Background technology
Glycine is the important source material of industry such as chemical industry, medicine, agricultural chemicals, has purposes widely.At present, have several different methods to produce glycine, wherein, the alpha-halogen acid system is domestic main industrialized preparing process, and it is to be raw material with Mono Chloro Acetic Acid, ammonia, reacts in solvent phase in the presence of catalyzer urotropine (vulkacit H).Adopt the alpha-halogen acid system, solvent phase can be a water, but this water method is produced the method for glycine many defectives are arranged, for example exist catalyzer not reclaim, consumption is big, catalytic efficiency is low, the intact raw material of unreacted can not reuse, and owing to reasons such as system alkalescence are strong and moisture, easily generates the hydrolyzate oxyacetic acid, cause waste, contaminate environment; Inorganic salt separation difficulty such as the ammonium chloride that produces in the reaction, post-processing difficulty is big, building-up reactions endpoint difficulty or the like.In addition, reported also in the document that solvent is the method for preparing glycine of pure phase, but it still exists the reaction times longer, and reacts bad control, and catalyst efficiency is lower, detect (see figure 1) through NMR, there are two kinds of by products of 5%-7% to generate, thus still there is the lower defective of yield, and difficult solvent recovery, defectives such as solvent consumption is big are not suitable for the big production of industry.
There is bibliographical information to adopt hydroxyacetonitrile, amide and carbon dioxide reaction to prepare the method for glycine in recent years successively.This method can roughly be divided into following three classes again:
1) method that adopts alkali lye to carry out aftertreatment is referring to for example JP-A-06-065168, JP-A-05-320106, JP-A-53-031616, US5225592A, JP-A-02-250854, WO92/06069, JP-A-53-028115, CN1107139A.These patent documentations disclose employing alkali lye and have carried out aftertreatment, and therefore especially sulfuric acid neutralization of many employing acid produces salts solutions such as a large amount of sodium sulfate, vitriolate of tartar in subsequent operations, product purity is low, inorganic salt are carried secretly seriously, be difficult to carry out the three wastes and handle, and finished color is darker;
2) method that adopts acid solution to carry out aftertreatment, for example JP-A-2-286651, JP-A-04-066559, JP-A-02-306946, JP-A-53-028116, US2384816A.When adopting mineral acid or organic acid derivatives to be hydrolyzed, the general basic metal aqueous solution such as sodium hydroxide or potassium hydroxide of adopting of neutralization neutralizes, exist product purity low equally, inorganic salt are carried secretly, the three wastes are handled difficult problem, and the product color that obtains is darker.
3) method that adopts the highly basic resin cation (R.C.) to carry out aftertreatment, for example JP-A-03-190851.The purity of this method reaction yield and glycine is undesirable.Aforesaid method adopts ammonia to react, need under the condition of High Temperature High Pressure, carry out, and severe reaction conditions, facility investment is big, and the separation problem of inorganic salt is effectively solved as yet.
Therefore, the industrial method that needs a kind of better production glycine of exploitation.
At the deficiencies in the prior art, the present inventor has carried out deep research, found that, the mixture that for example adopts hereinafter described hydroxyacetonitrile maybe can obtain hydroxyacetonitrile carries out ammonia and separates, use in the milk of lime cheap and easy to get afterwards and acid hydrolysis solution, and generate the method for calcium precipitation through neutralization, can well solve glycine and separate difficult problem with inorganic salt, thereby find the method for low cost, high yield, high purity acquisition glycine.Detect through NMR, the generation of its by product oxyacetic acid, iminodiethanoic acid and nitrilotriacetic acid(NTA) can be effectively controlled, and is more suitable for suitability for industrialized production, so finished the present invention.
Summary of the invention
The purpose of this invention is to provide a kind of preparation method with aminoacetonitriles or the direct acidolysis of interior uride mixture, the acquisition glycine that neutralizes.
Preferably, the invention provides a kind of mixture and ammoniac compounds that adopts hydroxyacetonitrile maybe can produce hydroxyacetonitrile is initial feed, through ammonification, and acidolysis, neutralization procedure, prepares the method for glycine to high purity at high yield.
