A kind of environmental protection method applying membrane integrating technique coproduction amino acid and analogue thereofTechnical field
The invention belongs to the production of organic compound, the technical field of abstraction and purification, be specifically related to a kind of environmental protection method applying membrane integrating technique coproduction amino acid and analogue thereof.
Background technology
Amino acid is the common name of the class organic compound containing amino and carboxyl, is the basic composition unit of biological function macro-molecular protein, is the base substance forming Animal nutrition desired protein.Amino acid analogue herein, refers to the amino acid derivative containing carboxyl and/or amino, the by product particularly produced in amino acids production process, and it is the same with amino acid has specific iso-electric point.Because amino acid is that human body and animal are necessary, so be widely used in the production fields such as medicine, food, agricultural chemicals, fodder additives.At present, amino acid whose synthetic method comprises extraction method, chemical synthesis, microbe fermentation method and enzyme process etc., and in order to make the amino acid of production have the better market competitiveness, two key points are just reduce production cost and improve product purity.Below for the production of glycine, set forth some problems existed in amino acids production purge process.
Glycine has another name called Padil, is a kind of important fine chemistry industry synthetic intermediate, is mainly used in synthetic pesticide glyphosate.Along with the raising of people's living standard, food, pharmaceutical industries become the greatest requirements field using glycine gradually, and its market demand is very large, and within 2010, global demand amount will close to 1000kt.The preparation method of glycine comprises Shi Teleike (Strecker) method, Chloroacetic Aminolysis and biological fermentation etc.In these methods, produce and obtain while glycine, also can other amino acid of by-product or amino acid analogue, need to carry out separation and purification especially, the glycine product of certain purity could be obtained, in its purge process, face again the problems such as purification circuit design, energy consumption control, three waste discharge.
Concrete again for the technique of Chloroacetic Aminolysis synthesis glycine, this technique exists a lot of not enough, and one is that the byproducts such as ammonium chloride are difficult to be separated, and cause poor product quality, can not meet the demand of medicine and foodstuffs industry, if refining, production cost is higher; Two is cannot reclaim as the urotropine of catalyzer, causes very large resource waste; Three is long reaction times, not easily operate continuously.And this explained hereafter goes back by-product iminodiethanoic acid while obtaining glycine.Iminodiethanoic acid, as a kind of important fine-chemical intermediate, is widely used in the various fields such as agricultural chemicals, electroplating industry, dyestuff, water treatment, electronics, also has good economic worth.But the problem such as in this chloroactic acid method by-product iminodiethanoic acid, the production of iminodiethanoic acid exists that technical process is long, product purity is low, cost is high, " three wastes " serious.How can be separated efficiently and to obtain highly purified glycine and iminodiethanoic acid, to become the key point simultaneously solving foregoing problems.
In described amino acid whose preparation technology, usually obtain the amino acid of alkali metal salt, the ammonia soln hydrolysis as aminoacetonitriles obtains the alkali solution liquid containing glycinate.Traditional separation purification method, mostly adopts the aqueous solution of the amino acid whose an alkali metal salt of acid neutralization, reclaims amino acid more afterwards by crystallization method.As Chinese patent literature CN1962611 discloses a kind of technique of preparing glycine by hydroxy acetonitrile method, by hydroxyacetonitrile, ammoniacal liquor hybrid reaction, obtain the ammonia soln of aminoacetonitriles, directly mineral alkali is added in the ammonification liquid obtained, obtain the alkali solution liquid containing glycinate, neutralize by after alkali solution liquid deamination with mineral acid, decolour again, destainer obtains glycine and inorganic salt through concentrated fractional crystallization and recrystallization.The shortcoming of this method is: as in and glycine sodium salt process in, solubleness and the glycine of the inorganic salt such as such as sodium sulfate and sodium-chlor etc. of neutralization generation are closely similar, fully glycine is not reclaimed by first degree crystalline, and need to carry out Step crystallization by adjust ph repeatedly, or temperature is regulated to carry out Step crystallization.These operations are all very miscellaneous, not easily hold, and production efficiency is low, and industrial implementation is very difficult.The more important thing is, described method can not be separated simultaneously and reclaim the iminodicarboxylic acid as by product and the amino acid as product.
Chinese patent literature CN101792397 discloses a kind of method utilizing electrodialysis separation of glycine and iminodiacetic acid (salt) acid mixture, it utilizes electrodialysis appts, difference according to glycine and iminodiethanoic acid iso-electric point adjusts pH, wherein a kind of charged and not charged to make, thus obtain different products at the dense hydroecium of electrodialysis unit and freshwater room enrichment.Although the method achieves being separated of glycine and iminodiethanoic acid, but first need glycinate to be transformed into glycine, and the interference of other inorganic acid salts in mixture, can not be had, be difficult to be connected with the glycine synthetic process of front and continued, can not coproduction be realized.In addition, this technique still can not solve the problem of the three wastes in glycine synthesis, and energy consumption is comparatively large, and product quality also has much room for improvement.
Based on above-mentioned prior art, researchist of the present invention is devoted to exploitation green, eco-friendly, can the technique of continuous seepage and amino acid separation and analogue thereof.
Summary of the invention
In view of this, first the present invention provides a kind of method of continuous seepage and separation of glycine and iminodiethanoic acid, the method can directly be connected with the synthesis technique of glycine mutually, directly the mixing solutions of glycinate and iminodiethanoic acid disalt is processed, without the need to being acidified with acid, not by-product inorganic salt, environmental protection, with short production cycle, product yield and purity high.
