JPS62148456A - Recovery of iminodiacetic acid - Google Patents

Recovery of iminodiacetic acid

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Publication number
JPS62148456A
JPS62148456A JP28920685A JP28920685A JPS62148456A JP S62148456 A JPS62148456 A JP S62148456A JP 28920685 A JP28920685 A JP 28920685A JP 28920685 A JP28920685 A JP 28920685A JP S62148456 A JPS62148456 A JP S62148456A
Authority
JP
Japan
Prior art keywords
alkali metal
acid
metal salt
iminodiacetic acid
iminodiacetic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP28920685A
Other languages
Japanese (ja)
Other versions
JPH0336824B2 (en
Inventor
Hideyuki Nishibayashi
秀幸 西林
Fumio Watanabe
文雄 渡辺
Takakiyo Goto
後藤 隆清
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Shokubai Co Ltd
Original Assignee
Nippon Shokubai Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Shokubai Co Ltd filed Critical Nippon Shokubai Co Ltd
Priority to JP28920685A priority Critical patent/JPS62148456A/en
Publication of JPS62148456A publication Critical patent/JPS62148456A/en
Publication of JPH0336824B2 publication Critical patent/JPH0336824B2/ja
Granted legal-status Critical Current

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  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

PURPOSE:To obtain the titled compound in high yield and purity, by adding sulfuric acid to an aqueous solution of mainly iminodiacetic acid alkali metal salt containing oxalic acid alkali metal salt, removing specific amount of precipitated alkali metal sulfate and adjusting the pH of the system to a specific level. CONSTITUTION:An aqueous solution of mainly iminodiacetic acid alkali metal salt containing oxalic acid alkali metal salt is added with sulfuric acid or an alkali metal sulfate to effect concentration and precipitation of an alkali metal sulfate at >=3.5pH. The amount of the precipitated alkali metal sulfate is >=25mol%, preferably >=30mol% based on the iminodiacetic acid salt. After removing the alkali metal sulfate by filtration, centrifugal separation, etc., the mother liquor is adjusted to 2.0-3.0pH with sulfuric acid to produce iminodiacetic acid, which is purified by fractional crystallization to recover iminodiacetic acid containing extremely small amount of oxalic acid and/or oxalic acid alkali metal salt.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明はシュウ酸のアルカリ金属塩を含む主としてイミ
ノジ酢酸アルカリ金属塩からなる水溶液よりシュウ酸お
よび/またはシュウ酸のアルカリ金属塩の含量の極めて
少ないイミノジ醋酸を高収率で回収する方法に関する。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is aimed at reducing the content of oxalic acid and/or alkali metal salts of oxalic acid to a much higher level than in an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid. This invention relates to a method for recovering a small amount of iminodiacetic acid with high yield.

(従来の技術) イミノジ酢酸はキレート剤、キレート樹脂原料、染色助
剤、洗剤用ビルダー等のキレート作用を利用する用途だ
【ノでなく、医薬、葭45の原料としても有用な化合物
である。
(Prior art) Iminodiacetic acid is used not only as a chelating agent, raw material for chelate resin, dyeing aid, and builder for detergents using its chelating action, but also as a useful compound for medicine and as a raw material for Yoshi 45.

従来、イミノジ酢酸は、グリシンとグリー]1]ニトリ
ルの反応、アンモニア、シアン化水索及びホルムアルデ
ヒドの反応、アンモニアとセノクロル酢酸の反応により
合成されていたが、これらの方法ではイミノジ醋酸との
分N1が困難なニトリ[1トリ酢酸の副生が避けられず
、イミノジ酢酸を高純度、高収率で1!することは困デ
「であった。
Conventionally, iminodiacetic acid has been synthesized by the reaction of glycine and glycine [1] nitrile, the reaction of ammonia, cyanide water, and formaldehyde, and the reaction of ammonia and senochloroacetic acid. The by-product of nitriacetic acid [1], which is difficult to produce, cannot be avoided, and iminodiacetic acid can be produced with high purity and high yield. It was difficult to do so.

