JP2000026390A - Production of acrylonitrile or methacrylonitrile - Google Patents

Production of acrylonitrile or methacrylonitrile

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Publication number
JP2000026390A
JP2000026390A JP10207087A JP20708798A JP2000026390A JP 2000026390 A JP2000026390 A JP 2000026390A JP 10207087 A JP10207087 A JP 10207087A JP 20708798 A JP20708798 A JP 20708798A JP 2000026390 A JP2000026390 A JP 2000026390A
Authority
JP
Japan
Prior art keywords
reaction gas
cooling
ammonium sulfate
wastewater
water
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
Application number
JP10207087A
Other languages
Japanese (ja)
Inventor
Masaru Someya
賢 染谷
Kazumitsu Sakurai
和光 櫻井
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.)
Asahi Chemical Industry Co Ltd
Original Assignee
Asahi Chemical Industry 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 Asahi Chemical Industry Co Ltd filed Critical Asahi Chemical Industry Co Ltd
Priority to JP10207087A priority Critical patent/JP2000026390A/en
Publication of JP2000026390A publication Critical patent/JP2000026390A/en
Pending legal-status Critical Current

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

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing acrylonitrile or methacrylonitrile, capable of controlling precipitation of ammonium sulfate crystal and rise in viscosity caused by increase in the concentration of a high-boiling organic substance, stably maintaining the amount of circulating cooling water in a reaction gas cooling and cleaning process and reducing the clogging of a drain removing piping from a process. SOLUTION: This method comprises stably and continuously operating a cooling and cleaning process of a reaction gas evolved in an ammoxidation reaction. As for the concentrations of ammonium sulfate, a high-boiling organic substance and water in a circulated cooling water used in the cooling and cleaning process or in a waste water taken out from the process, when the concentration of the high-boiling organic substance is (x) wt.%, that of the ammonium sulfate is (y) wt.% and that of water is (z) wt.%, the operation is carried out in a range shown by x>0, y>0, x+y+z=100, y<=0.0043x2-0.763x+45.574 and y>=1.5714x, preferably x>0, y>0, 0<z<=80, x+y+z=100, y<=0.0043x2-0.763x+45.574 and y>=1.574x.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明はアンモ酸化反応によ
るアクリロニトリルまたはメタクリロニトリルの製造方
法において、その反応ガスの冷却洗浄工程で使用する循
環冷却水中または当該工程より直接抜き出される廃水の
硫酸アンモニウムの結晶析出または高沸点有機物の濃度
増加による粘度上昇を抑えることにより、反応ガス冷却
洗浄工程での循環冷却水量を安定に保ち、且つ反応ガス
冷却洗浄工程からの廃水抜き出し配管の詰まりを少なく
し、それにより反応ガス冷却洗浄工程を安定且つ連続的
に運転する方法に関する。TECHNICAL FIELD The present invention relates to a method for producing acrylonitrile or methacrylonitrile by an ammoxidation reaction, in which crystallization of ammonium sulfate is carried out in circulating cooling water used in a cooling and washing step of the reaction gas or in wastewater directly extracted from the step. By suppressing the increase in viscosity due to precipitation or increase in the concentration of high-boiling organic matter, the amount of circulating cooling water in the reaction gas cooling and washing step is kept stable, and the clogging of the wastewater extraction pipe from the reaction gas cooling and washing step is reduced, thereby The present invention relates to a method for stably and continuously operating a reaction gas cooling and cleaning step.

【０００２】[0002]

