JPH0717902A - Method for treating mother liquid separated from high-purity terephthalic acid - Google Patents
Method for treating mother liquid separated from high-purity terephthalic acidInfo
- Publication number
- JPH0717902A JPH0717902A JP16338593A JP16338593A JPH0717902A JP H0717902 A JPH0717902 A JP H0717902A JP 16338593 A JP16338593 A JP 16338593A JP 16338593 A JP16338593 A JP 16338593A JP H0717902 A JPH0717902 A JP H0717902A
- Authority
- JP
- Japan
- Prior art keywords
- acid
- terephthalic acid
- mother liquor
- separated
- mother liquid
- 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.)
- Pending
Links
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はテレフタル酸の製造法に
関し、詳しくは高純度テレフタル酸を晶析させ結晶を分
離する際に得られる分離母液の処理方法に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing terephthalic acid, and more particularly to a method for treating a separated mother liquor obtained when crystallizing high-purity terephthalic acid to separate crystals.
【０００２】[0002]
【従来の技術】テレフタル酸はパラキシレンなどのｐ−
ジアルキルベンゼン類を酸化して製造され、通常は酢酸
を溶媒として、コバルト、マンガン等の重金属触媒、ま
たはこれに臭素化合物、或いはアセトアルデヒドのよう
な促進剤を加えた触媒が用いられる。液相酸化によって
得られる粗テレフタル酸は、通常4-カルボキシベンズア
ルデヒト（４ＣＢＡ）、パラトルイル酸および安息香酸
などの不純物を多量に含んでおり、このままグリコール
と反応させてポリエステルとするには適さない。2. Description of the Related Art Terephthalic acid is p-type such as paraxylene.
It is produced by oxidizing dialkylbenzenes, and usually a heavy metal catalyst such as cobalt or manganese, or a catalyst obtained by adding a bromine compound or a promoter such as acetaldehyde to acetic acid is used as a solvent. Crude terephthalic acid obtained by liquid phase oxidation usually contains a large amount of impurities such as 4-carboxybenzaldecht (4CBA), paratoluic acid and benzoic acid, and is not suitable for reacting with glycol to give polyester.
【０００３】このように不純物を含む粗テレフタル酸か
ら高純度テレフタル酸を製造する方法としては、粗テレ
フタル酸の水溶媒スラリーを加熱・溶解して接触処理す
る方法（特公昭49-33189号等) 、水素化還元処理を行う
方法 (特公昭41-16860号、特公昭51-32618号、特公昭51
-38698号等) 等が知られている。As a method for producing high-purity terephthalic acid from crude terephthalic acid containing impurities, a method of heating and dissolving a slurry of crude terephthalic acid in an aqueous solvent to carry out contact treatment (Japanese Patent Publication No. 49-33189 etc.) , A method of performing a hydrogenation reduction treatment (Japanese Patent Publication No. 16-16860, Japanese Patent Publication No. 51-32618, Japanese Patent Publication No. 51618)
-38698 etc.) etc. are known.
【０００４】[0004]
【発明が解決しようとする課題】粗テレフタル酸は上記
の如き方法で処理された後、冷却することにより晶析し
た高純度テレフタル酸結晶と母液に分離される。この分
離母液は一部再循環で使用されることはあるが、大部分
は系外へ排出される。接触処理又は水素化還元処理によ
り粗テレフタル酸を精製した場合には４ＣＢＡが安息香
酸又はパラトルイル酸となるので、この母液中には残余
のテレフタル酸と、パラトルイル酸、安息香酸などの有
機物が溶解或いは一部微細な結晶として含まれている。The crude terephthalic acid is treated by the above-mentioned method and then cooled to separate into crystallized high-purity terephthalic acid crystals and a mother liquor. The separated mother liquor may be partially recycled, but most of it is discharged out of the system. When crude terephthalic acid is purified by catalytic treatment or hydroreduction treatment, 4CBA becomes benzoic acid or paratoluic acid, so residual terephthalic acid and organic substances such as paratoluic acid and benzoic acid are dissolved in this mother liquor. It is included as some fine crystals.
