CN101591253A

CN101591253A - The novel process for acidifying of glycin and other carboxylates

Info

Publication number: CN101591253A
Application number: CNA2008102113988A
Authority: CN
Inventors: 罗伟; 尹应武
Original assignee: TH-UNIS INSIGHT Co Ltd
Current assignee: TH-UNIS INSIGHT Co Ltd
Priority date: 2008-05-28
Filing date: 2008-09-25
Publication date: 2009-12-02

Abstract

The present invention relates to a kind of glycine and similar carboxylate salt also reclaim ammonia simultaneously with the acidifying of ammonium salt class Lewis acid novel technique.Invented with ammonium salt class Lewis acid (ammonium salts such as ammonium sulfate, monoammonium sulfate, ammonium chloride and composition thereof etc.) acidifying glycine and similar carboxylate salt and reclaimed the method for ammonia, can effectively reduce equipment corrosion and environmental pollution, reduce and produce investment and energy consumption, improve operating environment, improve the quality of products, reduce production costs, be more suitable for suitability for industrialized production.New process has alternative acid, can reclaim ammonia again, can also reduce the multiple effects that dewater such as water of productive use.

Description

The novel process for acidifying of glycin and other carboxylates

Technical field

The present invention proposes a kind of glycin and other carboxylates obtains glycine or corresponding carboxylic acid and reclaims the novel process of resolving ammonia simultaneously by the ammonium salt acidifying.This technology also is the another innovation for the direct ammonia of hydroxyacetonitrile is separated, alkaline hydrolysis, neutralization, purifying obtain the innovative approach of glycine.This technology not only can reduce cost, and can reduce the consumption of acid, also can be recovered as ammoniacal liquor or liquefied ammonia to the ammonium salt of low value simultaneously, a kind of novel process of killing two birds with one stone that reclaims ammonia from ammonium salt of can yet be regarded as.

Background technology

Amino acid such as glycine are the important source material of industry such as chemical industry, medicine, agricultural chemicals, have purposes widely.At present, have several different methods to produce glycine, defective such as wherein, the alpha-halogen acid system is domestic main industrialized preparing process, but has the lower defective of yield, and the catalyst recovery difficulty, and solvent consumption is big can not satisfy cleaner production and environmental protection requirement.By thanomin dehydrogenation in strong base solution, hydroxyacetonitrile ammonification alkaline hydrolysis obtains glycinate, uses mineral acid acidifyings such as hydrochloric acid, sulfuric acid again, and purifies and separates purification glycine is promising method.We had once proposed the easy new technology route that the direct ammonia of hydroxyacetonitrile is separated, the alkaline hydrolysis legal system is equipped with glycine in patent CN1990459A and CN1962611A, find the recovery set usefulness of inorganic salt and the yield of raising glycine, suppressed the generation of iminodiethanoic acid and easier separation and purification and clean preparation method.But in this technology, need use the sulfuric acid and the hydrochloric acid of equimolar amount at least, cause the cost height, the amount that concentrates when particularly using hydrochloric acid increases greatly.Because chemical raw material and energy prices skyrocket recently, cause ammonia, sulfuric acid and hydrochloric acid substantial appreciation of prices, the sour cost of the usefulness of acidification is higher.And ammonium chloride, sulphur ammonium are big as the byproduct output of a lot of industry such as soda ash, desulfurization, but use face is narrow, is worth low, wherein the most valuable ammonia resource is well recycled, if can make good use of acid wherein, reclaim ammonia wherein, then can promote its use value and economic benefit greatly.

At existing technical need, the present inventor has found the mixture of glycine ammonium or glycin and other carboxylates and ammonium salt through deep research, is easy to decompose steam ammonia under the situation of normal pressure or decompression heating.With ammonium salt or its mixtures such as ammonium chloride, ammonium sulfate, monoammonium sulfates, directly the acidifying glycinate carries out deamination, decolouring, purified crystals with ordinary method again, also can obtain pure product glycine very easily.The device of the synthetic glycine of former hydroxyl method just can use this novel process very easily hardly with changing.This technology not only can solve sulfuric acid acidation temperature height effectively, cause the corrosion and the damage of equipment easily, the hcl acidifying water yield is big, increase by two large-engineering problems such as the load of aftertreatment and energy consumption greatly, the working condition milder not only can reduce and use sour cost, and reclaims ammonia, and promote economic benefit greatly, meet the idea of development of recycling economy and raising atom utilization.