このような点から、現在ジェタノールアミンのアルカリ
金属水酸化物存在下での脱水素あるいは空気酸化ににる
ニトリロトリ酢酸を含まないイミノジ醋酸の合成法が注
目されている。しかし、この場合には副反応により毒性
で問題のあるシュウ酸が生成する。従って、このような
反応により1qられるイミノジ酢酸アルカリ金属塩水溶
液からイミノジ酢酸を高純度で回収しようとザる場合、
まず硫酸、塩酸等の無機酸で中和し、生成する無機塩が
沈殿しない条件、すなわち糧めて薄い濃度下で分別しな
【プればならない、その場合回収されるイミノジ酢酸は
高純度で得られるが回収率が著しく低くなり経済的でな
い。
From this point of view, a method of synthesizing iminodiacetic acid that does not contain nitrilotriacetic acid, which involves dehydrogenation of jetanolamine in the presence of an alkali metal hydroxide or air oxidation, is currently attracting attention. However, in this case, oxalic acid, which is toxic and problematic, is produced due to side reactions. Therefore, when trying to recover iminodiacetic acid in high purity from an aqueous solution of alkali metal iminodiacetic acid produced by 1q by such a reaction,
First, the iminodiacetic acid recovered must be neutralized with an inorganic acid such as sulfuric acid or hydrochloric acid, and fractionated under conditions in which the formed inorganic salt does not precipitate, that is, at a very low concentration. However, the recovery rate is extremely low and it is not economical.

また、シュウ酸をカルシウム塩、バリウム塩等の沈殿剤
を用いで、水不溶性のjnとして除去する方法はシュウ
酸に対して大過剰mの沈殿剤が必要となるばかりでなく
、析出する沈殿中にはシュウ酸塩だけでなく多山のイミ
ノジ酢酸塩が含まれることとなり、回収ヰ町が低くしか
も高純度のものが得られないという欠点があった。
In addition, the method of removing oxalic acid as water-insoluble jn using a precipitant such as a calcium salt or barium salt not only requires a large excess of the precipitant to the oxalic acid, but also contains not only oxalate but also a large amount of iminodiacetate, which has the disadvantage that the recovery rate is low and high purity cannot be obtained.

(発明が解決しようと16問題点) 本発明の目的は、上記問題点を解消するためのものであ
り、より詳しくはシュウ酸のアルカリ金属塩を含むイミ
ノジ酢酸アルカリ金属塩水溶液より、イミノジ酢酸を高
純度に効率よく回収する方法を提供することにある。
(16 Problems to be Solved by the Invention) The purpose of the present invention is to solve the above-mentioned problems. More specifically, it is an object of the present invention to solve the above-mentioned problems. The objective is to provide a method for efficiently recovering high purity.

(問題を解決するための手段および作用)本発明は、シ
ュウ酸のアルカリ金属塩を含む主としてイミノジ酢酸ア
ルカリ金属塩からなる水溶液よりシュウ酸および/また
はシュウ酸のアルカリ金属塩の含量の極めて少ないイミ
ノジ酢酸を高収率で回収する方法において、シュウ酸の
アルカリ金属塩を含む主としてイミノジ酢酸アルカリ金
属塩からなる水溶液に硫酸および/またはU7.を酸の
アルカリ金属塩水溶液を添加しOH3,5以上の条件下
イミノジ酢FiIInに対して25モル%以上に相当す
る硫酸のアルカリ金属塩を濃縮析出させ、硫酸のアルカ
リ金属塩を除去した後、次いで該母液を硫酸でp H2
,0〜3.0とし、イミノジ酢酸を生成させこれを分別
晶析することを特徴とするイミノジ酢酸の回収方法に関
するものである。
(Means and Effects for Solving the Problems) The present invention provides an iminodiacetic acid solution containing extremely less oxalic acid and/or an alkali metal salt of oxalate than an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid. In a method for recovering acetic acid in high yield, sulfuric acid and/or U7. After adding an aqueous solution of an alkali metal salt of an acid and concentrating and precipitating an alkali metal salt of sulfuric acid corresponding to 25 mol% or more based on FiIn in iminodiacetic acid under OH 3.5 or higher, and removing the alkali metal salt of sulfuric acid, The mother liquor was then adjusted to pH2 with sulfuric acid.
, 0 to 3.0, and relates to a method for recovering iminodiacetic acid, which is characterized by producing iminodiacetic acid and separately crystallizing it.

本発明はシュウ酸のアルカリ金属塩を含む主としてイミ
ノジ酢酸アルカリ金属塩からなる水溶液よりシュウ酸お
よび/またはシュウ酸のアルカリ金属塩の含ωの極めて
少ないイミノジ酢酸を高収率で回収する方法において、
アルカリ金属塩がナトリウム塩または/およびカリウム
塩である場合特に有効である。
The present invention provides a method for recovering iminodiacetic acid with an extremely low content of oxalic acid and/or an alkali metal salt of oxalic acid in a high yield from an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid.
It is particularly effective when the alkali metal salt is a sodium salt or/and a potassium salt.

