CN101747218B - Method for removing impurities in glycine synthetic process - Google Patents
Method for removing impurities in glycine synthetic process Download PDFInfo
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- CN101747218B CN101747218B CN 200810239718 CN200810239718A CN101747218B CN 101747218 B CN101747218 B CN 101747218B CN 200810239718 CN200810239718 CN 200810239718 CN 200810239718 A CN200810239718 A CN 200810239718A CN 101747218 B CN101747218 B CN 101747218B
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Abstract
The invention provides a method for removing impurities in glycine reaction liquid and mother liquid in a glycine preparing process by using a glycolonitrile method. The method comprises the following steps: carrying out independent backflow to alkaline hydrolysis synthetic liquid after alkaline hydrolysis is finished or mixing the glycine mother liquid and liquid alkaline synthetic liquid and then carrying out the alkaline hydrolysis; carrying out intermittent or continuous production under high-temperature backflow; and finally removing the impurities.
Description
Technical field
The present invention relates to by organic impurity and inorganic impurity ammonium sulfate such as the acid amides in removal glycine reactant liquid and the mother liquor in the technological process of hydroxyl nitrile compounds production glycine, peptides, precipitate wherein foreign pigment, but and the method for the glycine product in the efficient recovery glycin mother liquid and by-product iminodiethanoic acid.Be characterized in the alkali solution liquid of glycine and mother liquor under stronger strong alkaline condition, back flow reaction, can make the condensess such as wherein most of acid amides, peptide be hydrolyzed into product glycine, iminodiethanoic acid etc., and make the contaminant filters such as wherein a large amount of polymerization carbonizing matters, metal complex and remove, ammonium sulfate is converted into by-product sodium sulfate.Like this, by processing and Optimizing Technical, not only can improve the conversion of raw material and the yield of product, thereby and the content that can reduce coloring matter reduce the consumption of bleaching workshop section gac, for the aftertreatments such as desalination, crystallization provide colory reaction solution.
Background technology
Ying Li company of Qing Hua Ziguang is through deep research, invention prepares the patent operational path of glycine with operations such as the direct ammonification of hydroxyacetonitrile, alkaline hydrolysis, deamination, acidifying, decolouring, concentrated and purifying, the recovery of inorganic salt and the yield of raising glycine have been found, suppress the generation of iminodiethanoic acid, the applying mechanically and easier separation and purification and clean preparation method of mother liquor.
Because the hydrolysis reaction of nitriles substance just can be finished at low temperatures, so temperature of reaction generally all is controlled under the lower temperature on producing, but do not consider itrile group and the amino problems such as mutual condensation in the synthetic put procedure of the nitriles such as ammonification alkaline hydrolysis; And in actual production process, there are various labile factors, to the control of working condition, catastrophic failure etc., will inevitably condensation generate hydroxyl acids, peptide class, amides impurity and coloring matter such as raw material quality, workman.Because polymerization very easily occurs in the carbon nitrogen triple bond in the cyanogen root, particularly in ammonification and alkaline hydrolysis process, have more brown or black pyropolymer and generate, the glycine crystal that the later stage is wished to get white need to decolour with gac; In addition, in actual production process, reaction mass can have to a certain degree corrosion to production unit, thereby cause containing in the material certain metal ion, and the iminodiethanoic acid in the impurity, nitrilotriacetic acid(NTA) all are good complexing agents, so metal ion all exists with the metal complex form and is difficult to and separates in the feed liquid.Because in the production process, the glycin mother liquid recycled goes to deimpurity workshop section to only have decolouring, and under the processing condition of former alkaline hydrolysis and decolouring, peptide class, amides and metal complex all are difficult to be removed, thereby cause the constantly enrichment in system of above impurity.When recycled after for some time, in the production reaction system, particularly glycin mother liquid viscosity increases, glycine crystallization and separation difficulty, even cause producing and can not normally carry out.Therefore, part extraction or regularly to process glycin mother liquid be to guarantee that mother liquor impurity is in lower aq guarantees to produce and normally carries out and the key of production serialization.