For achieving the above object, technical scheme of the present invention is:
A method for continuous seepage and separation of glycine and iminodiethanoic acid, comprises the following steps:
A, the mixing solutions of glycinate and the iminodiethanoic acid disalt obtained will be produced by first time bipolar membrane electrodialysis process, must mixing solutions containing glycine and iminodiethanoic acid one salt;
B, the described mixing solutions containing glycine and iminodiethanoic acid one salt again by conventional electrodialysis process, the glycine that must separate and iminodiethanoic acid one salts solution;
C, described iminodiethanoic acid one salts solution, by the process of second time bipolar membrane electrodialysis, obtain iminodiethanoic acid.
In described steps A, near the iso-electric point of by bipolar membrane electrodialysis the pH of solution being down to glycine, be converted to glycine by glycinate, and now iminodiethanoic acid disalt only changes iminodiethanoic acid one salt into; In described step B, then by conventional electrodialysis, uncharged glycine and charged iminodiethanoic acid one salt are separated; In described step C, then near the iso-electric point of by bipolar membrane electrodialysis the pH of solution being down to iminodiethanoic acid, be converted to iminodiethanoic acid by iminodiethanoic acid one salt.Being continuously separated of this process implementation glycine and iminodiethanoic acid, whole process without the need to being acidified with acid, not by-product inorganic salt, environmental protection; Due to the linking that technique is good, with short production cycle, and by bipolar membrane electrodialysis and conventional electrodialysis enriched products solution respectively, this solution, through simple concentrated, can obtain high yield and highly purified product.
Described glycinate and Iminodiacetate specifically can be the sylvite, sodium salt, ammonium salt etc. of glycine and iminodiethanoic acid.
Particularly, as a kind of specific form of bipolar membrane electrodialysis device, its Mo Zu unit is salt/alkali two cell-type, comprises cathode compartment, cationic exchange membrane, alkali lye room, Bipolar Membrane, feed liquid room, anolyte compartment, tensimeter, under meter, pipeline and direct supply.Operationally, salts solution enters feed liquid room by feed pump, and under DC electric field effect, water decomposition is become H by Bipolar Membrane+and OH-, enter feed liquid room and alkali room respectively.Positively charged ion enters alkali room by cationic exchange membrane, the OH dissociateed with Bipolar Membrane-be combined into mineral alkali, the H that weak acid radical ion and Bipolar Membrane ionize out+be combined into weak acid, obtain product.
As a kind of specific form of conventional electrodialysis device, it comprises by negative electrode, cationic exchange membrane, anion-exchange membrane, cathode compartment, concentration compartments (reception liquid chamber), diluting compartment (feed chamber), anolyte compartment, tensimeter, under meter, pipeline and direct supply.Operationally, iminodiethanoic acid one sodium salt solution enters diluting compartment by feed pump, under the effect of applying direct current electric field, positively charged ion and negatively charged ion arrive concentration compartments respectively by Zeo-karb and anionite-exchange resin, thus make to only have glycine in diluting compartment, only have iminodiethanoic acid one sodium salt solution in concentration compartments.
Further, during described first time bipolar membrane electrodialysis process, make material liquid pH be reduced to 5-6 (preferred pH is reduced to 5.5-6), obtain glycine; During described second time bipolar membrane electrodialysis process, make material liquid pH be reduced to 1.5-2.5, obtain iminodiethanoic acid.
Further, the device that described bipolar membrane electrodialysis uses is the bipolar membrane electrodialysis equipment being equipped with independent storage tank, recycle pump, strainer and interchanger, that is: in the stock liquid of described bipolar membrane electrodialysis equipment, alkali lye and pole liquid pipeline, the basin, recycle pump, strainer and the interchanger that connect successively is provided with respectively.Arranging of this structure to be strengthened the function of bipolar membrane electrodialysis device and is extended, and makes compact construction, simple to operate, cost is low, process energy consumption is low, the rate of recovery is high.Particularly, described basin is beneficial to circulation and the storage of feed liquid, expands batch output; Described recycle pump promotes feed liquid conversion and cycle in pipeline; Described strainer can the impurity such as filtering particulate matter, extends the life-span of bipolar membrane electrodialysis device; Described interchanger can carry out heat exchange to bipolar membrane electrodialysis device timely, promotes that reaction is carried out towards the direction needed.And, interchanger and bipolar membrane electrodialysis equipment are independently parts, can not be built in the one-piece construction destroying Bipolar Membrane membrane stack the heat-exchanging component in bipolar membrane electrodialysis device as other, the setting of interchanger can not affect expansion continuous prodution and the composition optimizes of bipolar membrane electrodialysis equipment.
Further, described bipolar membrane electrodialysis equipment comprises Bipolar Membrane membrane stack; Described Bipolar Membrane membrane stack both sides are any one a pair anodic-cathodic formed that titanium is coated with in ruthenium iridium, titanium platinum plating, Graphite Electrodes and stainless steel electrode, and more preferably described Bipolar Membrane membrane stack both sides are that a pair titanium is coated with ruthenium iridium anodic-cathodic.Further, in described Bipolar Membrane membrane stack, Bipolar Membrane and cationic exchange membrane are alternately placed, and form feed liquid room and alkali lye room respectively.Herein, interchanger specifically connects with Bipolar Membrane membrane stack by pipeline, to realize heat exchange function.