以下、本発明を説明する。The present invention will be explained below.

ジェタノールアミンをアルカリ金属水酸化物の存在下脱
水素あるいは空気酸化すると、シュウ酸のアルカリ金属
塩がかなりの偵生成するが、この反応生成液系において
はシュウ酸のアルカリ金属塩は過飽和状態ぐ艮明間安定
に存在し、このまま硫酸で中和しイミノジ酢酸を晶析さ
せると、シュウ酸がかなりのM不純物として含まれてし
まう。
When jetanolamine is dehydrogenated or air oxidized in the presence of an alkali metal hydroxide, a considerable amount of alkali metal salts of oxalic acid are produced, but in this reaction product system, the alkali metal salts of oxalic acid are in a supersaturated state. It exists in a stable manner, and if it is neutralized with sulfuric acid to crystallize iminodiacetic acid, a considerable amount of oxalic acid will be included as an M impurity.

本発明のシュウ酸のアルカリ金属塩を含む主としてイミ
ノジ酢酸アルカリ金I+1塩からなる水溶液よりシュウ
酸および/またはシュウ酸のアルカリ金属塩の含量の極
めて少ないイミノジ酢酸を高収率で回収する方法におい
て、シュウ酸のアルカリ金属塩を含む主としてイミノジ
酢酸アルカリ金属塩からなる水溶液に硫酸あるいは硫酸
のアルカリ金B塩水溶液を添加し、その溶液のp l−
1を3.5以上に保つ必要がある。
In the method of recovering iminodiacetic acid with a very low content of oxalic acid and/or alkali metal salt of oxalic acid in a high yield from an aqueous solution mainly consisting of an alkali gold I+1 salt of iminodiacetic acid containing an alkali metal salt of oxalic acid according to the present invention, Sulfuric acid or an aqueous alkali gold B salt solution of sulfuric acid is added to an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid, and the p l-
It is necessary to keep 1 above 3.5.

溶液のpHが3.5未満で硫酸のアルカリ金属塩を析出
させようとすると難溶性であるイミノジ酢酸が析出する
硫酸のアルカリ金属塩に混入するためイミノジ酢酸の回
収率が低くなる。これを防止するために水の除去徂を少
なくすると硫酸のアルカリ金属塩の析出nをイミノジ酢
Pl!2塩に対し25七ル%以上析出させることができ
ないため、逆にシュウ酸の除去が不充分となり高純度の
イミノジ酢酸は得られない。
If an attempt is made to precipitate the alkali metal salt of sulfuric acid when the pH of the solution is less than 3.5, the recovery rate of iminodiacetic acid will be low because poorly soluble iminodiacetic acid will be mixed into the precipitated alkali metal salt of sulfuric acid. To prevent this, reducing the amount of water removed will prevent the precipitation of the alkali metal salt of sulfuric acid. Since it is not possible to precipitate more than 257% of the 2-salt, on the contrary, oxalic acid is insufficiently removed and iminodiacetic acid of high purity cannot be obtained.

本発明のシュウ酸のアルカリ金属塩を含む主としてイミ
ノジ酢酸アルカリ金属塩からなる水溶液よりシュウ酸お
よび/またはシュウ酸のアル−カリ金fiX j’Aの
含量の極めて少ないイミノジ酢酸を高収率で回収する方
法において、シュウ酸のアルカリ金属塩を含む主として
イミノジ酢酸アルク」り金属塩からなる水溶液に硫酸あ
るいは硫酸のアルカリ金属塩水溶液を添加しp l−1
3,5以上の条+’l下、イミノジ酢酸塩に対して25
モル%以上、好ましくは30モル%以上に相当する硫酸
のアルbり金属塩を濃縮析出させることが必要である。
Iminodiacetic acid having an extremely low content of oxalic acid and/or alkali gold fiX j'A of oxalic acid is recovered in high yield from an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid according to the present invention. In this method, sulfuric acid or an aqueous solution of an alkali metal salt of sulfuric acid is added to an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid.
25 for iminodiacetate under conditions of 3,5 or more +'l
It is necessary to concentrate and precipitate the alkali metal salt of sulfuric acid corresponding to mol% or more, preferably 30 mol% or more.