Because carboxyl, amino all are very easily to react and the active function groups of condensation, therefore in ammonification heat-processed very easily mutually condensation generate acid amides, peptide, if alkaline hydrolysis not thoroughly, long-time high temperature concentrates or recycled repeatedly, will form following impurity:
H
2NCH
2CONHCH
2COOH
HOCH
2CONHCH
2COOH
H
2NCH
2CONHCH
2CONHCH
2COOH
HOCH
2CONHCH
2CONHCH
2CONHCH
2COOH
HOCH
2CONH
2
H
2NCH
2CONH
2
NH(CH
2COOH)CH
2CONHCH
2COOH
NH(CH
2CONHCH
2COOH)
2
NH
2CH
2CONH(CH
2COOH)
2
For above situation, the English power company technique personnel of Qing Hua Ziguang find through research, after alkaline hydrolysis is finished, the synthetic liquid of alkaline hydrolysis is refluxed separately, the sodium salt that has obtained glycine of highly selective, and the synthetic liquid of glycin mother liquid and liquid caustic soda mixed again alkaline hydrolysis, carry out the intermittence of high temperature reflux or the production of serialization, with acid amides, the impurity conversion such as peptide are glycine and by product iminodiethanoic acid etc., successful is converted into sodium sulfate byproduct with impurity ammonium sulfate, and effectively precipitation has been removed the wherein foreign pigment such as pyropolymer and metal, thereby increased the number of times that Recycling Mother Solution is applied mechanically.Technique of the present invention has been carried out the experiment of industrialization in production, and achieves success, glycin mother liquid after treatment, and from nuclear magnetic spectrum, other impurity peaks basically eliminate, only remaining glycine, iminodiethanoic acid and oxyacetic acid; The result who follows the tracks of with chemical analysis shows that alpha-acid can increase about 30%, and the content of IDA can increase about 40%, and peptide class, ester class in mother liquor almost 100% are converted into α-H and IDA, and nitrilotriacetic acid has 80% to be converted into IDA and oxyacetic acid approximately; Mother liquor condensing crystal last handling process is just like virgin material, reduced viscosity, and the salt particle diameter increases, and the gross profit that can bring is about 3500 yuan of every sides.This method improves the reaction solution quality by the content of impurity can be fallen floor level from source prevention and the mode for the treatment of later, well solves the reduction cost, reduce the material consumption energy consumption, real cleaner production, three wastes resource utilization, yield and the quality of raising product of realizing.
Summary of the invention
The purpose of this invention is to provide in a kind of preparing glycine by hydroxy acetonitrile method technique organic impurity and the inorganic impurity ammonium sulfate such as the acid amides removed in glycine reactant liquid and the mother liquor, peptide, precipitate wherein foreign pigment, reclaim glycine product and by-product iminodiethanoic acid and sodium sulfate in the glycin mother liquid, remove the method for coloring matter.
Specifically, the invention provides the method for removing the impurity in glycine reactant liquid and the mother liquor in a kind of preparing glycine by hydroxy acetonitrile method technique, it is after alkaline hydrolysis is finished, the synthetic liquid of alkaline hydrolysis is refluxed separately, the sodium salt that has obtained glycine of highly selective, perhaps the synthetic liquid of glycin mother liquid and liquid caustic soda is mixed again alkaline hydrolysis, carry out the intermittence of high temperature reflux or the production of serialization, with acid amides, the impurity conversion such as peptide are glycine and by product iminodiethanoic acid etc., and successfully impurity ammonium sulfate is converted into sodium sulfate byproduct simultaneously, and effectively precipitation has been removed the wherein foreign pigment such as pyropolymer and metal, thereby increased the number of times that Recycling Mother Solution is applied mechanically.The inventive method comprises the steps:
1) be 1%-30% with total alkalinity, the glycine that is preferably 5%-15% contains the alkali mixed solution and carries out the temperature rising reflux hydrolysis reaction, and temperature of reaction is preferably 90～120 ℃ at 60～150 ℃, and the reaction times is 1～10 hour, is preferably 2～8 hours;
2) until step 1) after hydrolysis reaction is complete, will reacts feed liquid and filter, obtain the alkaline hydrolysis hydrolyzed solution after removing black coking throw out wherein;
3) with step 2) the alkaline hydrolysis hydrolyzed solution that obtains sends the synthetic former reaction process of glycine back to, carry out acidifying, decolouring, concentrated desalination and separation, glycine crude product Crystallization Separation, obtain glycine crude product and glycin mother liquid, the glycine crude product refining obtains the sterling glycine;
4) glycin mother liquid that step 3) obtains can be according to producing actual needs, carry out independent alkaline cleaning or and after alkali solution liquid mixes, make glycine and contain the alkali mixed solution, apply mechanically back step 1) processing.