【０００５】排出された母液は普通、活性汚泥処理した
後に公有水域へ廃出される。この活性汚泥装置へ送られ
る母液中に溶解或いは一部微細な結晶として含まれてい
る有機物は比較的低い濃度であるが、高純度テレフタル
酸製造装置は通常数万から数十万トン／年の生産規模で
あるため、有機物総量は相当大きくなる。そのため活性
汚泥装置に対する設備投資費用および運転費用がかさむ
ことになり、高純度テレフタル酸製造上、この分離母液
の処理法の改善が強く望まれている。本発明の目的は、
テレフタル酸精製プロセスにおいて排出される分離母液
中の有機物総量を減少し、活性汚泥装置への負荷を低下
させる方法を提供することである。The discharged mother liquor is usually discharged to public water areas after treatment with activated sludge. The organic substances dissolved in the mother liquor sent to this activated sludge unit or contained as some fine crystals have a relatively low concentration, but the high-purity terephthalic acid production unit usually has tens to hundreds of thousands tons / year. Since it is a production scale, the total amount of organic matter is considerably large. Therefore, the facility investment cost and the operating cost for the activated sludge device are increased, and improvement of the treatment method of this separated mother liquor is strongly desired in the production of high-purity terephthalic acid. The purpose of the present invention is to
It is an object of the present invention to provide a method for reducing the total amount of organic substances in a separated mother liquor discharged in a terephthalic acid refining process and reducing the load on an activated sludge device.
【０００６】[0006]
【課題を解決するための手段】発明者は上記の如き課題
を有するテレフタル酸を製造する際に得られる分離母液
の処理方法について鋭意検討した結果、高純度テレフタ
ル酸を晶析させ結晶を分離する際に得られる分離母液を
アルカリ性としてこの分離母液中の有機酸成分を完全に
溶解させた後、酸性とし、濾過などの適当な方法で結晶
を分離・除去することにより、該分離母液中の有機酸成
分を著しく低下させることができることを見出し、本発
明に到達した。Means for Solving the Problems As a result of diligent studies on the method of treating a separation mother liquor obtained when producing terephthalic acid having the above problems, the inventor crystallizes high-purity terephthalic acid to separate crystals. The separated mother liquor obtained at this time is made alkaline to completely dissolve the organic acid component in the separated mother liquor, and then made acidic, and the crystals in the separated mother liquor are separated and removed by an appropriate method such as filtration to separate the organic matter in the separated mother liquor. They have found that the acid component can be remarkably reduced and have reached the present invention.
【０００７】即ち本発明は、高純度テレフタル酸を晶析
させ結晶を分離した分離母液に、アルカリを加えて有機
酸成分を完全に溶解させた後、酸を添加して該母液中の
有機酸成分を沈殿分離することを特徴とする高純度テレ
フタル酸分離母液の処理方法である。That is, according to the present invention, an alkali is added to a separated mother liquor obtained by crystallizing high-purity terephthalic acid to separate crystals, and an organic acid component is completely dissolved in the separated mother liquor. A method for treating a mother liquor for separating high-purity terephthalic acid, which comprises separating the components by precipitation.
【０００８】本発明において該分離母液に予めテレフタ
ル酸を加えた後にアルカリを加えるようにすれば、トル
イル酸などの有機酸成分の沈殿量が更に増大して、テレ
フタル酸精製プロセスにおいて排出される分離母液中の
有機物が減少する。また前述の如く接触処理又は水素化
還元処理により粗テレフタル酸を精製した場合には４Ｃ
ＢＡが安息香酸又はパラトルイル酸となるので、本発明
の方法は粗テレフタル酸を接触処理又は水素化還元処理
により精製して得られた高純度テレフタル酸を処理する
場合に有利に用いられる。以下本発明を詳細に説明す
る。In the present invention, if terephthalic acid is added to the separation mother liquor in advance and then alkali is added, the amount of organic acid components such as toluic acid precipitated further increases, and the separation is discharged in the terephthalic acid refining process. Organic matter in the mother liquor is reduced. When the crude terephthalic acid is purified by the contact treatment or the hydrogenation reduction treatment as described above, it is 4C.
Since BA becomes benzoic acid or paratoluic acid, the method of the present invention is advantageously used for treating high-purity terephthalic acid obtained by purifying crude terephthalic acid by catalytic treatment or hydroreduction treatment. The present invention will be described in detail below.
【０００９】高純度テレフタル酸製造装置から排出され
る分離母液中の有機物成分は、粗テレフタル酸中の不純
物組成、接触処理や水素化還元処理の条件、反応後の晶
析条件および結晶分離温度などによって異なるが、その
概略値は次の通りである。また各々の成分の６０℃にお
ける溶解度を右欄に示す。The organic components in the separation mother liquor discharged from the high-purity terephthalic acid production apparatus include the impurity composition in the crude terephthalic acid, the conditions of contact treatment and hydroreduction treatment, the crystallization conditions after the reaction and the crystal separation temperature. The approximate value is as follows, although it varies depending on the situation. The solubility of each component at 60 ° C is shown in the right column.