づなわちこのような系に硫酸あるいはriAaのアルカ
リ金属塩水溶液を添加しpH3,5以上の条件下イミノ
ジ[アルカリ金属塩に対して25モル%以上に相当する
硫酸ナトリウムを濃縮析出させることによりシュウ酸ナ
トリウムの過飽和状態は短期間で解消される。
In other words, sulfuric acid or an aqueous solution of an alkali metal salt of riAa is added to such a system, and sodium sulfate corresponding to 25 mol% or more relative to the alkali metal salt is concentrated and precipitated under conditions of pH 3.5 or higher. The supersaturation state of sodium chloride is resolved in a short period of time.

しかし、析出させる硫酸のアルカリ金属塩の口がイミノ
ジ酢酸アルカリ金属塩に対し25モル%J、り低い場合
にはシュウ酸のアルカリ金属塩の過飽和状態はまだ充分
に解消されず、このままで次のイミノジ酢酸の析出の工
程に移るとイミノジ酢酸結晶中にシュウ酸および/また
はシュウ酸のアルク」り金属塩が混入し、目的とする高
純度のイミノジ酢酸は1すられず、シュウ酸および/ま
たはシュウ酸のアルカリ金属1酷の混入をさせないため
には、イミノジ酢酸析出時に5吊の水を添カロしてやら
なければならず、結果としてイミノジ酢酸の回収率が低
くなる。
However, if the alkali metal salt of sulfuric acid to be precipitated is 25 mol% J lower than the alkali metal salt of iminodiacetic acid, the supersaturation state of the alkali metal salt of oxalic acid will not be sufficiently eliminated, and the next step will be carried out as it is. When moving on to the step of precipitation of iminodiacetic acid, oxalic acid and/or an alkali metal salt of oxalic acid are mixed into the iminodiacetic acid crystals, and the desired high-purity iminodiacetic acid is not obtained. In order to prevent significant contamination of alkali metals in the acid, it is necessary to add water at the time of precipitation of iminodiacetic acid, resulting in a low recovery rate of iminodiacetic acid.

本発明において析出した硫酸およびシュウ酸のアルカリ
金属塩等の除去は通常の方法たとえばか過、遠心分離、
デカンタ−等により行なうことができる。 本発明のシ
ュ・り酸のアルカリ金11i塩を含む主としてイミノジ
酢酸アルカリ金1i1 Inからなる水溶液よりシュウ
酸および/またはシュウ酸のアルカリ金属塩の含量の極
めて少ないイミノジ酢酸を高収率で回収する方法におい
て、シュウ酸のアルカリ金属塩を含む主としてイミノジ
酢酸アルカリ金属塩からなる水溶液に硫酸あるいは硫酸
のアルカリ金a塩水溶液を添加しD H3,5以上の条
件下、イミノジ酢酸塩に対して25モル%以上に相当す
る!iI!l酸のアルカリ金属塩を濃縮析出さ往、硫酸
のアルカリ金属塩を除去した後、次いで該母液を硫酸で
p t−12,0〜3.0にすることが必要である。
In the present invention, the precipitated alkali metal salts of sulfuric acid and oxalic acid can be removed by conventional methods such as filtration, centrifugation,
This can be done using a decanter or the like. Iminodiacetic acid having an extremely low content of oxalic acid and/or an alkali metal salt of oxalic acid is recovered in high yield from an aqueous solution mainly consisting of an alkali gold 1i1 In iminodiacetate containing an alkali gold 11i salt of oxalic acid according to the present invention. In the method, sulfuric acid or an aqueous alkali gold a salt solution of sulfuric acid is added to an aqueous solution mainly consisting of an alkali metal salt of iminodiacetate containing an alkali metal salt of oxalic acid, and 25 mol based on the iminodiacetate is added under conditions of D H3.5 or higher. Equivalent to more than %! iI! After concentrating and precipitating the alkali metal salts of 1 acid and removing the alkali metal salts of sulfuric acid, it is then necessary to bring the mother liquor to pt-12.0 to 3.0 with sulfuric acid.

この操作によりシュウ酸および硫酸のアルカリ金属塩の
この水溶液系における溶解度は増大するため析出するイ
ミノジ酢酸は高純度のものとなる。
This operation increases the solubility of the alkali metal salts of oxalic acid and sulfuric acid in this aqueous solution system, so that the iminodiacetic acid precipitated has a high purity.

析出したイミノジ酢酸は同様にか過、遠心分離、デhン
ター等により容易に分離することができる。
The precipitated iminodiacetic acid can be similarly easily separated by filtration, centrifugation, dehintering, etc.