Further, during described bipolar membrane electrodialysis process, actuating current density is 300-500A/m2, operational outfit under the current density of this scope, namely can reduce facility investment, again reduce operation energy consumption, and total cost of production is reduced; Working temperature 10-40 DEG C, in this temperature range inner membrance, group activity is high, is beneficial to the migration of ion in film, raises the efficiency.Further, during described conventional electrodialysis process, actuating current density is 50-350A/m2, working temperature 10-40 DEG C.
Further, before the mixing solutions of described glycinate and iminodiethanoic acid disalt carries out first time bipolar membrane electrodialysis process, first film decolouring is carried out.The decolouring of product is the very thorny technical barrier of engineering technological, the aqueous solution of the amino acid whose an alkali metal salt that the chemical reactive synthesis methods such as such as Strecker method obtain contains a large amount of foreign pigment, make the coarse amino acid obtained be light brown and even chocolate, do not reach amino acid whose color standard.In order to improve the amino acid whose quality of the finished product, need to carry out desolventing technology to this liquid, traditional decoloring method uses activated carbon decolorizing technique, but due to removal of impurities thorough, the color of product is still very dark, affect product quality, and causing a large amount of losses of effective constituent in product, complex process because of charcoal absorption, production cost is high, productive rate is low, and product quality is not high.The present invention first carries out decolouring removal of impurities process herein, protects bipolar membrane electrodialysis device and conventional electrodialysis device on the one hand, achieves perfect linking with previous process; Need not carry out desolventing technology again to the follow-up target compound solution obtained again on the other hand, simplify step, and the concentrated crystalline product quality obtained is also high.
Further, described film decolouring is the decolouring of pressure-driven membrane filtration, and the film adopted is organic membrane, ceramic membrane or metallic membrane; The pore diameter range of film is 2-100nm, working temperature 10-40 DEG C, and pressure is 0.05-1Mpa.
Further, the glycine solution obtained in the fresh water to described step B conventional electrodialysis carries out membrane concentration, makes glycine concentration bring up to 15%-20%, then by MVR evaporative crystallization, obtains glycine product.When membrane concentration is to concentration 15%-20%, then carry out MVR evaporative crystallization, can effectively avoid peritectoid phenomenon to produce.
Further, described membrane concentration is pressure-driven membrane concentration, and the film adopted is rolling nanofiltration membrane or reverse osmosis membrane; The pore diameter range of film is 0.1-10nm, working temperature 10-40 DEG C, and pressure is 0.5-3Mpa.
Further, the iminodiacetic acid (salt) acid solution obtained in the sour room to described step C bipolar membrane electrodialysis carries out MVR evaporative crystallization, obtains iminodiacetic acid (salt) acid product.
The method of continuous seepage of the present invention and separation of glycine and iminodiethanoic acid, the feed liquid of to be the glycinate that obtains with organic synthesis and iminodiethanoic acid disalt feed liquid be purifying to be separated, first decolour with pressure drive membrane, the rear feed liquid of decolouring re-uses bipolar membrane electrodialysis makes pH be reduced between 5-6, and now feed liquid is glycine and iminodiethanoic acid one salt mixture; And then by conventional electrodialysis, obtain glycine and iminodiethanoic acid one salt respectively; The glycine obtained, again by pressure-driven membrane concentration, makes content bring up to 15%-20%, separates out, obtain glycine product by MVR is concentrated; The Bipolar Membrane that re-uses iminodiethanoic acid one salt obtained reduces pH at 1.5-2.5, obtains iminodiethanoic acid, then obtains iminodiacetic acid (salt) acid product by MVR evaporation concentration.
The method of continuous seepage of the present invention and separation of glycine and iminodiethanoic acid has the following advantages:
(1) the present invention has abandoned and has carried out the method for decolouring with gac, avoids the absorption of gac to Sodium glycocollate and iminodiacetic acid sodium, improves the extraction yield of decolouring product.
(2) bipolar membrane electrodialysis process is used, can directly be connected mutually with the synthesis technique of front and continued glycine, do not need to add acidifying again to the feed liquid containing Sodium glycocollate and Iminodiacetic acid sodium salt that synthesis obtains, save the input of acid, the generation of no coupling product sodium sulfate, makes separating-purifying more simple simultaneously.
(3) Bipolar Membrane electrolysis generates mineral alkali (as sodium hydroxide) by product simultaneously and reclaims for chemosynthesis reaction again, not only reduces production cost, and decreases the aftertreatment technology of waste liquid.
(4) glycine obtained improves concentration by membrane concentration, reduces MVR energy consumption.
(5) Bipolar Membrane is homogeneous membrane, and membrane pore size is little, and resistance is low, and rate of permeation is high, and power consumption is little, and separating effect is high.
Thus, achieve and be connected with the direct of glycine synthetic process, achieve the circulation Sustainable Production of product, improve product yield and purity, shorten the production cycle, environmental protection, environmental friendliness.