【従来の技術】プロパン、プロピレン、イソブチレンま
たはｔ−ブチルアルコールのアンモ酸化反応によりアク
リロニトリルまたはメタクリロニトリルを合成する方法
における反応器出口ガスには、アクリロニトリルまたは
メタクリロニトリル、青酸及びアセトニトリル等の主成
分の他に、未反応アンモニアおよび高沸点有機物が含ま
れている。従ってこの反応ガスよりアクリロニトリルま
たはメタクリロニトリルを回収する過程で、これらの物
質を除去することが必要である。特に重要なことは、未
反応アンモニアを速やかに固定化し高沸点有機物ともに
除去することである。未反応アンモニアの存在は、アク
リロニトリルまたはメタクリロニトリルの回収工程での
ｐＨの上昇の原因となり、結果としてアクリロニトリル
またはメタクリロニトリルの損失につながることは既に
よく知られている。また高沸点有機物は回収工程へ持ち
込まれるとアクリロニトリルまたはメタクリロニトリル
の回収工程熱交換器の汚れや詰まりの原因となり連続運
転の支障となる。2. Description of the Related Art In a method for synthesizing acrylonitrile or methacrylonitrile by an ammoxidation reaction of propane, propylene, isobutylene or t-butyl alcohol, a reactor outlet gas includes acrylonitrile or methacrylonitrile, hydrocyanic acid and acetonitrile. In addition, unreacted ammonia and organic substances having a high boiling point are contained. Therefore, it is necessary to remove these substances in the process of recovering acrylonitrile or methacrylonitrile from this reaction gas. It is particularly important that the unreacted ammonia be quickly fixed to remove high-boiling organic matter. It is already well known that the presence of unreacted ammonia causes an increase in the pH during the recovery of acrylonitrile or methacrylonitrile, resulting in a loss of acrylonitrile or methacrylonitrile. When high-boiling organic matter is brought into the recovery step, the heat exchanger in the recovery step of acrylonitrile or methacrylonitrile becomes dirty or clogged, which hinders continuous operation.

【０００３】そこで従来よりアンモ酸化反応によって得
られるアクリロニトリルまたはメタクリロニトリルの製
造方法としては、反応ガスを反応器を出た後、間接冷却
器で冷やし、次いで冷却洗浄工程へ導き、未反応アンモ
ニアおよび高沸点有機物を適正な量の硫酸等を含む酸水
溶液で洗い固定化して除去するのが一般的である。この
方法に用いられる反応ガス冷却洗浄工程の設備として多
段急冷塔を用いる方法が米国特許第３６４９１７９号明
細書に開示されている。この方法によれば、急冷塔は上
下２段区画（またはそれ以上の多段区画）に分割され、
反応ガスは先ず急冷塔下段区画へ導かれここで硫酸を含
んだ第一冷却水で冷却及び洗浄され反応ガス中の未反応
アンモニアおよび高沸点有機物が分離除去され、次に急
冷塔の上段区画へ導かれ、再度、硫酸を含んだ第二冷却
水で冷却及び未反応アンモニアが分離除去される。そし
て、この第一、第二冷却水は反応ガスと直接接触による
冷却方式で循環使用されている。また該工程で除去した
高沸点有機物および未反応アンモニアの固定化により生
成した硫酸アンモニウムは水とともに下段区画より廃水
として抜き出される。[0003] Conventionally, as a method for producing acrylonitrile or methacrylonitrile obtained by an ammoxidation reaction, a reaction gas is discharged from a reactor, cooled in an indirect cooler, then led to a cooling and washing step, and unreacted ammonia and In general, high-boiling organic substances are removed by washing and fixing with an aqueous acid solution containing an appropriate amount of sulfuric acid or the like. U.S. Pat. No. 3,649,179 discloses a method using a multi-stage quenching tower as equipment for a reaction gas cooling and washing step used in this method. According to this method, the quenching tower is divided into upper and lower two-stage sections (or more multi-stage sections),
The reaction gas is first introduced to the lower section of the quench tower, where it is cooled and washed with the first cooling water containing sulfuric acid to separate and remove unreacted ammonia and high-boiling organic matter in the reaction gas, and then to the upper section of the quench tower. It is led and cooled again by the second cooling water containing sulfuric acid, and unreacted ammonia is separated and removed. The first and second cooling waters are circulated and used in a cooling system by direct contact with the reaction gas. In addition, the ammonium sulfate produced by immobilizing the high-boiling organic matter and unreacted ammonia removed in the step is extracted as wastewater from the lower compartment together with water.