この際pHが3.0より高いとイミノジ酢酸の回収率が
低くなり、p[−1が2.0よりも低いとこの場合にも
イミノジ酢酸の回収率が悪くなり、しかも製品乾燥時に
着色等の問題が起こることがある。
In this case, if the pH is higher than 3.0, the recovery rate of iminodiacetic acid will be low, and if p[-1 is lower than 2.0, the recovery rate of iminodiacetic acid will be low in this case as well, and coloring etc. may occur during product drying. problems may occur.

イミノジ酢酸を分離した上記母液はそのまま廃棄しても
よいが、イミノジ酢酸の回収率をさらに向上させるため
には全通あるいは一部を再循環して使用するのが望まし
い。
The mother liquor from which iminodiacetic acid has been separated may be disposed of as is, but in order to further improve the recovery rate of iminodiacetic acid, it is desirable to recirculate all or part of it for use.

なお、本発明においてはジェタノールアミン中ジェタノ
ールアミン中の不純物のモノエタノールアミンあるいは
副反応に起因するグリシンはイミノジ酢酸の回収率およ
びイミノジ酢酸の純度に1すら悪影響を及ぼさない。な
ぜならグリシンはpl−12,0〜3.0というイミノ
ジ酢酸析出条件ではイミノジ酢酸に比べ非常に大きな溶
wi麿であり、母液中に残留するからである。
In the present invention, monoethanolamine as an impurity in jetanolamine or glycine resulting from a side reaction does not have even the slightest adverse effect on the recovery rate of iminodiacetic acid and the purity of iminodiacetic acid. This is because glycine is much more soluble than iminodiacetic acid under the iminodiacetic acid precipitation conditions of pl-12.0 to 3.0, and remains in the mother liquor.

(作 用) 本発明は、シュウ酸のアルカリ金属塩を含む主としてイ
ミノジ酢酸アルカリ金属塩からなる水溶液よりシュウ酸
および/またはシュウ酸のアルカリ金属塩の含■の極め
て少ないイミノジ酢酸を高収率で回収する方法において
、シュウ酸のアルカリ金属塩を含む主としてイミノジ酢
酸アルカリ金属塩からなる水溶液に硫酸あるいは硫酸の
アルカリ金属塩水溶液を添加しp H3,5以上の条件
下イミノジl’lVFm jnに対して25モル%以上
に相当する硫酸のアルカリ金属塩を濃縮析出さけ、硫酸
のアルカリ金属塩を除去した後、次いで該母液を硫酸で
p l−12,0〜3.0とすることにより、イミノジ
酢酸を高純度に効率よく回収する作用を提供できるもの
である。
(Function) The present invention produces iminodiacetic acid with extremely low content of oxalic acid and/or an alkali metal salt of oxalic acid in a high yield than an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid. In the recovery method, sulfuric acid or an aqueous solution of an alkali metal salt of sulfuric acid is added to an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid, and the reaction is carried out under conditions of pH 3.5 or higher. After concentrating and precipitating the alkali metal salt of sulfuric acid corresponding to 25 mol% or more and removing the alkali metal salt of sulfuric acid, the mother liquor was then adjusted to a pH of 12.0 to 3.0 with sulfuric acid to obtain iminodiacetic acid. It is possible to provide the effect of efficiently recovering high-purity substances.

(実 施 例) 以下、実施例を挙げて、本発明の実施の態様を具体的に
例示して説明する。本発明はこれらの実施例に限定され
るものではない。
(Example) Hereinafter, embodiments of the present invention will be specifically illustrated and described with reference to Examples. The present invention is not limited to these examples.

実施例 1 ジェタノールアミンを水酸化ナトリウムの存在下脱水素
し、イミノジ酢酸二ナトリウム20.1重最%、シュウ
酸ナトリウム0.4重量%、グリシンナトリウム0.3
 I ffi%、水酸化ナトリウム0.4 ffl#t
%の組成の水溶液が得られた。
Example 1 Jetanolamine was dehydrogenated in the presence of sodium hydroxide to produce 20.1% by weight of disodium iminodiacetate, 0.4% by weight of sodium oxalate, and 0.3% by weight of sodium glycine.
I ffi%, sodium hydroxide 0.4 ffl#t
An aqueous solution with a composition of % was obtained.

コ(7)水溶液2000gに98tfxf’a%la酸
126(コを加えpl−1を6.4とした。この溶液か
ら減圧上加熱し水を13360除去し、80℃以上で析
出したIaMナトリウムを遠心分離した。この際析出し
たF、M Mナトリウムの吊は150qであり、イミノ
ジ酢酸ナトリウムに対し43モル%であった。
98 tfxf'a%la acid 126 (co) was added to 2000 g of the aqueous solution (7) to make pl-1 6.4. From this solution, 13360 ml of water was removed by heating under reduced pressure, and the IaM sodium precipitated at 80°C or higher. The mixture was centrifuged.The weight of sodium F, MM precipitated at this time was 150q, and was 43 mol% relative to sodium iminodiacetate.