In addition, compared with the present invention carries out amino acid whose separating technology with employing ion exchange method, also overcome the following inherent defect that ion exchange resin exists: the inventive method can not cause removing the reduction of ion efficiency along with the saturated of functional group on ion exchange resin, quality product is declined; Ion exchange resin is organic substance, can break, monomer outflow etc. and cause the stripping of organic substance because of oxygenolysis, mechanicalness; Exchange resin also disintegration fragment etc. can cause the increase of particle in feed liquid; The regenerative process operation of exchange resin comparatively bothers, and requires great effort consuming time, reduces production efficiency; And ion exchange resin regeneration process need consumes soda acid medicament, the acidic and alkaline waste water after regeneration also needs further process; The pH value of solution entering ion exchange unit should be not more than 12, and usually by chemical reaction obtain containing the pH value of water solution of amino acid an alkali metal salt up to 14, the acid-base solution of bipolar membrane electrodialysis ability 6%-10%, eliminates the operation of resulting solution reagent adding adjust ph again; The inventive method self production obtains sodium hydroxide and can be back to use on synthesis technique, saves the input of exogenously added alkali, it also avoid the generation as adopted by product-sodium sulfate in exchange resin technique.
Conceive identical with separation of glycine with the method for iminodiethanoic acid with above-mentioned continuous seepage, the present invention also provides a kind of continuous seepage and is separated the two or more method with the organic compound of different iso-electric point.Described organic compound is amino acid, or is the amino acid derivative containing carboxyl and/or amino, the by product particularly produced in amino acids production process.The method can directly be connected with amino acid whose synthesis technique mutually, directly processes, without the need to being acidified with acid the mixing solutions of the amino acid of different iso-electric point and the salt of analogue thereof, not by-product inorganic salt, environmental protection, with short production cycle, product yield and purity high.
For achieving the above object, technical scheme of the present invention is:
Continuous seepage be separated a two or more method with the organic compound of different iso-electric point, described organic compound is amino acid, or is the amino acid derivative containing carboxyl and/or amino, comprises the following steps:
The mixing solutions I of the salt produced containing two or more organic compound described in acquisition is passed through first time bipolar membrane electrodialysis process, must containing the mixing solutions II of the first organic compound with the salt of residue organic compound; Described mixing solutions II passes through first time conventional electrodialysis process, the salts solution of the first organic compound that must separate and residue organic compound; The salts solution of described residue organic compound, again through the process of second time bipolar membrane electrodialysis, must contain the solution of the second organic compound;
If described containing the salt also containing other organic compound in the solution of the second organic compound, then the step of conventional electrodialysis process is arrived in repetition conventional electrodialysis process, bipolar membrane electrodialysis process again, continues to be separated, obtains described organic compound respectively.
In above-mentioned steps, during described bipolar membrane electrodialysis process, near the iso-electric point of that organic compound obtained needed for the pH of feed liquid is down to, namely this organic compound is transformed into himself and charged hardly from its salt form, again by conventional electrodialysis process, this uncharged organic compound is separated from feed liquid.Repeat this process, namely achieve the separation of one and another organic compound.
Further, described in there is the organic compound of different iso-electric point, preferably their iso-electric point differences are between any two more than 2.
Further, described organic compound be in glycine, L-Ala, methionine(Met), Serine, α-amino-isovaleric acid, leucine, Isoleucine, Threonine, aminopropanol and iminodicarboxylic acid any two or more; Preferred glycine and iminodiethanoic acid.The salt of described organic compound is the sylvite, sodium salt, ammonium salt, vitriol, phosphoric acid salt, acetate etc. of organic compound; Particular certain cancers.
Further, the device that described bipolar membrane electrodialysis uses is the bipolar membrane electrodialysis equipment being equipped with independent storage tank, recycle pump, strainer and interchanger, that is: in the stock liquid of described bipolar membrane electrodialysis equipment, alkali lye and pole liquid pipeline, the basin, recycle pump, strainer and the interchanger that connect successively is provided with respectively.
Further, described bipolar membrane electrodialysis equipment comprises Bipolar Membrane membrane stack; Described Bipolar Membrane membrane stack both sides are any one a pair anodic-cathodic formed that titanium is coated with in ruthenium iridium, titanium platinum plating, Graphite Electrodes and stainless steel electrode, and more preferably described Bipolar Membrane membrane stack both sides are that a pair titanium is coated with ruthenium iridium anodic-cathodic.Further, in described Bipolar Membrane membrane stack, Bipolar Membrane and cationic exchange membrane are alternately placed, and form feed liquid room and alkali lye room respectively.
Further, the mixing solutions I of the salt of described organic compound, before carrying out first time bipolar membrane electrodialysis process, first carries out film decolouring; Be separated the solution of the single organic compound obtained after described bipolar membrane electrodialysis or conventional electrodialysis process, evaporate to obtain product by membrane concentration, MVR successively respectively, or directly evaporate to obtain product by MVR.
Aforementioned continuous seepage and separation of glycine and the method for iminodiethanoic acid are a kind of embody rule of " continuous seepage be separated the two or more method with the organic compound of different iso-electric point " herein, it has the identical advantage of preceding method, can realize two or more there is being continuously separated of the organic compound of different iso-electric point, and be convenient to be connected mutually with the technique of these organic compound, without the need to being acidified with acid, not by-product inorganic salt, achieve the circulation Sustainable Production of product, improve product yield and purity, shorten the production cycle, environmental protection, environmental friendliness.