【０００４】反応ガス冷却洗浄工程での反応ガスと水と
の接触が不十分になるとアンモニアおよび高沸点化合物
が後段のアクリロニトリルまたはメタクリロニトリル回
収工程へ持ち込まれるという問題が生じる。従って反応
ガスおよび接触水の偏流を防止し、完全に未反応アンモ
ニア、高沸点有機物および飛散触媒を除去するために
も、安定且つ連続的に冷却水を供給及び循環させ、反応
ガスを水と接触させることが重要である。反応ガス冷却
洗浄工程より抜き出される廃水には多くの硫酸アンモニ
ウムおよび高沸点有機物が含まれており、この廃水を最
終的に処理または廃棄する方法としては焼却処理、湿式
酸化処理または深井戸廃棄法（Ｄｅｅｐｗｅｌｌｉｎ
ｇ）などがある。特に反応ガス冷却洗浄工程から抜き出
される廃水は有機物濃度が高いため、一般的には焼却処
理が採用される場合が多い。また焼却処理を行う前に、
廃水中に含まれる硫酸アンモニウムを晶析後分離回収す
る方法も採用される場合がある。[0004] If the contact between the reaction gas and water in the reaction gas cooling and washing step becomes insufficient, there arises a problem that ammonia and high-boiling compounds are carried into the subsequent acrylonitrile or methacrylonitrile recovery step. Therefore, in order to prevent the drift of the reaction gas and the contact water and completely remove unreacted ammonia, high-boiling organic matter and scattered catalyst, supply and circulate the cooling water stably and continuously to bring the reaction gas into contact with the water. It is important that Waste water extracted from the reaction gas cooling and washing step contains a large amount of ammonium sulfate and high-boiling organic substances. As a method of finally treating or discarding this waste water, incineration treatment, wet oxidation treatment or deep well disposal method ( Deepwellin
g). In particular, wastewater extracted from the reaction gas cooling and washing step has a high organic matter concentration, and thus, in general, incineration is often employed. Before incineration,
A method of separating and recovering ammonium sulfate contained in wastewater after crystallization may be employed.

【０００５】この廃水を焼却処理を行う場合、廃水中に
水が多く含まれると焼却処理時に使用する助燃剤を多く
必要とするため、経済面から考えてできるだけ水の濃度
を低く抑えた廃水を反応ガス冷却洗浄工程から抜き出す
ことが好ましい。しかし反応ガス冷却工程から抜き出さ
れる廃水中の水濃度を低くしすぎると、硫酸アンモニウ
ムおよび高沸点有機物の濃度が高くなり、硫酸アンモニ
ウムの結晶析出、廃水の粘度上昇または配管内での高沸
点有機物の固化などにより反応ガス冷却工程での廃水循
環量の低下を招き、その結果反応ガス冷却洗浄を十分に
実施することができなくなり、連続運転に支障をきたす
という問題があった。また反応ガス冷却洗浄工程より抜
き出した廃水を焼却処理設備へ導く配管内でも、廃水の
温度低下による粘度上昇を原因とする廃水の固化によ
り、安定して冷却洗浄工程より廃水を抜き出すことがで
きなくなるという問題があった。When this wastewater is incinerated, if a large amount of water is contained in the wastewater, a large amount of a flame retardant is required during the incineration treatment. It is preferable to extract from the reaction gas cooling and washing step. However, if the water concentration in the wastewater extracted from the reaction gas cooling step is too low, the concentration of ammonium sulfate and high-boiling organic matter will increase, causing ammonium sulfate to crystallize, increasing the viscosity of the wastewater, or solidifying high-boiling organic matter in the piping. For example, the amount of circulating wastewater in the reaction gas cooling step is reduced, and as a result, the reaction gas cooling and cleaning cannot be performed sufficiently, which hinders continuous operation. In addition, even in the pipe that leads the wastewater extracted from the reaction gas cooling and cleaning process to the incineration treatment equipment, the wastewater cannot be stably extracted from the cooling and cleaning process due to the solidification of the wastewater due to the viscosity increase due to the temperature decrease of the wastewater. There was a problem.