【００１０】[0010]
【表１】 分離母液中の有機物組成 （有機物名） （濃度） （６０℃での溶解度） テレフタル酸 ２００〜３０００ｐｐｍ ５０ｐｐｍ パラトルイル酸 １００〜１０００ｐｐｍ １０００ｐｐｍ 安息香酸 ５０〜１０００ｐｐｍ １. １６％ その他 数百ｐｐｍ [Table 1] Organic substance composition in separated mother liquor (Organic substance name) (Concentration) (Solubility at 60 ° C) Terephthalic acid 200 to 3000 ppm 50 ppm Paratoluic acid 100 to 1000 ppm 1000 ppm Benzoic acid 50 to 1000 ppm 1.16% Other hundreds of ppm
【００１１】表１における右欄の溶解度から分かるよう
に、テレフタル酸の６０℃における水に対する溶解度は
非常に小さい。従って分離母液を６０℃まで冷却すれば
テレフタル酸の大部分は結晶となって析出するのでテレ
フタル酸は濾過などの方法で除くことによりができる
が、残りのパラトルイル酸と安息香酸は溶解度が６０℃
でも十分に高いので分離母液を６０℃まで冷却しても除
けないことが分かる。As can be seen from the solubilities in the right column of Table 1, terephthalic acid has a very low solubility in water at 60 ° C. Therefore, if the separated mother liquor is cooled to 60 ° C, most of the terephthalic acid precipitates as crystals, so terephthalic acid can be removed by a method such as filtration, but the remaining paratoluic acid and benzoic acid have a solubility of 60 ° C.
However, since it is sufficiently high, it cannot be removed even if the separated mother liquor is cooled to 60 ° C.
【００１２】本発明において使用される高純度テレフタ
ル酸分離母液はｐ−ジアルキルベンゼン類を液相酸化し
て得られた粗テレフタル酸を精製する際に得られるもの
である。粗テレフタル酸の原料となるｐ−ジアルキルベ
ンゼン類としては通常パラキシレンが使用されるが、置
換基はメチル基に限定する必要はなく、エチル、プロピ
ル、ｉ−プロピル基でも良く、或は、アルデヒド、アセ
チル基の如くカルボキシル基に酸化されるものであれば
良い。また置換基の一つがカルボキシル基であってもよ
い。The high-purity terephthalic acid separation mother liquor used in the present invention is obtained when purifying crude terephthalic acid obtained by liquid-phase oxidation of p-dialkylbenzenes. Para-xylene is usually used as the p-dialkylbenzenes used as a raw material of crude terephthalic acid, but the substituent is not limited to a methyl group, and may be an ethyl, propyl or i-propyl group, or an aldehyde. Any oxidizable group such as an acetyl group can be used as long as it is oxidized to a carboxyl group. Further, one of the substituents may be a carboxyl group.
【００１３】液相酸化は、酢酸あるいは水を含む酢酸を
溶媒としてコバルトおよびマンガン等の重金属及び臭素
化合物を存在させ、温度１５０〜２４０℃、圧力１０〜
３０気圧で空気により行う方法が用いられる。またコバ
ルト触媒存在下、温度１００〜１５０℃、圧力５〜２０
気圧で酸素により酸化反応を行う方法も用いられ、アセ
トアルデヒドやメチルエチルケトン等の促進剤も用いら
れる。The liquid-phase oxidation is carried out by using acetic acid or acetic acid containing water as a solvent in the presence of a heavy metal such as cobalt and manganese and a bromine compound at a temperature of 150 to 240 ° C. and a pressure of 10 to 240 ° C.
A method of using air at 30 atm is used. In the presence of a cobalt catalyst, the temperature is 100 to 150 ° C, the pressure is 5 to 20.
A method of performing an oxidation reaction with oxygen at atmospheric pressure is also used, and an accelerator such as acetaldehyde or methyl ethyl ketone is also used.
【００１４】高純度テレフタル酸はこのような液相酸化
により得られた粗テレフタル酸を精製・晶析することに
より得られる。本発明は接触処理又は水素化還元処理法
により精製した高純度テレフタル酸を晶析して結晶を分
離する際に得られる分離母液の処理する場合に有利に用
いられ、上記の如くこの分離母液には多くの有機酸成分
が含まれている。High-purity terephthalic acid is obtained by purifying and crystallizing crude terephthalic acid obtained by such liquid phase oxidation. INDUSTRIAL APPLICABILITY The present invention is advantageously used in the case of treating a separated mother liquor obtained when crystallizing high-purity terephthalic acid purified by a catalytic treatment or a hydroreduction treatment method and treating the separated mother liquor as described above. Contains many organic acid components.