Among the present invention, glycin mother liquid refers to first product glycine crystallization filtrate and the elaboration glycine crystallization filtrate in the glycine production process.
The synthetic liquid of alkaline hydrolysis refers to alkali solution liquid or the deamination liquid in the glycine building-up process.
Alpha-acid refers to that the α position of carboxyl is connected with amino acid, mainly refers to glycine and iminodiethanoic acid here.
Glycine contains the alkali mixed solution and adopts glycin mother liquid, the synthetic liquid of alkaline hydrolysis or both mixed solutions adding appropriate bases (also can not adding, fixed according to total alkalinity) to obtain.Add the alpha-acid of alkali number in the glycin mother liquid as benchmark, be 1: 1～5 by alpha-acid and sodium hydroxide mol ratio, preferred alpha-acid is 1: 1.5～3 addings with the mol ratio of sodium hydroxide.After adding alkali, reaction solution total alkalinity (in the NaOH percentage composition) is 1%～30%, be preferably add alkali after, reaction solution total alkalinity (in the NaOH percentage composition) is 5%～15%.
Therefore, the present invention program preferably adopts mineral alkali under hot conditions material to be carried out back hydrolysis, destroys peptide bond and amido linkage in the impurity, is product glycine and by product iminodiethanoic acid thereby make impurity conversion; Simultaneously, under high temperature, alkaline condition, with the NH in the ammonium sulfate
4 +Form with ammonia is driven system out of, is converted into by-product sodium sulfate; Under the high temperature strong alkaline condition, make at last wherein polymerization carbonizing matter and metal complex, form precipitation, from system, separate out.
The inventive method has following advantage:
One, after alkaline hydrolysis is finished, by the synthetic liquid of alkaline hydrolysis is carried out high temperature reflux, the sodium salt that obtains glycine that can highly selective, the generation of inhibition of impurities guarantees the quality of glycine reactant liquid, thereby reduces the difficulty of mother liquid disposal from the source.
Its two, after glycin mother liquid mixes alkaline hydrolysis with liquid caustic soda again, can be glycine and by product iminodiethanoic acid etc. with impurity conversion such as acid amides, peptides, improve the transformation efficiency of raw material and the yield of product.
Its three, can effectively precipitate and remove the wherein foreign pigment such as pyropolymer and metal, and impurity ammonium sulfate is converted into sodium sulfate byproduct, reduce the decolouring cost of back and better condensing crystal take out qualified product.
The method that foregoing invention provides a kind of glycin mother liquid to process.Be specially adapted to the field of amino nitrile hydrolysis Preparation of amino acid, solved a coloured difficult problem that is difficult to suppress and apply mechanically impurity enriched in the process, the yield of product is greatly improved, the method that proposes is simple, widely applicable, clean environment firendly has good environmental benefit and economic benefit.
Description of drawings
Accompanying drawing 1 is the front nuclear magnetic resonance map of mother liquid disposal.
Accompanying drawing 2 is nuclear magnetic resonance maps behind mother liquid disposal.
Embodiment
The present invention can be further described with indefiniteness embodiment hereinafter.
Embodiment 1 alkali solution liquid reflow treatment
The synthetic liquid of the alkaline hydrolysis of glycine (analyze wherein alpha-acid content is that 15.45%, IDA content is 2.35%, basicity is 11.5%) 300g is joined in the four-hole boiling flask of 500ml, and the beginning back flow reaction then heats up.The back flow reaction temperature is controlled at about 115 ℃, and return time is 8 hours, obtains the 286.5g phegma, analyzes wherein alpha-acid (take glycine) content and is 2.51% as 17.32%, IDA (take iminodiethanoic acid) content.Phegma is used the spectrophotometric determination transparence after diluting 10 times, and transparence is 76.56%, and the transparence that the alkali solution liquid before refluxing records under diluting 10 times equally is 51.87%.