また、1」液中のシュウ酸ナトリウム濃度は0.07重
量%であった。さらにこの母液に水1ooaを添加した
後98重量%硫酸114qでp H2,4とした。この
液を40℃まで冷JJ] L析出したイミノジ酢酸を遠
心分離した後イミノジ酢酸の結晶を水洗した。結晶を1
10℃3時間乾燥し254gのイミノジ酢酸を19だ。
Further, the sodium oxalate concentration in the 1'' liquid was 0.07% by weight. Furthermore, 100 a of water was added to this mother liquor, and the pH was adjusted to 2.4 with 114 q of 98% sulfuric acid. This solution was cooled to 40° C. The precipitated iminodiacetic acid was centrifuged, and the iminodiacetic acid crystals were washed with water. 1 crystal
Dry at 10°C for 3 hours to obtain 254g of iminodiacetic acid.

このイミノジ酢酸中の硫酸ナトリウムは0.05重M%
であり、シュウ酸及びグリシンは検出されなかった。
Sodium sulfate in this iminodiacetic acid is 0.05% by weight
However, oxalic acid and glycine were not detected.

イミノジ酢酸の回収率は84.jモル%であった。The recovery rate of iminodiacetic acid was 84. j mol%.

実施例 2 ジェタノールアミンを水酸化ナトリウムの存在下脱水素
し、イミノジ酢酸二ナトリウム20.11α%、シュウ
酸ナトリウム0.41 fM%、グリシンナトリウム0
.3 重fa%、水酸化ナトリウム0.4車量%の組成
の水溶液が得られた。
Example 2 Jetanolamine was dehydrogenated in the presence of sodium hydroxide, disodium iminodiacetate 20.11α%, sodium oxalate 0.41 fM%, sodium glycine 0
.. An aqueous solution having a composition of 3% by weight of fa and 0.4% by weight of sodium hydroxide was obtained.

この水溶液2000Gに実施例1で得られたイミノジ酢
酸回収後の母液700Qを加えた。
To 2000G of this aqueous solution was added 700Q of the mother liquor obtained in Example 1 after recovery of iminodiacetic acid.

この母液中にはイミノジ酢酸が31 Q 、 l+a酸
ナトリウムが1780含まれていた。
This mother liquor contained 31 Q of iminodiacetic acid and 1780 Q of sodium l+a acid.

以下この液を用い実施例1と同様の操作を行ない、29
0qの硫酸ナトリウムすなわちイミノジ酢酸ナトリウム
に対し82モル%を析出した。この母液中のシュウ酸ナ
トリウム濃度は0.06重倒%であった。以下同様の操
作を行ない、286qのイミノジ酢酸を得た。このイミ
ノジ酢酸中の硫酸ナトリウムは0.05重量%であり、
シュウ酸及びグリシンは検出されなかった。
Hereinafter, the same operation as in Example 1 was carried out using this liquid, and 29
82 mol% was precipitated based on 0q of sodium sulfate, that is, sodium iminodiacetate. The sodium oxalate concentration in this mother liquor was 0.06% by weight. The same operation was performed thereafter to obtain 286q of iminodiacetic acid. Sodium sulfate in this iminodiacetic acid is 0.05% by weight,
Oxalic acid and glycine were not detected.

イミノジ酢酸の回収率は新たに供給したイミノジ酢酸を
基準として94.7モル%であった。
The recovery rate of iminodiacetic acid was 94.7 mol% based on the newly supplied iminodiacetic acid.

実施例 3 ジェタノールアミンを水酸化ナトリウムの存在下1悦水
素し、イミノジ酢酸二ノ′]ヘリウム20.1小16%
、シュウ酸ナトリウム0.4 重量%、グリランナ1〜
リウム0.3 ffl ;1%、水酸化ナトリウム0.
4壬1u%の組成の水溶液が1!7られた。この水溶液
20o OQ t、:tta酸ナトナトリウム10 G
を含む水溶液500gを加えた。
Example 3 Jetanolamine was hydrogenated in the presence of sodium hydroxide, and 20.1% dino']helium iminodiacetate was added.
, Sodium oxalate 0.4% by weight, Grillanna 1~
Lithium 0.3 ffl; 1%, sodium hydroxide 0.
An aqueous solution having a composition of 4 liters and 1 u% was prepared. This aqueous solution 20o OQ t: sodium ttarate 10G
500 g of an aqueous solution containing was added.