Accompanying drawing explanation
Fig. 1 is the process flow sheet of continuous seepage of the present invention and separation of glycine and iminodiethanoic acid;
Fig. 2 is the fundamental diagram of bipolar membrane electrodialysis device;
Fig. 3 is a kind of structural representation of bipolar membrane electrodialysis device in the present invention;
Fig. 4 is the fundamental diagram of conventional electrodialysis device;
Fig. 5 is the pH of sour room and the graph of a relation of time in bipolar membrane electrodialysis process;
Fig. 6 is the time dependent graph of a relation of diluting compartment specific conductivity in conventional electrodialysis process;
Fig. 7 is specific conductivity time dependent graph of a relation in concentration compartments's in conventional electrodialysis process;
Fig. 8 is pH time dependent graph of a relation in concentration compartments in conventional electrodialysis process;
Fig. 9 is continuous seepage of the present invention and be separated the two or more process flow sheet with the organic compound of different iso-electric point.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in detail.Fig. 1 is the process flow sheet of continuous seepage of the present invention and separation of glycine and iminodiethanoic acid.The feed liquid of this flow process to be the Sodium glycocollate that obtains with organic synthesis and Iminodiacetic acid sodium salt feed liquid be purifying to be separated, it first decolours with pressure drive membrane, the rear feed liquid of decolouring re-uses Bipolar Membrane method makes pH be reduced between 5-6, now feed liquid is glycine and iminodiethanoic acid one sodium salt mixt, and then by electrodialysis unit, obtain glycine and iminodiethanoic acid one sodium salt respectively.The glycine obtained, again by pressure-driven membrane concentration, makes content bring up to 20-30%, separates out, obtain glycine product by MVR is concentrated; The Bipolar Membrane that re-uses iminodiethanoic acid one sodium salt obtained reduces pH at 1.5-2.5, obtains iminodiethanoic acid, then obtains iminodiacetic acid (salt) acid product by MVR evaporation concentration.
Fig. 2 is the fundamental diagram of bipolar membrane electrodialysis device.Its Mo Zu unit is salt/alkali two cell-type, comprises cathode compartment, cationic exchange membrane, alkali lye room, Bipolar Membrane, feed liquid room, anolyte compartment, tensimeter, under meter, pipeline and direct supply.Described Bipolar Membrane membrane stack both sides are any one a pair anodic-cathodic formed that titanium is coated with in ruthenium iridium, titanium platinum plating, Graphite Electrodes and stainless steel electrode, and internal bipolar film and cationic exchange membrane are alternately placed, and form feed liquid room and alkali lye room respectively.Operationally, salts solution enters feed liquid room by feed pump, and under DC electric field effect, water decomposition is become H by Bipolar Membrane+and OH-, enter feed liquid room and alkali room respectively.Positively charged ion enters alkali room by cationic exchange membrane, the OH dissociateed with Bipolar Membrane-be combined into sodium hydroxide, the H that weak acid radical ion and Bipolar Membrane ionize out+be combined into weak acid, obtain product.
Fig. 3 is a kind of structural representation of bipolar membrane electrodialysis device in the present invention.This bipolar membrane electrodialysis device comprises Bipolar Membrane membrane stack 8; And be connected with pole liquid pipeline with the stock liquid of bipolar membrane electrodialysis device, alkali lye, be provided with the basin, recycle pump, strainer and the interchanger that connect successively respectively; Described interchanger is connected with Bipolar Membrane membrane stack 8 respectively by pipeline.Particularly, be connected with stock liquid pipeline, be provided with the head tank 41, feed liquid recycle pump 51, feed liquid cartridge filter 61 and the feed liquid interchanger 71 that connect successively; Be connected with alkali lye pipeline, be provided with the alkali liquid tank 42, NaOH solution circulating pump 52, alkali lye cartridge filter 62 and the alkali lye interchanger 72 that connect successively; Be connected with pole liquid pipeline, be provided with the pole flow container 43, pole liquid recycle pump 53, pole liquid cartridge filter 63 and the pole liquid interchanger 73 that connect successively; Between the described neighboring devices be connected with pipeline, by pipeline, the upper outlet of a device is connected with the import of next device.In addition, also depict rectifier 9 in figure, the positive and negative electrode of rectifier connects with Bipolar Membrane membrane stack respectively by wire (D1, D2).
Fig. 4 is the fundamental diagram of conventional electrodialysis device.It comprises by negative electrode, cationic exchange membrane, anion-exchange membrane, cathode compartment, concentration compartments (reception liquid chamber), diluting compartment (feed chamber), anolyte compartment, tensimeter, under meter, pipeline and direct supply.Operationally, iminodiethanoic acid one sodium salt solution enters diluting compartment by feed pump, under the effect of applying direct current electric field, positively charged ion and negatively charged ion arrive concentration compartments respectively by Zeo-karb and anionite-exchange resin, thus make to only have glycine in diluting compartment, only have iminodiethanoic acid one sodium salt solution in concentration compartments.
Fig. 5 is the pH of sour room and the graph of a relation of time in bipolar membrane electrodialysis process.During operation, when reaching near the amino acid whose iso-electric point that will change to pH, namely obtain this almost uncharged amino acid.
Fig. 6-8 is diluting compartment specific conductivity and concentration compartments time dependent graph of a relation respectively in conventional electrodialysis process, the time dependent graph of a relation of concentration compartments pH.Electrodialytic progress can be judged by the change of specific conductivity and pH.