Summary of the invention

The purpose of this invention is to provide a kind of glycine and similar carboxylate salt with the acidifying of ammonium salt class Lewis acid and reclaim the novel technique of ammonia simultaneously.

The present invention also is the significant improvement to patent CN1990459A and CN1962611A preparing glycine by hydroxy acetonitrile method acidification technique.We find that under study for action amino acid salts and ammonium salt all are materials soluble in water, after two kinds of mixing of materials, can produce inorganic salt and solid thereof and replacement(metathesis)reaction takes place, by the heating deamination, replacement(metathesis)reaction is carried out thoroughly, and the free ammonia in the system can be reduced to below 0.1%.Obviously, the ammonium salt of amino acid and analogue under the situation of being heated, decomposite easily ammonia just can with ammonium salt as souring agent.

Specifically, the present invention has carried out following improvement to the acidization in the preparing glycine by hydroxy acetonitrile method alkali process:

1) with aminoacetonitriles and mineral alkali reaction, after obtaining containing the alkali solution liquid of glycinate, can not carry out deamination earlier and handle, but directly with above-mentioned alkali solution liquid with Lewis acid for example ammonium salt or its mixture elder generation mixed dissolutions such as ammonium sulfate, monoammonium sulfate, ammonium chloride, obtain ammonium salt mixture.

2) above-mentioned ammonium salt mixture is carried out deamination with conventional deamination equipment and condition and handle, just can access free ammonia and be lower than 0.1% the glycine and the mixture solution of inorganic salt.

3) said mixture solution has raw material composition and the character identical with former technology.Carry out aftertreatment by separation purifying process such as original decolouring, desalination, crystallizations, can obtain to conform with the glycine of specification of quality very easily.

The inventive method can adopt for example following specific embodiments:

1) hydroxyacetonitrile and excessive ammonia are reflected at directly add alkali after ammonification in 1 hour is finished about 50 ℃, at 60 ℃ of left and right sides alkaline hydrolysis after 2 hours, directly with for example ammonium salts such as ammonium sulfate, monoammonium sulfate, ammonium chloride and composition thereof acidifying of Lewis acid, lewis acidic consumption be in and the consumption of mineral alkali.

2) mixture that step 1) is obtained carries out deamination and handles, and deamination can carry out endpoint monitoring with pH, and preferred terminal point is near the iso-electric point, and available in case of necessity a small amount of acid-alkali accommodation pH to 5.5～6.5 obtain qualified deamination liquid.

3) with step 2) the deamination liquid that obtains, carry out aftertreatment with separation purifying process such as existing decolouring, desalination, crystallization, oven dry, can obtain qualified glycine.

In the present invention, described Lewis acid can be a kind of or its mixture in the ammonium salts such as ammonium sulfate, monoammonium sulfate, ammonium chloride, ammonium phosphate, ammonium hydrogen phosphate, primary ammonium phosphate, ammonium nitrate.Preferably ammonium chloride, ammonium sulfate and monoammonium sulfate etc.

During acidifying, lewis acidic consumption be in and the consumption of mineral alkali, mineral alkali: Lewis acid=1: 0.7-1.5 is preferably 1: 0.95-1.1.

Adopt above-mentioned reaction method can high yield, high purity, operation close friend, environmental friendliness, low cost, obtain glycine cleanly.

The inventive method has following advantage:

One, after the ammonification liquid caustic soda is separated, can take off most ammonia and directly add ammonium salt.