Specifically, the invention provides a kind of method for preparing glycine, this method comprises the steps:
1) aminoacetonitriles is mixed with mineral acid, obtain containing the acid hydrolysis solution of glycine inorganic acid salt;
2) above-mentioned acid hydrolysis solution is neutralized with milk of lime, obtain neutralizer (mainly containing glycine and mineral acid calcium);
3) the aftertreatment neutralizer obtains glycine product.
The inventive method can adopt for example following specific embodiments:
1) aminoacetonitriles, mineral acid are mixed, the mol ratio of reaction mass is an aminoacetonitriles: mineral acid=1: 0.2-4.0 is preferably 1: 0.5-2.5, control reaction temperature is between 60-200 ℃, be preferably 80-160 ℃, reacted 1-8 hour, suction filtration obtains containing the acid hydrolysis solution of glycine inorganic acid salt;
2) acid hydrolysis solution that step 1) is obtained neutralizes with milk of lime, the consumption of milk of lime be in and the consumption of mineral acid, for example, the mol ratio that adopts during reaction is the glycine inorganic acid salt: milk of lime=1: 0.2-4.0 is preferably 1: 0.5-2.5 obtains neutralization filtrate; The filter residue water lotion can be applied mechanically.
3) pre-treatment step 2) neutralization filtrate that obtains, dehydration, crystallization, oven dry obtains white glycine solid.
In the aforesaid method, the aminoacetonitriles employing prepares aminating reaction liquid with the method that hydroxyacetonitrile maybe can produce the mixture ammonification of hydroxyacetonitrile, directly carries out the acidolysis step.
Therefore, mixture and ammoniac compounds that the inventive method preferably adopts hydroxyacetonitrile maybe can produce hydroxyacetonitrile are initial feed, through ammonification, and acidolysis, neutralization procedure prepares glycine, and described method comprises the steps:
1) mixture that hydroxyacetonitrile solution maybe can be produced hydroxyacetonitrile mixes with ammoniac compounds, obtains containing the aminating reaction liquid of aminoacetonitriles;
2) the aminating reaction liquid that step 1) is obtained mixes with mineral acid, obtains containing the acid hydrolysis solution of glycine inorganic acid salt;
3) above-mentioned acid hydrolysis solution is neutralized with milk of lime, obtain neutralizer;
4) post-processing step 3) neutralizer that obtains, obtain glycine.
When implementing above-mentioned preferred method, in step 1), hydroxyacetonitrile solution maybe can produce the mixture of hydroxyacetonitrile and the reaction control temperature of ammoniac compounds is not higher than 100 ℃, for example, 0-90 ℃, reacts 0.2-3 hour; The mol ratio that adopts during reaction is a hydroxyacetonitrile: ammoniac compounds=1: 0.5-12.0 is preferably 1: 0.8-8.5.
In step 2) in, the mol ratio that adopts during reaction is an aminoacetonitriles: mineral acid=1: 0.2-4.0 is preferably 1: 0.5-2.5, control reaction temperature for example under 80-160 ℃, was reacted 1-8 hour between 60-200 ℃.
In step 3), the mol ratio that adopts during reaction is the glycine inorganic acid salt: milk of lime=1: 0.2-4.0 is preferably 1: 0.5-2.5.
The preferred process of the present invention can adopt for example following specific embodiments:
1) at-10 ℃ under 100 ℃, for example under 0-90 ℃, the mixture and the ammoniac compounds that hydroxyacetonitrile solution maybe can be produced hydroxyacetonitrile mix, reacted 0.2-3 hour, the mol ratio of reaction mass is a hydroxyacetonitrile: ammoniac compounds=1: 0.8-8.5, preferred 1: 0.8-5.5 obtains containing the aminating reaction liquid of aminoacetonitriles;
2) above-mentioned aminating reaction liquid, mineral acid are mixed, the mol ratio of reaction mass is an aminoacetonitriles: mineral acid=1: 0.2-4 is preferably 1: 0.5-2.5, control reaction temperature is no more than 200 ℃, for example under 80-160 ℃, reacted 1-8 hour, obtain the glycine inorganic acid salt;
3) with step 2) acid hydrolysis solution that obtains neutralizes with milk of lime, the consumption of milk of lime be in and the consumption of mineral acid, for example, the mol ratio that adopts during reaction is the glycine inorganic acid salt: milk of lime=1: 0.2-4.0 is preferably 1: 0.5-2.5 obtains neutralization filtrate.