【０００６】この反応ガス冷却洗浄工程より抜き出す廃
水中の硫酸アンモニウムおよび高沸点有機物の濃度につ
いては、特公昭４４−１５６４５号公報や特公昭４９−
２５５６０号公報で反応ガス冷却洗浄設備より抜き出す
廃水の高沸点有機物濃度について提案されているが、こ
の場合廃水中の硫酸アンモニウム濃度についての記載は
存在していない。実際に硫酸アンモニウムも含んだ廃水
の高沸点有機物濃度が特公昭４４−１５６４５号公報や
特公昭４９−２５５６０号公報記載の範囲となるよう
に、反応器の運転条件および反応ガス冷却洗浄工程の運
転条件を操作したところ、硫酸アンモニウムの濃度が増
加した場合、硫酸アンモニウムの結晶が析出しはじめ、
その結果反応ガス冷却洗浄工程からの抜き出し廃水配管
の詰まりが生じた。The concentrations of ammonium sulfate and high-boiling organic matter in the wastewater extracted from the reaction gas cooling and washing step are described in JP-B-44-15645 and JP-B-49-45.
No. 25560 proposes a high-boiling-point organic matter concentration of wastewater extracted from a reaction gas cooling and washing facility, but in this case, there is no description of an ammonium sulfate concentration in the wastewater. The operating conditions of the reactor and the operating conditions of the reaction gas cooling and washing step are such that the high-boiling organic matter concentration of the wastewater containing ammonium sulfate actually falls within the range described in JP-B-44-15645 and JP-B-49-25560. As a result, when the concentration of ammonium sulfate increased, ammonium sulfate crystals began to precipitate,
As a result, clogging of the wastewater pipe drawn from the reaction gas cooling and washing step occurred.

【０００７】また、米国特許第３６４９１７９号明細書
では多段急冷塔の第一冷却水中の硫酸アンモニウムの濃
度について提案されている。しかしこの場合、同時に含
まれる高沸点有機物濃度については何も提案されていな
い。実際に反応ガス冷却洗浄工程から抜き出される廃水
中の硫酸アンモニウム濃度が米国特許第３６４９１７９
号明細書記載の範囲となるように、反応器の運転条件お
よび反応ガス冷却洗浄工程の運転条件を操作したとこ
ろ、高沸点有機物濃度が増加した場合、廃水の粘度上昇
が起こり、その結果反応ガス冷却洗浄工程における循環
冷却水の流量の低下が起こった。即ち、硫酸アンモニウ
ムと高沸点有機物が混在する廃水の硫酸アンモニウム結
晶の析出や高沸点化合物による粘度上昇を防ぐために
は、個々の濃度範囲を管理するのではなく、硫酸アンモ
ニウム、高沸点化合物および水の各濃度の関係をある範
囲内に維持することが大切であるが、その範囲に関して
は明確にはなっていない。Also, US Pat. No. 3,649,179 proposes a concentration of ammonium sulfate in the first cooling water of the multistage quenching tower. However, in this case, nothing has been proposed for the concentration of the high-boiling organic matter contained at the same time. The concentration of ammonium sulfate in the wastewater actually extracted from the reaction gas cooling and washing step is as described in US Pat. No. 3,649,179.
When the operating conditions of the reactor and the operating conditions of the reaction gas cooling and washing step were operated so as to fall within the range described in the specification, when the concentration of high boiling organic substances increased, the viscosity of the wastewater increased, and as a result, the reaction gas The flow rate of the circulating cooling water in the cooling and washing process was reduced. That is, in order to prevent precipitation of ammonium sulfate crystals and increase in viscosity due to high-boiling compounds in wastewater in which ammonium sulfate and high-boiling organic substances are mixed, rather than controlling individual concentration ranges, each concentration of ammonium sulfate, high-boiling compounds and water is controlled. It is important to keep the relationship within a certain range, but the scope is not clear.