Two, the pattern of deamination after the first acidifying of this process using Lewis acid (ammonium salts such as ammonium sulfate, monoammonium sulfate, ammonium chloride and composition thereof), can effectively avoid after the acidifying ammonia not take off the acidizing fluid that causes to the greatest extent is difficult to decolouring, influences product purity and get brilliant rate, the reaction conditions gentleness, can avoid equipment to be corroded by strong acid, operational safety can be utilized original deamination equipment fully.

Three, use the ammonium chloride acidifying, can avoid bringing big water gaging into, the problem that causes facility investment increasing and energy consumption to increase with hcl acidifying.

Four, ammonium salt is as in the Lewis acid and glycinate, not only fully played sour effect, and can reclaim simultaneously valuable ammonia resource, as this technology prussic acid synthetic raw material, thus in the ammonium salt and technology be a good recycling economy technology of the high value added utilization of the acidifying of glycine and analogue salt thereof and ammonium salt.

Concrete reference examples

The preparation of reference examples 1 glycine

At room temperature in reactor, add 400 grams, 50% hydroxyacetonitrile solution, feed 237 gram ammoniacal liquor, react after 30 minutes, in aminating reaction liquid, add the 526g32% sodium hydroxide solution again, obtain the ammonia solution of glycine sodium salt in 40-80 ℃ of insulation 4-5h, deamination obtains the Sodium glycocollate salts solution, adds the mixing solutions that obtains glycine and inorganic salt sodium sulfate in the 210g98% sulfuric acid with acidifying subsequently.Add 20g activated carbon decolorizing postcooling to 10 ℃, crystallization, the centrifugal sodium sulfate crystal of removing, filtrate crystallization purifying according to a conventional method can get glycine solid 235～250g, and purity can reach more than 98.5%, rolls over hundred yields 90～95%.

The preparation of reference examples 2 glycine

At room temperature in reactor, add 400 grams, 50% hydroxyacetonitrile solution, feed 237 gram ammoniacal liquor, react after 30 minutes, in aminating reaction liquid, add the 526g32% sodium hydroxide solution again, obtain the ammonia solution of glycine sodium salt in 40-60 ℃ of insulation 4-5h, deamination obtains the Sodium glycocollate salts solution, adds in the 426.6g36% hydrochloric acid subsequently and acidifying, obtains the mixing solutions of glycine and inorganic salt sodium-chlor.After adding the 20g activated carbon decolorizing, be warming up to 90 ℃, be evaporated to crystal and separate out, filtered while hot is removed inorganic salt sodium-chlor, filtrate crystallization purifying according to a conventional method can obtain glycine solid 210～230g g, and purity 98.5～99.5% is rolled over hundred yield 78.6-86.1%.

Specific 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 237 gram ammoniacal liquor, react after 30 minutes, in aminating reaction liquid, add the 526g32% sodium hydroxide solution again, obtain the ammonia solution of glycine sodium salt in 40-60 ℃ of insulation 4-5h, add ammonium sulfate 280g subsequently, deamination, reclaim ammonia 71g, regulate about pH to 6, obtain the mixing solutions of glycine and sodium sulfate, be cooled to 10 ℃ behind the adding 20g activated carbon decolorizing, crystallization, remove sodium sulfate crystal, the filtrate heating concentrates and obtains glycine solution, and glycine solution crystallization purifying according to a conventional method can obtain glycine solid 230～250g, purity 98.5% is rolled over hundred yields 85～95%.

The preparation of embodiment 2 glycine

At room temperature in reactor, add 400 grams, 50% hydroxyacetonitrile solution, feed 237 gram ammoniacal liquor, react after 30 minutes, in aminating reaction liquid, add the 526g32% sodium hydroxide solution again, obtain the ammonia solution of glycine sodium salt in 40-60 ℃ of insulation 4-5h, add ammonium sulfate 280g subsequently, deamination, reclaim ammonia 70g, regulate about pH to 7, obtain the mixing solutions of glycine and sodium sulfate, add 20g activated carbon decolorizing post-heating to 80-100 ℃, condensing crystal, remove sodium sulfate crystal, the filtrate decrease temperature crystalline, crystallization purifying can obtain glycine solid 235～250gg according to a conventional method, purity 98.5% is rolled over hundred yields 90～95%.