Fig. 9 is continuous seepage of the present invention and be separated the two or more process flow sheet with the organic compound of different iso-electric point.This flow process is by the mixing solutions I of the salt containing two or more organic compound by first time bipolar membrane electrodialysis process, must containing the mixing solutions II of the first organic compound with the salt of residue organic compound; Described mixing solutions II passes through first time conventional electrodialysis process, the salts solution of the first organic compound that must separate and residue organic compound; The salts solution of described residue organic compound, must containing the mixing solutions III of the second organic compound with the salt of residue organic compound again through the process of second time bipolar membrane electrodialysis; Described mixing solutions III passes through the traditional electrodialysis process of second time, the salts solution of the second organic compound that must separate and residue organic compound; If the salt also containing other organic compound in the salts solution of residue organic compound, then repeat the step of bipolar membrane electrodialysis process and conventional electrodialysis process, continue to be separated, obtain described organic compound respectively.The solution being separated the organic compound obtained evaporates to obtain product by membrane concentration, MVR, or directly evaporates to obtain product by MVR.
Referring to the technical process of Fig. 1, the preferred embodiments of the present invention are described in detail.In preferred embodiment, as shown in Figure 2, the principle of the conventional electrodialysis device of employing as shown in Figure 4 for the principle of the bipolar membrane electrodialysis device of employing.The experimental technique of following unreceipted actual conditions, conveniently condition is carried out.
Below get production that synthesis feed liquid that preparing glycine by hydroxy acetonitrile method technique obtains carries out glycine and iminodiethanoic acid and be separated (concrete method prepare reference patent application CN1962611A of synthesis feed liquid is carried out), the main component that this synthesis feed liquid initially contains is Sodium glycocollate and iminodiacetic acid sodium.
Embodiment 1
Operation steps:
(1) film decolouring: synthetic material liquid pump is entered pressure drive membrane decolouring unit, institute adopts film decolouring unit be followed successively by ultrafiltration system, nanofiltration system, ultrafiltration system employing membrane pore size be about 200nm, crossflow velocity 3cm/s, working pressure is 0.15Mpa; Nanofiltration system adopts membrane pore size to be about 5nm, crossflow velocity 3.2cm/s, and working pressure is 0.9Mpa, operating temperature about 25 DEG C.While film decolouring, also removes produce in glycine building-up process pigment, macromolecule the impurity such as by product.
(2) first time bipolar membrane electrodialysis: the feed liquid after decolouring does not need adding medicine adjust ph, directly passes into the feed liquid room of bipolar membrane electrodialysis.As shown in Figure 2, alkali lye room passes into the NaOH of 0.1mol/L as receiving liquid, and pole liquid is the Na of 0.5mol/L2sO4solution.Feed liquid flow 42L/h, crossflow velocity 3cm/s, feed liquid circulates, until reaching pH is between 5.5-6.After pH reaches, feed liquid room obtains glycine and iminodiethanoic acid one sodium solution, then proceeds to next step technique continuation separation; Alkali lye room obtains sodium hydroxide solution, and concentration is 5%, then the synthesis technique proceeding to glycine continues to use.In bipolar membrane electrodialysis process, the pH of feed liquid room (sour room) and the relation of time are as shown in Figure 5.
The Bipolar Membrane film of the bipolar membrane electrodialysis device of above-mentioned use is to being of a size of 100 × 200mm, membrane stack both sides are respectively a pair titanium and are coated with ruthenium iridium anodic-cathodic, internal bipolar film and cationic exchange membrane are alternately placed, and form feed liquid room and alkali lye room, totally 10 repeating units respectively.Bipolar membrane electrodialysis actuating current density is 350 A/m2, working temperature is 25 DEG C.By the rectifier steady process current density be connected with Bipolar Membrane membrane stack, head tank recycle pump, alkali liquid tank recycle pump and pole flow container recycle pump maintain respectively feed liquid room, alkali lye room and pole liquid chamber flow at 30L/h, after running 55min, the pH of feed liquid room drops to about 5.9 from about 11.
(3) conventional electrodialysis: the diluting compartment of conventional electrodialysis device passes into glycine and iminodiethanoic acid one sodium solution, as shown in Figure 4, concentration compartments passes into iminodiethanoic acid one sodium solution of 0.1%, and pole liquid is the Na of 0.3mol/L2sO4solution.Feed liquid flow 56L/h, crossflow velocity 4cm/s, feed liquid circulates, until the content reaching iminodiethanoic acid one sodium in diluting compartment is within 0.8%, then proceeds to next step technique and uses.Conventional electrodialysis actuating current density is 100A/m2, work Wen Weidu 30 DEG C.In conventional electrodialysis process, as shown in Figure 6, as shown in Figure 7, the pH of concentration compartments and timing relationship are as shown in Figure 8 for the specific conductivity of concentration compartments and timing relationship for the specific conductivity of diluting compartment and timing relationship.
(4) glycine concentrates: the glycine solution concentration that conventional electrodialysis device desalination formula obtains is about 9-12%, iminodiethanoic acid one na concn is about 1-1.5%, if directly evaporation concentration, energy consumption is higher, so adopt two-pass reverse osmosis membrane concentration method, first step reverse osmosis membrane is concentrated makes glycine concentration be concentrated to about 20%, permeate glycine concentration is 0.6%, concentrate through second stage reverse osmosis membrane again, glycine after concentrated continues to get back in technique and uses, and the product water of second stage reverse osmosis membrane is also got back in technique and used.MVR vaporization operation step is: first the glycine feed liquid of about 20% passes through preheater, stablize and enter vaporizer, stop fresh feed pump, ON cycle pump makes Matter Transfer, opens raw steam stop, steam is introduced vaporizer shell side, start to heat up to material in system, rear unlatching vapour compressor, when system reaches vaporization temperature, cuts out raw steam stop.Acquisition glycine product is white powder, and purity is 93.89%, and yield is 94.25%.