【００１５】本発明において該分離母液に加えられるア
ルカリとしては、水酸化ナトリウム、水酸化カリウム、
炭酸ソーダ、アンモニア等が用いられる。アルカリ添加
量は該分離母液に含まれる有機酸量により異なり、該分
離母液中の有機酸を全て完全に溶解させるために、該分
離母液中の有機酸総量の化学当量より多いアルカリ添加
量とする必要がある。但し過剰のアルカリ添加は次の酸
析工程での酸添加量が増加することになるので、過剰ア
ルカリ量はできるだけ小さい方が好ましい。In the present invention, the alkali added to the separated mother liquor includes sodium hydroxide, potassium hydroxide,
Sodium carbonate, ammonia, etc. are used. The amount of alkali added varies depending on the amount of organic acid contained in the separated mother liquor, and in order to completely dissolve all the organic acids in the separated mother liquor, the amount of alkali added is larger than the chemical equivalent of the total amount of organic acids in the separated mother liquor. There is a need. However, addition of excess alkali increases the amount of acid added in the subsequent acid precipitation step, so it is preferable that the amount of excess alkali is as small as possible.
【００１６】アルカリ添加により該分離母液中に析出し
ていた有機酸は溶けて均一溶液となり、これに酸を添加
すると、テレフタル酸が酸析によって沈澱する際に、パ
ラトルイル酸や安息香酸の一部も沈澱する（共沈現
象）。この酸析には塩酸や硫酸・などのいわゆる強酸が
用いられる。酸添加量は母液中に含まれている有機酸の
化学当量および過剰に添加したアルカリの化学当量の合
計量に相当する量とすべきであるが、実際の操作ではpH
が 2.5以下となるように添加すれば良い。The organic acid precipitated in the separated mother liquor is dissolved by the addition of alkali to form a homogeneous solution. When an acid is added to this, a part of paratoluic acid or benzoic acid is precipitated when terephthalic acid is precipitated by acid precipitation. Also precipitates (coprecipitation phenomenon). A so-called strong acid such as hydrochloric acid or sulfuric acid is used for this acid precipitation. The amount of acid added should be the amount equivalent to the sum of the chemical equivalents of the organic acids contained in the mother liquor and the chemical equivalents of the alkali added in excess, but in actual operation the pH
Should be added so that the value becomes 2.5 or less.
【００１７】アルカリを添加する際に、あらかじめ分離
母液にテレフタル酸を小量添加しておくと共沈効果は大
きくなり、分離母液から回収されるパラトルイル酸や安
息香酸が増大する。添加するテレフタル酸は高純度であ
る必要は全く無く、実質的にテレフタル酸を含んでおれ
ば良い。不純物を多く含んだテレフタル酸を使っても本
発明の効果に悪影響は生じない。湿分を含んだテレフタ
ル酸のケーキでも良いし、水中や含水酢酸中に懸濁した
テレフタル酸スラリーであっても良く、また既にアルカ
リに溶解、或いは一部溶解した状態のテレフタル酸であ
っても良い。このように実質的にテレフタル酸を含んだ
物質は、商業的な規模での高純度テレフタル酸を生産し
ているプロセスに多少なりとも存在しているケースが多
く、例えば液相酸化工程での洗浄作業で排出されるテレ
フタル酸を含んだ廃液、精製工程での洗浄廃液、或いは
精製工程での運転直後などの極めて限定された状況で生
産される不純物を多く含んだテレフタル酸等を利用する
ことができる。When a small amount of terephthalic acid is added to the separated mother liquor in advance when adding the alkali, the coprecipitation effect becomes large, and the amount of paratoluic acid and benzoic acid recovered from the separated mother liquor increases. The terephthalic acid to be added does not need to have a high purity at all, and may substantially contain terephthalic acid. The use of terephthalic acid containing a large amount of impurities does not adversely affect the effect of the present invention. It may be a cake of terephthalic acid containing moisture, a terephthalic acid slurry suspended in water or water-containing acetic acid, or terephthalic acid already dissolved or partially dissolved in alkali. good. In many cases, substances containing substantially terephthalic acid are often present in the process of producing high-purity terephthalic acid on a commercial scale, such as washing in a liquid phase oxidation step. It is possible to use waste liquid containing terephthalic acid discharged from work, cleaning waste liquid in the refining process, or terephthalic acid containing a large amount of impurities produced in extremely limited situations such as immediately after operation in the refining process. it can.