4) post-processing step 3) neutralization filtrate that obtains, dehydration, crystallization, oven dry obtains white glycine solid.
In the present invention, described hydroxyacetonitrile solution maybe can produce the mixture of hydroxyacetonitrile, and for example consequence person can be the mixture of mixture, ammonium cyanide and formaldehyde of mixed solution, alkaline-earth metal prussiate and the formaldehyde of prussic acid and formaldehyde, preferably hydroxyacetonitrile.The molar weight of the hydroxyacetonitrile that adopts in the reaction is when only adopting hydroxyacetonitrile, in the molar weight of hydroxyacetonitrile, when adopting mixture, in the molar weight of formaldehyde in the mixture.
In the present invention, described ammoniac compounds is meant that ammonia maybe can produce the compound of ammonia, for example can be ammonia, ammoniacal liquor, inorganic ammonium salts such as ammonium nitrate, bicarbonate of ammonia, volatile salt etc., preferably ammonia and volatile salt.The molar weight of the ammoniac compounds that adopts in the reaction is when only adopting ammonia, in the molar weight of ammonia, when employing can produce the compound of ammonia, can produce the molar equivalent of ammonia in the compound.
In the present invention, described milk of lime can be the hydrated mixture of calcium hydroxide, calcium hydroxide and calcium oxide or hydrated mixture or the hydrated mixture or the solid mixture of solid mixture, calcium hydroxide and calcium oxide and/or sodium sulfate, the preferably mixture of calcium hydroxide, calcium hydroxide and calcium oxide of solid mixture, calcium hydroxide and calcium oxide and/or lime carbonate.Adopt the molar weight of alkali in the reaction, when only adopting calcium hydroxide, in the molar weight of calcium hydroxide, when adopting mixture, in the molar equivalent of calcium ion in the mixture.
In the present invention, described mineral acid can be sulfuric acid, nitric acid, carbonic acid, phosphoric acid, Lewis acid etc.Preferably sulfuric acid, phosphoric acid.
Adopt above-mentioned reaction method effectively to control molecular balance, obtain glycine, oxyacetic acid, iminodiethanoic acid and nitrilotriacetic acid(NTA) as required by control reaction raw materials, reaction conditions.
The inventive method has following advantage:
One when adopting hydroxyacetonitrile class and Ammonia to be the method for starting raw material, can effectively reduce the generation of glycolylurea, is easier to the hydrolysis of product intermediate.
Its two, be in the method for starting raw material adopting hydroxyacetonitrile class and Ammonia, can both can guarantee that hydrolysis was thorough earlier with the step of aminating reaction liquid acidolysis, overcome hydrolysis and with the isolating difficulty of inorganic salt.
Its three, neutralization procedure uses more cheap alkali---milk of lime is raw material, both can effectively reduce production costs, and has solved inorganic salt and product again cleverly and has been difficult to isolating problem; Adopt milk of lime to regulate the filtrate that iso-electric point obtains simultaneously, condensing crystal promptly obtains high-quality glycine.
Its four, in the inventive method, gypsum has multiple use, the atom utilization of this technology can reach 100%, is real friendly process, not only can guarantee the quality of glycine, and it is low, pollution-free to have a cost.
Its five, adopt glycine product purity>99% of the inventive method preparation, calcium ion content<0.1%, and the comprehensive yield of the inventive method can reach more than 95%.In addition, the inventive method entire reaction condition is very easily controlled, and for example, detects confirmation through NMR, and the generation of its by product oxyacetic acid, iminodiethanoic acid and nitrilotriacetic acid(NTA) can be effectively controlled, thereby is more suitable for carrying out suitability for industrialized production.
Embodiment
The present invention can be further described with indefiniteness embodiment hereinafter.