この溶液から水1590Qをを除去し80℃以上で析出
した(d酸ナトリウムを遠心分離した。この際41i出
した!IA 閣ナトリウムの16は93gであり、イミ
ノジ酢酸ナトリウムに対し29モル%であった。また母
液中のシュウ酸ナトリウム濃度tよ0:10重量%であ
った。
Water 1590Q was removed from this solution and precipitated at 80°C or higher (sodium d-acid was centrifuged. At this time, 41i was released! IA cabinet sodium 16 weighed 93 g, which was 29 mol% based on sodium iminodiacetate. The concentration of sodium oxalate in the mother liquor was 0:10% by weight.

さらにこの母液に水510gを添加した後98俳m%硫
1liII240 a T: p H2,4ニL タ。
Furthermore, after adding 510 g of water to this mother liquor, 98 m% sulfur was added.

コ(1) N ヲ40℃まで冷却し析出したイミノジ酢
酸を遠心分離した後、イミノジ酢酸の結晶を水洗した。
(1) N After cooling to 40° C. and centrifuging the precipitated iminodiacetic acid, the iminodiacetic acid crystals were washed with water.

結晶を110℃3時間乾燥し202gのイミノジ酢酸を
得た。このイミノジ酢酸中の硫酸ナトリウムは0.08
重伍%であり、シュウ酸及びグリシンは検出されなかっ
た。
The crystals were dried at 110° C. for 3 hours to obtain 202 g of iminodiacetic acid. The sodium sulfate in this iminodiacetic acid is 0.08
%, and oxalic acid and glycine were not detected.

イミノジ酢酸の回収率は66.9モル%であった。The recovery rate of iminodiacetic acid was 66.9 mol%.

比較例 1 ジェタノールアミンを水酸化ナトリウムの存在下脱水素
し、イミノジ酢酸二ナトリウム20.1 Llli■%
、シュウ酸ナトリウム0.4重ω%、グリシンナトリウ
ム0.3 ffl ff1%、水酸化ナトリウム0.4
市ω%の組成の水溶液が得られた。
Comparative Example 1 Jetanolamine was dehydrogenated in the presence of sodium hydroxide to yield 20.1 Llli% disodium iminodiacetate.
, sodium oxalate 0.4w%, sodium glycine 0.3 ffl ff1%, sodium hydroxide 0.4
An aqueous solution having a composition of %% was obtained.

この水溶液2000Qに98小ii1%硫酸126qを
加えpHを6.4とした。この溶液から減圧上加熱し水
を590q除去し、80℃以上で析出した(a Fli
ナトリウムを遠心分離した。この際析出した硫酸ナトリ
ウムの吊は61gであり、イミノジ酢酸ナトリウムに対
し19モル%であった。また、母液中のシュウ酸ナトリ
ウム濃度は0.19申罎%であった。
To this aqueous solution 2000Q, 126q of 1% sulfuric acid was added to adjust the pH to 6.4. This solution was heated under reduced pressure to remove 590q of water, and precipitated at 80°C or higher (a Fli
The sodium was centrifuged off. The amount of sodium sulfate precipitated at this time was 61 g, which was 19 mol % based on sodium iminodiacetate. Further, the concentration of sodium oxalate in the mother liquor was 0.19%.

さらにこの母液に水500qを添加した後、98千m%
硫酸114qでpH2,4とした。この液を40℃まで
冷却し析出したイミノジ酢酸を遠心分離した後、イミノ
ジ酢酸の結晶を水洗した。結晶を110℃3時間乾燥し
162qのイミノジ酢酸を1qた。このイミノジ酢酸中
のlaMナトリウムは0.06重■%であり、シュウ酸
及びグリシンは検出されなかった。
Furthermore, after adding 500q of water to this mother liquor, 98,000 m%
The pH was adjusted to 2.4 with 114q of sulfuric acid. This liquid was cooled to 40° C., and the precipitated iminodiacetic acid was centrifuged, and then the iminodiacetic acid crystals were washed with water. The crystals were dried at 110°C for 3 hours to yield 1q of 162q of iminodiacetic acid. The laM sodium in this iminodiacetic acid was 0.06% by weight, and oxalic acid and glycine were not detected.

イミノジ酢酸の回収Σ斜は54モル%であった。The recovery Σ slope of iminodiacetic acid was 54 mol%.