【００１８】この酸析は低温で処理する程その効果が大
きく、酸の添加および沈殿分離温度は９０℃以下、好ま
しくは６０℃以下である。また添加するテレフタル酸の
量は分離母液中に予め含まれているテレフタル酸の濃度
によって変わって来るが、テレフタル酸添加後の分離母
液中の濃度が０．１％以上になることが好ましい。テレ
フタル酸の添加量がこの水準より多くなることは共沈効
果が増大する結果になるのでかまわないが、当然、使用
するテレフタル酸が多くなる。また実施例から分かるよ
うに、母液中のテレフタル酸濃度と共沈効果の関係は直
線的でなく、テレフタル酸濃度が０．４％以上になって
も共沈効果はあまり増大しない。従って分離母液中のテ
レフタル酸濃度を０．４％以上とすることは経済的観点
から有利とはならない。The effect of this acid precipitation is greater as it is treated at a lower temperature, and the acid addition and precipitation separation temperatures are 90 ° C. or lower, preferably 60 ° C. or lower. Although the amount of terephthalic acid to be added varies depending on the concentration of terephthalic acid previously contained in the separation mother liquor, the concentration in the separation mother liquor after addition of terephthalic acid is preferably 0.1% or more. Increasing the amount of terephthalic acid added above this level may result in an increased coprecipitation effect, but naturally, more terephthalic acid is used. Further, as can be seen from the examples, the relationship between the terephthalic acid concentration in the mother liquor and the coprecipitation effect is not linear, and the coprecipitation effect does not increase significantly even when the terephthalic acid concentration is 0.4% or more. Therefore, it is not advantageous from an economical viewpoint to set the concentration of terephthalic acid in the separated mother liquor to 0.4% or more.
【００１９】本発明の方法により高純度テレフタル酸を
晶析させ、結晶を分離する際に得られる分離母液にアル
カリを加えた後に酸析することによって、該分離母液中
のパラトルイル酸および安息香酸などの有機酸成分が沈
殿するので、沈澱した有機物を濾過などの方法で除け
ば、排出母液中の有機物量を大幅に減少させることがで
き、活性汚泥装置への負担を小さくすることができる。
濾過などの方法で得られた沈殿物は液相酸化装置に戻す
ことにより、該沈殿物中のテレフタル酸が回収されると
共に、パラトルイル酸などは酸化されてテレフタル酸と
なるので、テレフタル酸の収率が向上する。High-purity terephthalic acid is crystallized by the method of the present invention, and an alkali is added to the separated mother liquor obtained when the crystals are separated, followed by acid precipitation to obtain paratoluic acid and benzoic acid in the separated mother liquor. Since the organic acid component of (3) is precipitated, the amount of organic matter in the discharged mother liquor can be significantly reduced by removing the precipitated organic matter by a method such as filtration, and the load on the activated sludge device can be reduced.
By returning the precipitate obtained by a method such as filtration to a liquid phase oxidation device, terephthalic acid in the precipitate is recovered, and paratoluic acid and the like are oxidized to terephthalic acid. The rate is improved.
【００２０】[0020]
【実施例】次に実施例により本発明を更に具体的に説明
する。但し本発明はこれらの実施例により制限されるも
のではない。なお各実施例の各表において用いる記号は
次の通りである。 ＴＡ：テレフタル酸、ｐＴＯＬ：パラトルイル酸、Ｂ
Ａ：安息香酸EXAMPLES Next, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples. The symbols used in each table of each example are as follows. TA: terephthalic acid, pTOL: paratoluic acid, B
A: Benzoic acid
【００２１】実施例１ 粗テレフタル酸を水素化還元処理し、晶析する際に得ら
れた分離母液（テレフタル酸４６０ｐｐｍ、パラトルイ
ル酸８３０ｐｐｍ、安息香酸３２０ｐｐｍ、その他４５
０ｐｐｍ、合計２０６０ｐｐｍ）１ｋｇを三角フラスコ
に取り、温度調節された油浴中に入れて、母液の温度が
６０℃になるように加熱した。このとき三角フラスコに
入れた攪拌子により攪拌した。この母液中には少量の白
色沈殿が見られた。この沈殿物は表１に示された溶解度
から主にテレフタル酸の結晶であることが明らかであ
る。この母液に所定量のテレフタル酸結晶を添加してか
ら２４％の苛性ソーダ水溶液を、ｐＨが１０以上になる
まで少しづつ加え、白色沈殿が完全に溶解して透明な溶
液となったことを確認した。次に６規定濃度の塩酸をＰ
Ｈが２以下になるまで添加したところ、母液には再び白
色沈殿が析出した。このスラリー液を十分に温めたＧ３
フィルターで素早く濾過した。濾液を高速度クロマトグ
ラフィーで分析した結果を表２に示す。Example 1 Separated mother liquor obtained during crystallization of crude terephthalic acid by hydrogenation treatment (460 ppm terephthalic acid, 830 ppm paratoluic acid, 320 ppm benzoic acid, others 45)
1 ppm (0 ppm, total 2060 ppm) was placed in an Erlenmeyer flask, placed in a temperature-controlled oil bath, and heated so that the temperature of the mother liquor was 60 ° C. At this time, the mixture was stirred by a stirrer placed in an Erlenmeyer flask. A small amount of white precipitate was found in this mother liquor. It is clear from the solubilities shown in Table 1 that the precipitate is mainly terephthalic acid crystals. After adding a predetermined amount of terephthalic acid crystals to this mother liquor, a 24% caustic soda aqueous solution was added little by little until the pH became 10 or more, and it was confirmed that the white precipitate was completely dissolved and became a transparent solution. . Next, add 6N hydrochloric acid to P
When H was added to 2 or less, a white precipitate was precipitated again in the mother liquor. G3 which warmed this slurry liquid sufficiently
It was filtered quickly with a filter. The results of analyzing the filtrate by high speed chromatography are shown in Table 2.