(5) second time bipolar membrane electrodialysis: iminodiethanoic acid one sodium solution that conventional electrodialysis device concentration compartments obtains, does not need adding medicine adjust ph, directly pass into bipolar membrane electrodialysis device, pH is reduced between 1.5-2.5.After pH reaches, obtain iminodiacetic acid (salt) acid solution in the feed liquid room (sour room) of bipolar membrane electrodialysis device; Obtain sodium hydroxide solution in alkali lye room, concentration is 4%, then the synthesis technique proceeding to glycine continues to use.The optimum configurations of bipolar membrane electrodialysis operation is: alkali lye room passes into the NaOH of 0.1mol/L as receiving liquid, and pole liquid is the Na of 0.5mol/L2sO4solution, feed liquid flow 49L/h, crossflow velocity 3.5cm/s, feed liquid circulates, until reaching pH is between 1.5-2.5.
(6) iminodiacetic acid (salt) acid crystal: the iminodiacetic acid (salt) acid solution that the feed liquid room of bipolar membrane electrodialysis device obtains is about 5-8%, directly enters MVR vapo(u)rization system condensing crystal, evaporates the water obtained and uses in production as process water.Obtaining iminodiacetic acid (salt) acid product is white powder, and purity is 90.56%, and yield is 91%.After above-mentioned production one-period, compared to the technique adopting traditional crystallization separation system, the feed concentration that this joint process enters vapo(u)rization system improves, and reduces evaporated water, reduces energy consumption; Compared to the technique adopting ionic energy transfer system, this joint process avoid exchange resin regenerative process complicated operation, require great effort consuming time, consume soda acid medicament, produce the shortcomings such as waste water, avoid the generation of exchange resin sodium sulfate byproduct, self production simultaneously obtains sodium hydroxide and is back to use on synthesis technique, eliminates the cost investment of exogenously added alkali on synthesis technique.
Embodiment 2
Operation steps:
(2) film decolouring: synthetic material liquid pump is entered pressure drive membrane decolouring unit, institute adopts film decolouring unit be followed successively by ultrafiltration system, nanofiltration system, ultrafiltration system employing membrane pore size be about 150nm, crossflow velocity 3.5cm/s, working pressure is 0.2Mpa; Nanofiltration system adopts membrane pore size to be about 4nm, crossflow velocity 3.5cm/s, and working pressure is 1Mpa, operating temperature about 25 DEG C.While film decolouring, also removes produce in glycine building-up process pigment, macromolecule the impurity such as by product, due to pressure increase, decolorizing effect does not have embodiment 1 desirable.
(2) first time bipolar membrane electrodialysis: the feed liquid after decolouring does not need adding medicine adjust ph, directly passes into the feed liquid room of bipolar membrane electrodialysis.Alkali lye room passes into pure water as receiving liquid, and pole liquid is the Na of 0.2mol/L2sO4solution.Feed liquid flow 112L/h, crossflow velocity 4cm/s, feed liquid circulates, until reaching pH is between 5.5-6.After pH reaches, feed liquid room obtains glycine and iminodiethanoic acid one sodium solution, then proceeds to next step technique continuation separation; Alkali lye room obtains sodium hydroxide solution, and concentration is 4%, then the synthesis technique proceeding to glycine continues to use.What adopt due to initial alkali lye is pure water, makes initial current lower, and the operating time increases.
The Bipolar Membrane film of the bipolar membrane electrodialysis device of above-mentioned use is to being of a size of 200 × 400mm, membrane stack both sides are respectively a pair titanium and are coated with ruthenium iridium anodic-cathodic, internal bipolar film and cationic exchange membrane are alternately placed, and form feed liquid room and alkali lye room, totally 10 repeating units respectively.Bipolar membrane electrodialysis actuating current density is 300 A/m2, working temperature is 25 DEG C.By the rectifier steady process current density be connected with Bipolar Membrane membrane stack, head tank recycle pump, alkali liquid tank recycle pump and pole flow container recycle pump maintain feed liquid room, alkali lye room and pole liquid chamber certain flow respectively, and the pH of feed liquid room drops to about 5.5-6 from about 11.
(3) conventional electrodialysis: the diluting compartment of conventional electrodialysis device passes into glycine and iminodiethanoic acid one sodium solution, and concentration compartments passes into pure water solution, and pole liquid is the Na of 0.5mol/L2sO4solution.Feed liquid flow 84L/h, crossflow velocity 3cm/s, feed liquid circulates, until the content reaching iminodiethanoic acid one sodium in diluting compartment is within 1%, then proceeds to next step technique and uses.Conventional electrodialysis actuating current density is 80A/m2, work Wen Weidu 30 DEG C.