Analyzing the data that obtain from the experiment front and back can find out, alkali solution liquid is through refluxing, not only increased about 6.59% before the reaction of alpha-acid (in glycine) mass ratio in the reaction solution, increased about 1.98% before the reaction of IDA (in iminodiethanoic acid) mass ratio, and the transparence of solution also is greatly improved, the declaratives coloring matter has obtained elimination in situation about refluxing, partial impurities has changed into glycine and IDA.
The direct alkaline hydrolysis of embodiment 2 glycin mother liquids is processed
Get glycin mother liquid, analyze wherein that alpha-acid content is that 22.59%, IDA content is 5.68%, detecting its visible light transparence through ultraviolet-visible pectrophotometer is 75.65%, and its proton nmr spectra spectrogram is seen accompanying drawing 1.
This glycin mother liquid 100g is joined in the 250ml four-hole boiling flask, according to OH in alpha-acid in the glycin mother liquid and the liquid caustic soda
-Mol ratio be to add altogether 75.3g of 32% liquid caustic soda at 1: 2, basicity is 13.1%, alpha-acid content is that 12.86%, IDA content is 3.24%, then temperature rising reflux reaction.The back flow reaction temperature is controlled at about 115 ℃, and return time is 8 hours.
Reflux after 8 hours, stopped reaction, suction filtration obtains black precipitate, and 1.82g weighs after the throw out oven dry.Obtain filtrate 168.5g, analyzing wherein, alpha-acid (take glycine) content is 18.09%, IDA (take iminodiethanoic acid) content is 3.87%, and detecting its visible light transparence through ultraviolet-visible pectrophotometer is 90.65%, and its proton nmr spectra spectrogram is seen accompanying drawing 2.
Analytical data can obviously be found out before and after the reaction, refluxes through alkaline hydrolysis, has increased approximately 35% before the reaction of alpha-acid in the glycin mother liquid (in glycine) mass ratio, has increased about 15% before the reaction of IDA (in iminodiethanoic acid) mass ratio; Because filter after the reaction and removed black precipitate, transmittance is before reaction after the reaction; And from the proton nmr spectra spectrogram shown in accompanying drawing 1, the accompanying drawing 2, on the spectrogram (accompanying drawing 1) more impurity peaks is arranged before the reaction, and in the reaction rear (accompanying drawing 2), except glycine, iminodiethanoic acid, oxyacetic acid, substantially do not have other materials.
Can significantly find out from above analytical data, through the alkaline hydrolysis back flow reaction, not only can effectively remove peptide class and amides in the glycin mother liquid, make it be converted into glycine and iminodiethanoic acid, simultaneously, can effectively remove pyropolymer and metal complex.
Get glycin mother liquid, analyze wherein that alpha-acid content is that 22.59%, IDA content is 5.68%, (NH
4)
2SO
4Be 2.6%.Get alkali solution liquid, analyzing wherein, alpha-acid content is that 15.87%, IDA content is 2.27%.
This glycin mother liquid 100g is joined in the 250ml four-hole boiling flask, add the 200g alkali solution liquid again in flask, alpha-acid content is that 18.14%, IDA content is 3.41% in the analysis mixed solution, (NH
4)
2SO
4Be 0.9%, total alkalinity is 8.72%, then temperature rising reflux reaction.The back flow reaction temperature is controlled at about 115 ℃, and return time is 6 hours.Obtain filtrate 291.8g reaction solution after the backflow, analyze wherein that alpha-acid (take glycine) content is 19.43%, IDA (take iminodiethanoic acid) content is 3.73%, and basic inspection does not measure (NH
4)
2SO
4Content.
Can obviously find out from reaction front and back analytical data, glycin mother liquid and alkali solution liquid are through refluxing, alpha-acid in the glycin mother liquid (in glycine) content has increased about 2.28g before reacting, IDA (in iminodiethanoic acid) content has increased about 0.65g before reacting.
Can significantly find out from above analytical data, through refluxing, not only can effectively remove peptide class and amides in the glycin mother liquid, make it be converted into glycine and iminodiethanoic acid, simultaneously, can also remove (NH
4)
2SO
4Thereby, the quality of raising reaction solution.
