid to prepare a vitamin C derivative; the calcium-containing reagent is calcium carbonate, calcium oxide or calcium hydroxide.
10. The production method according to claim 8 or 9, wherein the reaction employs a batch tank reactor, a semi-continuous tank reactor, or a continuous reactor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911385497.2A CN111087373A (en) | 2019-12-29 | 2019-12-29 | Method for preparing vitamin C by acid method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911385497.2A CN111087373A (en) | 2019-12-29 | 2019-12-29 | Method for preparing vitamin C by acid method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111087373A true CN111087373A (en) | 2020-05-01 |
Family
ID=70397543
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911385497.2A Pending CN111087373A (en) | 2019-12-29 | 2019-12-29 | Method for preparing vitamin C by acid method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111087373A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114369075A (en) * | 2022-02-14 | 2022-04-19 | 河北乐开节能科技股份有限公司 | Method for preparing VC crystals in one step by using aqueous solution of 2-keto-L-gulonic acid |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1265655A (en) * | 1997-08-07 | 2000-09-06 | 默克专利股份有限公司 | Process for preparing L-ascorbic acid |
| US20020151726A1 (en) * | 2000-12-22 | 2002-10-17 | Arumugam Bhaskar Krishna | Continuous process for producing L-ascorbic acid |
| CN102382084A (en) * | 2011-09-21 | 2012-03-21 | 石家庄开发区德赛化工有限公司 | Method for producing vitamin C |
| CN103087018A (en) * | 2012-11-14 | 2013-05-08 | 江苏江山制药有限公司 | Preparation method of erythorbic acid |
| CN104693160A (en) * | 2015-02-16 | 2015-06-10 | 安徽泰格生物技术股份有限公司 | Preparation method of vitamin C |
-
2019
- 2019-12-29 CN CN201911385497.2A patent/CN111087373A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1265655A (en) * | 1997-08-07 | 2000-09-06 | 默克专利股份有限公司 | Process for preparing L-ascorbic acid |
| US20020151726A1 (en) * | 2000-12-22 | 2002-10-17 | Arumugam Bhaskar Krishna | Continuous process for producing L-ascorbic acid |
| CN1507440A (en) * | 2000-12-22 | 2004-06-23 | �Ϻ���ͨ��ѧ | Continuous process for producing L-ascorbic acid |
| CN102382084A (en) * | 2011-09-21 | 2012-03-21 | 石家庄开发区德赛化工有限公司 | Method for producing vitamin C |
| CN103087018A (en) * | 2012-11-14 | 2013-05-08 | 江苏江山制药有限公司 | Preparation method of erythorbic acid |
| CN104693160A (en) * | 2015-02-16 | 2015-06-10 | 安徽泰格生物技术股份有限公司 | Preparation method of vitamin C |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114369075A (en) * | 2022-02-14 | 2022-04-19 | 河北乐开节能科技股份有限公司 | Method for preparing VC crystals in one step by using aqueous solution of 2-keto-L-gulonic acid |
| CN114369075B (en) * | 2022-02-14 | 2023-09-29 | 河北乐开节能科技股份有限公司 | Method for preparing VC crystal by using aqueous solution of 2-keto-L-gulonic acid in one step |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112390841B (en) | Purification method of progesterone | |
| US3944606A (en) | Process of producing alkali metal or ammonium citrates | |
| EP2744489A1 (en) | Process for manufacturing hmb and salts thereof | |
| CN111087373A (en) | Method for preparing vitamin C by acid method | |
| CN112876527B (en) | Treatment method of prednisone acetate mother liquor | |
| CN110317133A (en) | The water phase refining methd of long-chain biatomic acid in bio-fermented liquid | |
| CN111559995B (en) | Preparation process of ascorbic acid ethyl ether | |
| EP4148061A1 (en) | Post-treatment method of sucrose-6-carboxylic ester chlorination reaction liquid | |
| CN103288890B (en) | One prepares 3-O-benzyl-1, the new method of 2-O-isopropylidene-β-L-furan idose | |
| CN1050356C (en) | Process for preparing sodium (or potassium) L-ascorbate | |
| CN108220625B (en) | Method for recovering lithium from lithium-containing waste liquid | |
| CN109574047A (en) | The method of high-purity Sustiva and lithium chloride is recycled from medicine waste liquid containing lithium | |
| CN104961787A (en) | Synthetic method for cordycepin | |
| CN108948114B (en) | Impurity removal method applied to 9- (E) -erythromycin oxime | |
| CN111233651A (en) | Method for recovering and preparing L (+) -2, 3-dihydroxysuccinic acid from polybara production wastewater | |
| CN111574416A (en) | Method for preparing tiamulin from isothiourea salt and pleuromutilin p-methylbenzenesulfonate | |
| CN106496220B (en) | A kind of preparation method of lysergol | |
| EP3041816B1 (en) | Lactate production process | |
| LU501486B1 (en) | Method for recovering chlorine and preparing chlorine salt based on solvent extraction and salting-out effect integration technology | |
| CN113979901B (en) | Preparation method of C5 acetal sulfone | |
| CN108752180B (en) | Method for preparing 1-chloroanthraquinone by direct chlorination of photocatalytic chlorine | |
| CN108264530A (en) | 20,23- dihalo -5-O- mycamino syl-tylono lides and its synthetic method and application | |
| CN114014761A (en) | Method for separating o-nitrobenzoic acid based on esterification | |
| CN118146286A (en) | Preparation method of dehydronandrolone acetate | |
| CN116874446A (en) | Synthesis process of 3- (N-morpholinyl) -2-hydroxy sodium propane sulfonate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200501 |
|
| RJ01 | Rejection of invention patent application after publication |