(4) glycine concentrates: the glycine solution concentration that conventional electrodialysis device desalination formula obtains is about 8-10%, iminodiethanoic acid one na concn is about 1.5-2%, if directly evaporation concentration, energy consumption is higher, so adopt two-pass reverse osmosis membrane concentration method, first step reverse osmosis membrane is concentrated makes glycine concentration be concentrated to about 18%, permeate glycine concentration is 0.4%, concentrate through second stage reverse osmosis membrane again, glycine after concentrated continues to get back in technique and uses, and the product water of second stage reverse osmosis membrane is also got back in technique and used.MVR vaporization operation step is: first glycine feed liquid passes through preheater, stablize and enter vaporizer, stop fresh feed pump, ON cycle pump makes Matter Transfer, opens raw steam stop, steam is introduced vaporizer shell side, start to heat up to material in system, rear unlatching vapour compressor, when system reaches vaporization temperature, cuts out raw steam stop.Obtaining glycine product is white powder, and purity is 91.23%, and yield is 92.05%.
(6) second time bipolar membrane electrodialysis: iminodiethanoic acid one sodium solution that conventional electrodialysis device concentration compartments obtains, does not need adding medicine adjust ph, directly pass into bipolar membrane electrodialysis device, pH is reduced between 1.5-2.5.After pH reaches, obtain iminodiacetic acid (salt) acid solution in the feed liquid room (sour room) of bipolar membrane electrodialysis device; Obtain sodium hydroxide solution in alkali lye room, concentration is 4%, then the synthesis technique proceeding to glycine continues to use.The optimum configurations of bipolar membrane electrodialysis operation is: alkali lye room passes into pure water as receiving liquid, and pole liquid is the Na of 0.3mol/L2sO4solution, feed liquid flow 112L/h, crossflow velocity 4cm/s, feed liquid circulates, until reaching pH is between 1.5-2.5.
(6) iminodiacetic acid (salt) acid crystal: the iminodiacetic acid (salt) acid solution that the feed liquid room of bipolar membrane electrodialysis device obtains is about 8%, directly enters MVR vapo(u)rization system condensing crystal, evaporates the water obtained and uses in production as process water.Obtaining iminodiacetic acid (salt) acid product is white powder, and purity is 89.12%, and yield is 90.08%.
Comparative example 1
Get hydroxyacetonitrile and excess of ammonia water and be obtained by reacting ammonification liquid containing aminoacetonitriles, add sodium hydroxide again, be obtained by reacting sodium glycinate solution, after vulcanization acid neutralization, the mol ratio adopted during reaction is Sodium glycocollate: mineral acid=1:1.5, obtains glycine and sodium sulfate mixture; The difference in solubility of recycling glycine and sodium sulfate, by fractional crystallization and recrystallization, obtains glycine and sodium sulfate respectively.The product that this technique obtains exists for close to pure glycine solution, achieves being separated of glycine and iminodiacetic acid sodium salt.But, in this technique and in Sodium glycocollate process, the solubleness and the glycine that produce sodium sulfate inorganic salt are closely similar, fully do not reclaim glycine by first degree crystalline, and need to carry out Step crystallization by adjust ph repeatedly, or temperature is regulated to carry out Step crystallization.These operations are all very miscellaneous, not easily hold, and production efficiency is low, and industrial implementation is very difficult.
Comparative example 2
Get hydroxyacetonitrile and excess of ammonia water and be obtained by reacting ammonification liquid containing aminoacetonitriles, add sodium hydroxide again, be obtained by reacting Sodium glycocollate and iminodiacetic acid sodium solution, after vulcanization acid neutralization, pH value of solution is made to drop near 5.9, now solution is mainly glycine, iminodiacetic acid sodium and sodium sulfate, and then enter electrodialysis unit, open the pH value of the on-line automatic regulator solution of pH, regulation range is between 5.8-6.1, hydrochloric acid and sodium hydroxide solution is used to regulate, finally obtain the mixing solutions that dense room is iminodiacetic acid sodium and sodium sulfate, dense room adds sulfuric acid neutralization again, pH value of solution is made to drop near 2, now solution is mainly iminodiethanoic acid and sodium sulfate, and then enter electrodialysis unit, iminodiethanoic acid is separated with sodium sulfate.But this technique produces sodium sulfate, adds the investment of electrodialysis unit, and also have that product purity is low, crystallization time inorganic salt sodium sulfate is carried secretly, three-protection design is difficult, the problem that product color waits more deeply.
Comparative example 3
Get production that synthesis feed liquid that preparing glycine by hydroxy acetonitrile method technique obtains carries out glycine and iminodiethanoic acid and be separated (concrete method prepare reference patent application CN1962611A of synthesis feed liquid is carried out), the main component that this synthesis feed liquid initially contains is Sodium glycocollate and iminodiacetic acid sodium.
The synthesis liquid that obtains (main component be Sodium glycocollate, iminodiacetic acid sodium mixed solution, regenerator and soft water) enters continuous ion exchange unit simultaneously, continuous switch runs without interruption for 24 hours, from obtaining glycine solution from friendship device discharge port continuously, byproduct discharge is collected and is obtained sodium sulfate byproduct, reclaim(ed) sulfuric acid sodium.Adopt ion exchange resin to prepare the method for glycine, the purity of this method reaction yield and glycine is all undesirable, severe reaction conditions, and facility investment is large, and the separation problem of inorganic salt is also effectively solved, regeneration issues loss chemical agent.
What finally illustrate is, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although with reference to preferred embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that, can modify to technical scheme of the present invention or equivalent replacement, and not departing from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.