(′R,明の効果) 本発明は、シュウ酸のアルカリ金属塩を含む主としてイ
ミノジ酢酸アルカリ金属塩からなる水溶8欠よりシュウ
酸お」、び/まtこはシュウ酸のアルカリ金属塩の含)
3の極めて少ないイミノジNI Mを高収率で回収する
方法に(6いて、シュウ酸のアル)Jり金属塩を含む主
としてイミノジ酢酸アルカリ金属塩からなる水溶液に硫
酸および/または硫酸のアルカリ金属塩水溶液を添加し
o )−13,5以−Fの条件下イミノジ酢酸塩に対し
て25℃ル%以上に相当する硫酸のアルカリ金属塩を凝
縮析出させ、硫酸のアルカリ金属塩を除去した後、次い
で該母液を(1[でl) H2,O〜3.0とすること
により、イミノジ酢酸を高純度に効率よく回収する効果
を提供できるものである。
('R, bright effect) The present invention is characterized in that oxalic acid is produced from a water-soluble 8-diacetate mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid. (including)
A method for recovering extremely small amount of iminodiacetic acid in a high yield (6) is to add sulfuric acid and/or an alkali metal salt of sulfuric acid to an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid. After adding an aqueous solution and condensing and precipitating an alkali metal salt of sulfuric acid corresponding to 25°C or more of the iminodiacetate under conditions of -13,5 or more -F, and removing the alkali metal salt of sulfuric acid, Then, by adjusting the mother liquor to (1 [in l) H2,O~3.0], it is possible to provide the effect of efficiently recovering iminodiacetic acid with high purity.

Claims (1)

【特許請求の範囲】[Claims] (1)シュウ酸のアルカリ金属塩を含む主としてイミノ
ジ酢酸アルカリ金属塩からなる水溶液よりシュウ酸およ
び/またはシュウ酸のアルカリ金属塩の含量の極めて少
ないイミノジ酢酸を高収率で回収する方法において、シ
ュウ酸のアルカリ金属塩を含む主としてイミノジ酢酸ア
ルカリ金属塩からなる水溶液に硫酸および/または硫酸
のアルカリ金属塩水溶液を添加しpH3.5以上の条件
下、イミノジ酢酸塩に対して25モル%以上に相当する
硫酸のアルカリ金属塩を濃縮析出させ、硫酸のアルカリ
金属塩を除去した後、次いで該母液を硫酸でpH2.0
〜3.0とし、イミノジ酢酸を生成させ分別晶析するこ
とを特徴とするイミノジ酢酸の回収方法。
(1) A method for recovering iminodiacetic acid with a very low content of oxalic acid and/or an alkali metal salt of oxalic acid in a high yield from an aqueous solution mainly consisting of an alkali metal salt of iminodiacetic acid containing an alkali metal salt of oxalic acid. Add sulfuric acid and/or an aqueous solution of an alkali metal salt of sulfuric acid to an aqueous solution containing an alkali metal salt of an acid and mainly consisting of an alkali metal salt of iminodiacetate, and under conditions of pH 3.5 or higher, the amount corresponds to 25 mol% or more based on the iminodiacetate. After concentrating and precipitating the alkali metal salt of sulfuric acid and removing the alkali metal salt of sulfuric acid, the mother liquor was adjusted to pH 2.0 with sulfuric acid.
~3.0, and is characterized by producing iminodiacetic acid and performing fractional crystallization.
JP28920685A 1985-12-24 1985-12-24 Recovery of iminodiacetic acid Granted JPS62148456A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP28920685A JPS62148456A (en) 1985-12-24 1985-12-24 Recovery of iminodiacetic acid

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP28920685A JPS62148456A (en) 1985-12-24 1985-12-24 Recovery of iminodiacetic acid

Publications (2)

Publication Number Publication Date
JPS62148456A true JPS62148456A (en) 1987-07-02
JPH0336824B2 JPH0336824B2 (en) 1991-06-03

Family

ID=17740149

Family Applications (1)

Application Number Title Priority Date Filing Date
JP28920685A Granted JPS62148456A (en) 1985-12-24 1985-12-24 Recovery of iminodiacetic acid

Country Status (1)

Country Link
JP (1) JPS62148456A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160345202A1 (en) * 2015-05-22 2016-11-24 Qualcomm Incorporated Techniques for signal extension signaling

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160345202A1 (en) * 2015-05-22 2016-11-24 Qualcomm Incorporated Techniques for signal extension signaling

Also Published As

Publication number Publication date
JPH0336824B2 (en) 1991-06-03

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