Claims (5)
1. remove the method for the impurity in glycine reactant liquid and the mother liquor in the preparing glycine by hydroxy acetonitrile method technique, it is after alkaline hydrolysis is finished, the synthetic liquid of alkaline hydrolysis is refluxed separately, perhaps the synthetic liquid of glycin mother liquid and liquid caustic soda is mixed again alkaline hydrolysis, carry out the intermittence of high temperature reflux or the production of serialization, go deimpurity method, the method comprises the steps:
1) be that the glycine of 1%-30% contains the alkali mixed solution and carries out the temperature rising reflux hydrolysis reaction with total alkalinity, temperature of reaction is at 60～150 ℃, and the reaction times is 1～10 hour; It is to adopt glycin mother liquid, the synthetic liquid of alkaline hydrolysis or both mixed solutions that described glycine contains the alkali mixed solution, fixed depending on total alkali content, adds alkali or does not add that alkali obtains;
2) until step 1) after hydrolysis reaction is complete, will reacts feed liquid and filter, obtain the alkaline hydrolysis hydrolyzed solution after removing black coking throw out wherein;
3) with step 2) the alkaline hydrolysis hydrolyzed solution that obtains sends the synthetic former reaction process of glycine back to, carry out acidifying, decolouring, concentrated desalination and separation, glycine crude product Crystallization Separation, obtain glycine crude product and glycin mother liquid, the glycine crude product refining obtains the sterling glycine.
2. according to claim 1 method, wherein,
1) be that the glycine of 5%-15% contains the alkali mixed solution and carries out the temperature rising reflux hydrolysis reaction with total alkalinity, temperature of reaction is at 90～120 ℃, and the reaction times is 2～8 hours; Described glycine contains the alkali mixed solution and is the synthetic liquid of glycin mother liquid, alkaline hydrolysis or both mixed solutions, and is fixed depending on total alkali content, adds alkali or do not add that alkali obtains;
2) until step 1) after hydrolysis reaction is complete, will reacts feed liquid and filter, obtain the alkaline hydrolysis hydrolyzed solution after removing black coking throw out wherein;
3) with step 2) the alkaline hydrolysis hydrolyzed solution that obtains sends the synthetic former reaction process of glycine back to, carry out acidifying, decolouring, concentrated desalination and separation, glycine crude product Crystallization Separation, obtain glycine crude product and glycin mother liquid, the glycine crude product refining obtains the sterling glycine.
3. according to claim 1 and 2 method, wherein, in step 3) carry out afterwards following steps 4): with step 3) glycin mother liquid that obtains carry out independent alkaline cleaning or and after alkali solution liquid mixes, make glycine and contain the alkali mixed solution, apply mechanically back step 1) processing.
4. method according to claim 3, wherein, when adopting described glycin mother liquid, add the alpha-acid of alkali number in the glycin mother liquid as benchmark, alpha-acid and sodium hydroxide mol ratio are 1: 1～5, and alpha-acid refers to that the α position of carboxyl is connected with amino acid and iminodiethanoic acid.
5. according to claim 4 method, wherein, the mol ratio of alpha-acid and sodium hydroxide is 1: 1.5～3.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4014928A (en) * | 1974-08-08 | 1977-03-29 | Showa Denko Kabushiki Kaisha | Process for purifying α-amino acids |
| CN1616413A (en) * | 2003-10-14 | 2005-05-18 | 北京清华紫光英力化工技术有限责任公司 | Method for preparing glycine |
| CN1962611A (en) * | 2005-11-11 | 2007-05-16 | 重庆三峡英力化工有限公司 | Process for preparing glycine using hydroxy-acetonitrile method |
| CN1990459A (en) * | 2005-12-31 | 2007-07-04 | 重庆三峡英力化工有限公司 | Process for preparing glycine by hydroxy acetonitrile method |
-
2008
- 2008-12-16 CN CN 200810239718 patent/CN101747218B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4014928A (en) * | 1974-08-08 | 1977-03-29 | Showa Denko Kabushiki Kaisha | Process for purifying α-amino acids |
| CN1616413A (en) * | 2003-10-14 | 2005-05-18 | 北京清华紫光英力化工技术有限责任公司 | Method for preparing glycine |
| CN1962611A (en) * | 2005-11-11 | 2007-05-16 | 重庆三峡英力化工有限公司 | Process for preparing glycine using hydroxy-acetonitrile method |
| CN1990459A (en) * | 2005-12-31 | 2007-07-04 | 重庆三峡英力化工有限公司 | Process for preparing glycine by hydroxy acetonitrile method |
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