【００２２】[0022]
【表２】 母液１kgに対す 濾液中の有機物組成 ｐｐｍるＴＡ投入量 ＴＡ ｐＴＯＬ ＢＡ その他 投入せず ２０ ５２０ ２００ ３９０ ０. ２ｇ ２０ ３３０ ２００ ３８０ １ ｇ ３０ ２５０ １９０ ３８０ ４ ｇ ２０ ６０ ８０ ３５０ ８ ｇ ２０ ５０ ６０ ３５０[Table 2] Organic composition in the filtrate per 1 kg of mother liquor ppm TA input amount TA pTOL BA No other input 20 520 200 390 0.2 g 20 330 330 200 380 1 g 30 250 250 190 380 4 g 20 60 80 80 350 8 g 20 50 60 350
【００２３】実施例２ 実施例１において母液の温度を９０℃に維持しながら、
同様の実験を行った。得られた濾液の分析結果を表３に
示す。Example 2 While maintaining the temperature of the mother liquor at 90 ° C. in Example 1,
Similar experiments were conducted. Table 3 shows the analysis results of the obtained filtrate.
【００２４】[0024]
【表３】 母液１kgに対す 濾液中の有機物組成 ｐｐｍるＴＡ投入量 ＴＡ ｐＴＯＬ ＢＡ その他 投入せず ５０ ５８０ ２３０ ４２０ ０. ２ｇ ４０ ３８０ ２４０ ４３０ １ ｇ ５０ ３００ １９０ ４００ ４ ｇ ４０ １００ １２０ ３８０ ８ ｇ ４０ ８０ １００ ３３０[Table 3] Organic composition in filtrate per 1 kg of mother liquor ppm TA input amount TA pTOL BA No other input 50 580 230 230 420 0.2 g 40 380 240 430 1 g 50 300 300 190 400 4 g 40 100 100 120 380 8 g 40 80 100 330
【００２５】実施例３ 実施例１において母液野温度を３０℃に維持しながら、
同様の実験を行った。得られた濾液の分析結果を表４に
示す。Example 3 While maintaining the mother liquor temperature at 30 ° C. in Example 1,
Similar experiments were conducted. Table 4 shows the analysis results of the obtained filtrate.
【００２６】[0026]
【表４】 母液１kgに対す 濾液中の有機物組成 ｐｐｍるＴＡ投入量 ＴＡ ｐＴＯＬ ＢＡ その他 投入せず ２０ ４００ ２００ ３８０ ０. ２ｇ １０ ２３０ １８０ ３８０ １ ｇ ２０ １２０ １４０ ３７０ ４ ｇ ２０ ３０ ６０ ３３０ ８ ｇ ２０ ３０ ６０ ３３０[Table 4] Organic substance composition in the filtrate per 1 kg of mother liquor TA input amount in ppm TA pTOL BA No other input 20 400 200 380 0.2 g 10 230 180 180 380 1 g 20 120 120 140 370 4 g 20 30 60 30 330 8 g 20 30 60 330
【００２７】比較例１ 所定量のテレフタル酸および２４％苛性ソーダ水溶液を
添加せずに、実施例１と同様の実験を行った。得られた
濾液の分析結果を表５に示す。Comparative Example 1 The same experiment as in Example 1 was conducted without adding the predetermined amounts of terephthalic acid and 24% aqueous sodium hydroxide solution. Table 5 shows the analysis results of the obtained filtrate.