【０００８】[0008]

【発明が解決しようとする課題】本発明はアンモ酸化反
応によるアクリロニトリルまたはメタクリロニトリルの
製造方法において、その反応ガスの冷却洗浄工程で使用
する循環冷却水または該工程から直接抜き出される廃水
の硫酸アンモニウムの結晶析出または高沸点有機物の濃
度増加による粘度上昇を抑えることで、反応ガス冷却洗
浄工程での循環洗浄液量を安定に保ち、且つ反応ガス冷
却洗浄工程からの廃水抜き出し配管の詰まりを少なく
し、反応ガス冷却洗浄工程を安定且つ連続的に運転する
方法に関する。SUMMARY OF THE INVENTION The present invention relates to a process for producing acrylonitrile or methacrylonitrile by an ammoxidation reaction, wherein ammonium sulphate is used for circulating cooling water used in a cooling and washing step of the reaction gas or waste water directly extracted from the step. By suppressing the increase in viscosity due to the precipitation of crystals or the increase in the concentration of organic substances having a high boiling point, the amount of circulating cleaning liquid in the reaction gas cooling and cleaning step is kept stable, and the clogging of the wastewater discharge pipe from the reaction gas cooling and cleaning step is reduced, The present invention relates to a method for stably and continuously operating a reaction gas cooling and cleaning step.

【０００９】[0009]

【課題を解決するための手段】本発明者らは、前記課題
を解決するため鋭意研究を重ねた結果、アンモ酸化反応
によるアクリロニトリルまたはメタクリロニトリルの製
造方法において、その反応ガスの冷却洗浄工程で使用す
る循環冷却水中または該工程から直接抜き出される廃水
中の硫酸アンモニウム、高沸点有機物および水の各濃度
をある特定の濃度範囲とすることによって硫酸アンモニ
ウムの結晶析出または高沸点有機物の濃度増加による粘
度上昇を抑え、その結果反応ガス冷却洗浄工程での循環
冷却水量を安定に保ち、且つ反応ガス冷却洗浄工程から
の廃水抜き出し配管の詰まりを少なくし得ることを見出
し本発明を完成させた。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, in a method for producing acrylonitrile or methacrylonitrile by an ammoxidation reaction, the reaction gas is cooled and washed in a cooling step. By increasing the respective concentrations of ammonium sulfate, high-boiling organic substances and water in the circulating cooling water to be used or the wastewater extracted directly from the process to a specific concentration range, the viscosity increases due to precipitation of ammonium sulfate crystals or an increase in the concentration of high-boiling organic substances. The present invention has been found that the amount of circulating cooling water in the reaction gas cooling and washing step can be kept stable, and that the clogging of the wastewater discharge pipe from the reaction gas cooling and washing step can be reduced.

【００１０】すなわち本発明は、反応ガス冷却洗浄工程
から排出される廃水中の高沸点有機物の重量に対する硫
酸アンモニウムの重量が１．５７１４以上であるアンモ
酸化反応によるアクリロニトリルまたはメタクリロニト
リルの製造方法において、その反応ガスの冷却洗浄工程
で使用する循環冷却水中または該工程から抜き出される
廃水中の硫酸アンモニウム、高沸点有機物および水の濃
度を高沸点有機物をｘ重量％、硫酸アンモニウムをｙ重
量％および水をｚ重量％とした場合、ｘ＞０、ｙ＞０、
ｘ＋ｙ＋ｚ＝１００、ｙ≦０．００４３ｘ2 −０．７６
３ｘ＋４５．５７４、およびｙ≧１．５７１４ｘで示さ
れる範囲、好ましくはｘ＞０、ｙ＞０、０＜ｚ≦８０、
ｘ＋ｙ＋ｚ＝１００、ｙ≦０．００４３ｘ2 −０．７６
３ｘ＋４５．５７４，およびｙ≧１．５７１４ｘで示さ
れる範囲で運転することを特徴とするアクリロニトリル
またはメタクリロニトリルの製造方法である。That is, the present invention relates to a method for producing acrylonitrile or methacrylonitrile by an ammoxidation reaction in which the weight of ammonium sulfate is at least 1.5714 based on the weight of high-boiling organic matter in the wastewater discharged from the reaction gas cooling and washing step. The concentrations of ammonium sulfate, high-boiling organic substances and water in the circulating cooling water used in the cooling and washing step of the reaction gas or in the wastewater extracted from the step are x weight% of high boiling organic substances, y weight% of ammonium sulfate and z of water. Weight%, x> 0, y> 0,
x + y + z = 100, y ≦ 0.0043x 2 −0.76
3x + 45.574, and the range indicated by y ≧ 1.5714x, preferably x> 0, y> 0, 0 <z ≦ 80,
x + y + z = 100, y ≦ 0.0043x 2 −0.76
A process for producing acrylonitrile or methacrylonitrile, characterized by operating in a range indicated by 3x + 45.574 and y ≧ 1.5714x.