The preparation of embodiment 1 glycine
At room temperature in reactor, add 400 grams, 50% hydroxyacetonitrile solution, feed 90 gram ammonias, react after 45 minutes, obtain aminating reaction liquid.The aminating reaction liquid and 377 grams, 98% sulphuric acid soln that obtain are mixed, reacted 4 hours, obtain acid hydrolysis solution.To wherein adding 281 gram calcium hydroxides, suction filtration behind the thorough mixing is collected and is obtained neutralizer, and filter residue washes with water, merging filtrate.With the neutralization filtrate pre-treatment that obtains, dewater, reduce to room temperature, separate out crystallization, suction filtration washes with water and crystallizes to that wash water is colourless, with the oven dry of the solid that obtains, obtains purity and be 99.5% glycine, the original position yield 95.8% of the relative hydroxyacetonitrile of product.
The preparation of embodiment 2 glycine
In reactor, add 100 gram prussic acid and 300 gram formaldehyde mixture at normal temperatures, feed 336 gram volatile salts, react after 40 minutes, obtain aminating reaction liquid.The aminating reaction liquid and the 588 gram sulphuric acid solns that obtain are mixed, reacted 5 hours, obtain acid hydrolysis solution.To wherein adding 444 gram calcium hydroxide/calcium oxide/sodium sulfate mixtures, suction filtration behind the thorough mixing is collected and is obtained neutralization filtrate, and filter residue washes twice with water, merging filtrate.With the neutralization filtrate pre-treatment that obtains, dewater, reduce to room temperature, separate out crystallization, suction filtration washes with water and crystallizes to that wash water is colourless, with the oven dry of the solid that obtains, obtains purity and be 99.2% glycine, and product is with respect to the converted in-situ rate 96.7% of hydroxyacetonitrile.
The preparation of embodiment 3 glycine
At room temperature in reactor, add 400 gram hydroxyacetonitriles, feed 237 gram ammoniacal liquor, react deamination after 30 minutes, obtain 546 gram aminating reaction liquid.The aminating reaction liquid and the 248 gram hydrochloric acid solns that obtain are mixed, reacted 4 hours, obtain acid hydrolysis solution.To wherein adding 493 gram calcium hydroxide mixtures, suction filtration behind the thorough mixing is collected and is obtained neutralization filtrate, and filter residue washes twice with water, merging filtrate.With the neutralization filtrate pre-treatment that obtains, dewater, reduce to room temperature, separate out crystallization, suction filtration washes with water and crystallizes to that wash water is colourless, with the oven dry of the solid that obtains, obtains purity and be 99.3% glycine, and product is with respect to the original position yield 95.5% of hydroxyacetonitrile.
The preparation of embodiment 4 glycine
At room temperature in reactor, add 350 gram hydroxyacetonitriles, add 2844 gram bicarbonate of ammonia, react deamination after 40 minutes, obtain 2563 gram aminating reaction liquid.The aminating reaction liquid and the 345 gram phosphoric acid solutions that obtain are mixed, reacted 6 hours, obtain acid hydrolysis solution.To wherein adding 2975 gram calcium hydroxide/calcium oxide mixtures, suction filtration behind the thorough mixing is collected and is obtained neutralization filtrate, and filter residue washes twice with water, merging filtrate.With the neutralization filtrate pre-treatment that obtains, dewater, reduce to room temperature, separate out crystallization, suction filtration washes with water and crystallizes to that wash water is colourless, with the oven dry of the solid that obtains, obtains purity and be 99.7% glycine, and product is with respect to the original position yield 97.1% of hydroxyacetonitrile.
The preparation of comparative example's 1 glycine
Feed ammonia and carbonic acid gas respectively in hydroxyacetonitrile solution, add water, the mol ratio of reaction raw materials is a hydroxyacetonitrile: ammonia: carbonic acid gas: water=1: 2: 2: 50, control reaction temperature is 165 ℃, 14 standard atmospheric pressures, after 3 hours, reaction mixture is 80 ℃ of decompressions down, reduce to room temperature, separate solid, solid washs in the mixed solution of water and methyl alcohol, filters, 110 ℃ of drying under reduced pressure, purity obtains 98.5% glycine.