【表５】 母液１kgに対す 濾液中の有機物組成 ｐｐｍるＴＡ投入量 ＴＡ ｐＴＯＬ ＢＡ その他 投入せず ４０ ７８０ ３１０ ４３０[Table 5] Organic matter composition in the filtrate per 1 kg of mother liquor TA input amount in ppm TA pTOL BA No other input 40 780 310 430
【００２８】比較例２ 所定量のテレフタル酸、２４％苛性ソーダ水溶液及び６
規定濃度の塩酸を添加せずに実施例１と同様の実験を行
った。得られた濾液の分析結果を表６に示す。Comparative Example 2 Predetermined amount of terephthalic acid, 24% caustic soda aqueous solution and 6
The same experiment as in Example 1 was conducted without adding the hydrochloric acid of the specified concentration. Table 6 shows the analysis results of the obtained filtrate.
【表６】 母液１kgに対す 濾液中の有機物組成 ｐｐｍるＴＡ投入量 ＴＡ ｐＴＯＬ ＢＡ その他 投入せず ７０ ８００ ３１０ ４３０[Table 6] Organic matter composition in the filtrate per 1 kg of mother liquor TA input amount in ppm TA pTOL BA Others not added 70 800 310 430
【００２９】以上の実施例より次のことが確認される。 （１）一旦アルカリ性にしてから酸析させることによっ
て、濾液中のテレフタル酸は溶解度より低い濃度となる
と共に、パラトルイル酸および安息香酸の濃度も著しく
低下する。 （２）予めテレフタル酸を添加した後に酸析を行うこと
により、濾液中のパラトルイル酸の濃度が更に低下す
る。但しテレフタル酸を一定量以上添加してもその低下
量の変化が小さくなる。 （３）少量のテレフタル酸投入では、濾液中の安息香酸
濃度が変わらないが、投入量を多くするとその濃度が低
下する。 （４）酸析の処理温度が低いほど、濾液中の各有機酸の
濃度が低下する。 （５）アルカリ添加せずに単に酸析のみの場合（比較例
１）ではテレフタル酸濃度が低下するが、パラトルイル
酸および安息香酸の濃度は酸も添加せずに単に濾過のみ
場合（比較例２）と同程度である。From the above embodiments, the following is confirmed. (1) By making the solution alkaline once and acidifying it, the concentration of terephthalic acid in the filtrate becomes lower than the solubility, and the concentrations of paratoluic acid and benzoic acid also significantly decrease. (2) By carrying out acid precipitation after adding terephthalic acid in advance, the concentration of paratoluic acid in the filtrate is further reduced. However, even if a certain amount or more of terephthalic acid is added, the change in the amount of decrease is small. (3) When a small amount of terephthalic acid is added, the concentration of benzoic acid in the filtrate does not change, but when the amount is increased, the concentration decreases. (4) The lower the treatment temperature for acid precipitation, the lower the concentration of each organic acid in the filtrate. (5) The concentration of terephthalic acid decreases when only acid precipitation is performed without adding an alkali (Comparative Example 1), but the concentrations of paratoluic acid and benzoic acid are only when only filtering is performed without adding acid (Comparative Example 2). ) Is about the same.
【００３０】[0030]
【発明の効果】各実施例に示されるように、本発明の方
法により酸析を行うことにより、高純度テレフタル酸を
晶析する際に得られる分離母液中のテレフタル酸、パラ
トイル酸および安息香酸の濃度が著しく低下する。これ
によりテレフタル酸製造装置から排出液中の有機酸濃度
が低下し、活性汚泥装置の負荷が著しく低下する。また
酸析により分離された沈殿物を液相酸化系に投入するこ
とによりテレフタル酸の収率が向上する。[Effects of the Invention] As shown in each example, terephthalic acid, p-toluic acid and benzoic acid in the separated mother liquor obtained when crystallization of high-purity terephthalic acid is carried out by carrying out acid precipitation by the method of the present invention. The concentration of is markedly reduced. As a result, the concentration of the organic acid in the effluent from the terephthalic acid production device decreases, and the load on the activated sludge device decreases significantly. In addition, the yield of terephthalic acid is improved by adding the precipitate separated by acid precipitation to the liquid phase oxidation system.
Claims (3)
した分離母液に、アルカリを加えて有機酸成分を完全に
溶解させた後、酸を添加して該母液中の有機酸成分を沈
殿分離することを特徴とする高純度テレフタル酸分離母
液の処理方法1. An organic acid component is completely dissolved by adding an alkali to a separated mother liquor obtained by crystallizing high-purity terephthalic acid to separate crystals, and then an acid is added to precipitate the organic acid component in the mother liquor. Method for treating mother liquor for separation of high-purity terephthalic acid characterized by separation
した分離母液に、テレフタル酸を加えた後にアルカリを
加える請求項１の高純度テレフタル酸分離母液の処理方
法2. A method of treating a mother liquor for separating high-purity terephthalic acid according to claim 1, wherein alkali is added after adding terephthalic acid to the separated mother liquor in which crystals are separated by crystallizing high-purity terephthalic acid.