【００１１】なお、ここで述べる高沸点有機物とは、後
に示す高沸点有機物濃度測定方法で測量される物質であ
り、例えば、アクリロニトリルまたはメタクリロニトリ
ルよりも沸点の高い酢酸、アクリル酸、フマロニトリ
ル、スクシノニトリル等の物質の他、アクリロニトリル
またはメタクリロニトリルの反応・重合物やタール状の
物質も含まれる。。以下に、本発明の内容について詳し
く述べる。プロピレンまたはプロパンのアンモ酸化によ
りアクリロニトリルを製造する場合、またはイソブチレ
ンまたはｔ−ブチルアルコールのアンモ酸化によりメタ
クリロニトリルを製造する場合、目的成分のアクリロニ
トリルまたはメタクリロニトリルの収量を高めるため、
副反応で生成するアクロレインまたはメタクロレインの
生成量を少なくしなければならない。そのためにはプロ
パンまたはプロピレンに対するアンモニアのモル比、ま
たはイソブチレンまたはｔ−ブチルアルコールに対する
アンモニアのモル比を化学量論比より大きな値で反応さ
せる必要がある。その結果、反応器出口ガス中には必ず
未反応アンモニアが残っているのが一般的である。The high-boiling organic substance described herein is a substance measured by a high-boiling-point organic substance concentration measuring method described later, and is, for example, acetic acid, acrylic acid, fumaronitrile, or succinic acid having a higher boiling point than acrylonitrile or methacrylonitrile. In addition to substances such as synonitrile, reaction / polymerized products of acrylonitrile or methacrylonitrile and tar-like substances are also included. . Hereinafter, the contents of the present invention will be described in detail. When producing acrylonitrile by ammoxidation of propylene or propane, or when producing methacrylonitrile by ammoxidation of isobutylene or t-butyl alcohol, to increase the yield of acrylonitrile or methacrylonitrile of the target component,
The amount of acrolein or methacrolein generated by side reactions must be reduced. For that purpose, the molar ratio of ammonia to propane or propylene, or the molar ratio of ammonia to isobutylene or t-butyl alcohol needs to be reacted at a value larger than the stoichiometric ratio. As a result, generally, unreacted ammonia always remains in the reactor outlet gas.