The preparation of embodiment 3 glycine

At room temperature in reactor, add 400 grams, 50% hydroxyacetonitrile solution, feed 237 gram ammoniacal liquor, react after 30 minutes, in aminating reaction liquid, add the 526g32% sodium hydroxide solution again, obtain the ammonia solution of glycine sodium salt in 40-60 ℃ of insulation 4-5h, add monoammonium sulfate 244g subsequently, deamination, reclaim ammonia 35.5g, regulate about pH to 5, obtain the mixing solutions of glycine and sodium sulfate, add 20g activated carbon decolorizing post-heating to 80-100 ℃, condensing crystal, remove sodium sulfate crystal, the filtrate decrease temperature crystalline, crystallization purifying can obtain glycine solid 220g according to a conventional method, purity 98.5% is rolled over hundred yields 82.35%.

The preparation of embodiment 4 glycine

At room temperature in reactor, add 400 grams, 50% hydroxyacetonitrile solution, feed 237 gram ammoniacal liquor, react after 30 minutes, in aminating reaction liquid, add the 526g32% sodium hydroxide solution again, obtain the ammonia solution of glycine sodium salt in 40-60 ℃ of insulation 4-5h, add ammonium chloride 230g subsequently, deamination reclaims ammonia 71g, obtains the mixing solutions of glycine and sodium-chlor, regulate about pH to 5.5, add 20g activated carbon decolorizing post-heating to 80-100 ℃ of condensing crystal, remove sodium chloride crystal while hot, filtrate crystallization purifying according to a conventional method can obtain glycine solid 220～250g, purity 98.5% is rolled over hundred yield 82.5-95%.

Claims

1, the acidization in a kind of preparing glycine by hydroxy acetonitrile method alkali process is improved one's methods, and it comprises the steps:

1) with the reaction of aminoacetonitriles and mineral alkali, after obtaining containing the alkali solution liquid of glycinate, directly with above-mentioned alkali solution liquid with ammonium salt elder generation mixed dissolution, obtain ammonium salt mixture;

2) above-mentioned ammonium salt mixture is carried out deamination with conventional deamination equipment and condition and handle, obtain free ammonia and be lower than 0.1% the glycine and the mixture solution of inorganic salt;

3) said mixture solution obtains glycine by decolouring, desalination, crystallization treatment.

2, according to the process of claim 1 wherein:

1) hydroxyacetonitrile and excessive ammonia be reflected at directly add alkali after ammonification in 1 hour is finished about 50 ℃, after 2 hours, directly use the ammonium salt acidifying at 60 ℃ of left and right sides alkaline hydrolysis, the consumption of ammonium salt be in and the consumption of mineral alkali.

2) mixture that step 1) is obtained carries out deamination and handles, and deamination can carry out endpoint monitoring with pH, and available in case of necessity a small amount of acid-alkali accommodation pH to 5.5～6.5 obtain qualified deamination liquid.

3) with step 2) the deamination liquid that obtains, decolouring, desalination, crystallization, oven dry are handled, and obtain glycine.

3, according to the method for claim 1 or 2, wherein, ammonium salt is a kind of or its mixture in the ammonium salts such as ammonium sulfate, monoammonium sulfate, ammonium chloride, ammonium phosphate, ammonium hydrogen phosphate, primary ammonium phosphate, ammonium nitrate.

4, according to the method for claim 3, wherein, described ammonium salt is ammonium chloride, ammonium sulfate or monoammonium sulfate.

5, according to the arbitrary described method of claim 1-4, during acidifying, the consumption of ammonium salt be in and the consumption of mineral alkali, mineral alkali: ammonium salt=1: 0.7-1.5 is preferably 1: 0.95-1.1.

6, be near the iso-electric point with the terminal point of an amount of acid adjusting deamination liquid pH according to the arbitrary described method of claim 1-5, wherein, step 2).