接触処理又は水素化還元処理により精製して得られたも
のである請求項１または請求項２の高純度テレフタル酸
分離母液の処理方法3. The method for treating a mother liquor for separating high-purity terephthalic acid according to claim 1 or 2, wherein the high-purity terephthalic acid is obtained by purifying crude terephthalic acid by catalytic treatment or hydroreduction treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16338593A JPH0717902A (en) | 1993-07-01 | 1993-07-01 | Method for treating mother liquid separated from high-purity terephthalic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16338593A JPH0717902A (en) | 1993-07-01 | 1993-07-01 | Method for treating mother liquid separated from high-purity terephthalic acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0717902A true JPH0717902A (en) | 1995-01-20 |
Family
ID=15772889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16338593A Pending JPH0717902A (en) | 1993-07-01 | 1993-07-01 | Method for treating mother liquid separated from high-purity terephthalic acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0717902A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004060525A1 (en) * | 2002-12-27 | 2004-07-22 | Sumitomo Chemical Company, Limited | Method and apparatus for crystallization |
| KR102054643B1 (en) * | 2019-07-16 | 2020-01-22 | 강대권 | Preparation method of benzoic acid from by-products in preparation process of terephthalic acid |
-
1993
- 1993-07-01 JP JP16338593A patent/JPH0717902A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004060525A1 (en) * | 2002-12-27 | 2004-07-22 | Sumitomo Chemical Company, Limited | Method and apparatus for crystallization |
| CN100368047C (en) * | 2002-12-27 | 2008-02-13 | 住友化学株式会社 | Method and apparatus for crystallization |
| US7550042B2 (en) | 2002-12-27 | 2009-06-23 | Sumitomo Chemical Company Limited | Method and apparatus for crystallization |
| KR101108310B1 (en) * | 2002-12-27 | 2012-01-25 | 스미또모 가가꾸 가부시키가이샤 | Method and apparatus for crystallization |
| KR102054643B1 (en) * | 2019-07-16 | 2020-01-22 | 강대권 | Preparation method of benzoic acid from by-products in preparation process of terephthalic acid |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR0152534B1 (en) | Extraction process for removal of impurities from terephthalic acid filtrate | |
| JP5095390B2 (en) | Purification of carboxylic acids by complex formation using selective solvents. | |
| US5705682A (en) | Process for producing highly pure terephthalic acid | |
| EP2292581B1 (en) | Extraction process for removal of impurities from mother liquor in the synthesis of terephthalic acid | |
| NL193538C (en) | Process for preparing terephthalic acid. | |
| JPH0558948A (en) | Preparation of terephthalic acid | |
| EP0265137B1 (en) | Purifying terephthalic acid | |
| JPH1025266A (en) | Production of high-purity isophthalic acid | |
| JPS639498B2 (en) | ||
| JP3421057B2 (en) | Catalyst recovery | |
| KR19980064184A (en) | Production Method of (meth) acrylic Acid | |
| JP2011116792A (en) | Method for producing highly pure aromatic polycarboxylic acid | |
| EP0432910B1 (en) | Process for producing highly pure 2, 6 naphthalene dicarboxylic acid | |
| JP2001226323A (en) | Method for recovering benzyl benzoate | |
| JPH0717902A (en) | Method for treating mother liquid separated from high-purity terephthalic acid | |
| JPS61106535A (en) | Recovery of benzoic acid | |
| JP2924104B2 (en) | Method for producing high-purity isophthalic acid | |
| JP4032186B2 (en) | Method for producing high purity dimethyl 2,6-naphthalenedicarboxylate | |
| CA2295650C (en) | Improved process for separating pure terephthalic acid | |
| JP2899927B2 (en) | Method for producing purified terephthalic acid | |
| JPH07238051A (en) | Production of naphthalene-dicarboxylic acid of high purity | |
| JPH07173100A (en) | Production of high-purity 2,6-naphthalene-dicarboxylic acid | |
| JPH1180074A (en) | Production of highly pure 2,6-naphthalene dicarboxylic acid | |
| JP3028100B2 (en) | Process for producing dimethyl 2,6-naphthalenedicarboxylate | |
| US4317924A (en) | Process for producing purified terephthalic acid |