【００１２】勿論、未反応アンモニア以外に反応器出口
ガス中にはアクリロニトリルまたはメタクリロニトリ
ル、青酸およびアセトニトリル等の主成分の他に、高沸
点有機物および反応器からの飛散触媒等も含まれてい
る。目的とするアクリロニトリルまたはメタクリロニト
リルの収量を上げるためには、未反応アンモニアを速や
かに固定化し除去することが重要であり、そのために反
応器出口ガスを冷却することおよび未反応アンモニアを
固定化除去するために、反応ガス冷却洗浄工程が設けら
れ、適正な量の酸を含む水溶液を循環し反応ガスが冷却
洗浄されている。この反応ガス冷却洗浄工程で反応ガス
に含まれる高沸点有機物および反応器からの飛散触媒も
同時に循環冷却液で洗浄される。反応ガス中の未反応ア
ンモニアを酸で固定化し、且つ高沸点有機物および飛散
触媒を反応ガスから除いた時に発生する、未反応アンモ
ニアと酸の反応物、高沸点有機物および飛散触媒を含む
水溶液は、再び反応ガス冷却洗浄工程の循環冷却水とし
て使用され、この水溶液の中に新たな未反応アンモニア
固定用の酸および／または新たな供給水を添加後、反応
ガス冷却洗浄工程で再使用される。しかし、この水溶液
を循環使用していると、この水溶液中の未反応アンモニ
アと酸の反応物、高沸点有機物および飛散触媒の濃度が
増加する。そこで、これらの濃度を一定に保つため、新
たな未反応アンモニア固定用の酸および／または新たな
供給水を添加する前の循環冷却水の一部は、反応ガス冷
却洗浄工程からの廃水として系外へ抜き出される。Of course, in addition to unreacted ammonia, the reactor outlet gas contains, in addition to the main components such as acrylonitrile or methacrylonitrile, hydrocyanic acid and acetonitrile, also high-boiling organic substances and catalysts scattered from the reactor. . In order to increase the yield of the target acrylonitrile or methacrylonitrile, it is important to immobilize and remove unreacted ammonia promptly.To this end, it is necessary to cool the reactor outlet gas and fix and remove unreacted ammonia. For this purpose, a reaction gas cooling and washing step is provided, and the reaction gas is cooled and washed by circulating an aqueous solution containing an appropriate amount of acid. In this reaction gas cooling and washing step, the high boiling organic matter contained in the reaction gas and the catalyst scattered from the reactor are simultaneously washed with the circulating cooling liquid. An aqueous solution containing unreacted ammonia and an acid, a reactant of unreacted ammonia and an acid, a high-boiling organic substance and a scattering catalyst, which is generated when the unreacted ammonia in the reaction gas is fixed with an acid and the high-boiling organic substance and the scattering catalyst are removed from the reaction gas, It is used again as circulating cooling water in the reaction gas cooling and washing step, and after adding a new acid for fixing unreacted ammonia and / or new supply water to this aqueous solution, it is reused in the reaction gas cooling and washing step. However, when this aqueous solution is circulated, the concentrations of reactants of unreacted ammonia and acid, high-boiling organic substances, and flying catalyst in this aqueous solution increase. Therefore, in order to keep these concentrations constant, part of the circulating cooling water before adding new unreacted ammonia fixing acid and / or new supply water is used as wastewater from the reaction gas cooling and washing step. It is pulled out.

【００１３】未反応アンモニアを固定化するために用い
られる酸としては単独でも二種類以上の酸を混合して用
いても良いが、一般的には有価な硫酸アンモニウムとし
て回収する為や後処理の容易さから硫酸が用いられる。
従って、反応ガス冷却洗浄工程で使用される循環冷却水
中または該工程から抜き出される廃水中には高沸点化合
物、水の他に未反応アンモニアの固定化により生成した
硫酸アンモニウム等が含まれる。この工程について図１
を用いて更に詳細に説明するが、本発明がこれらにより
何ら限定されるものではない。反応器からの反応ガスは
導管１により急冷塔２へ導かれる。この急冷塔２では上
部より酸を含んだ冷却洗浄用の水が分散され、反応ガス
と水が接触することで反応ガスの冷却洗浄が行われる。
冷却洗浄後の水は急冷塔２の底部より抜き出され導管３
を通して循環使用され、この水中には急冷塔２で反応ガ
スより除去した高沸点有機物および未反応アンモニアの
固定化により生成した硫酸アンモニウムが含まれる。未
反応アンモニア固定用の硫酸の供給は導管５より行われ
る。また冷却洗浄後の反応ガスは導管６を通して後段の
反応ガス冷却洗浄設備またはアクリロニトリルまたはメ
タクリロニトリル回収工程へ運ばれる。反応ガス冷却洗
浄後に発生する廃水は、導管３内の冷却洗浄用水の一部
を導管７を通して系外へ廃水として抜き出される。急冷
塔へ冷却洗浄用水を供給する場合は、導管８を通して行
われる。The acid used for immobilizing the unreacted ammonia may be used alone or as a mixture of two or more kinds of acids. However, it is generally used for recovering as valuable ammonium sulfate and easy for post-treatment. So sulfuric acid is used.
Accordingly, the circulating cooling water used in the reaction gas cooling and washing step or the wastewater extracted from the step contains high boiling compounds, water, and ammonium sulfate generated by immobilizing unreacted ammonia, in addition to water. This process is shown in FIG.
Will be described in more detail, but the present invention is not limited thereto. The reaction gas from the reactor is led to a quench tower 2 by a conduit 1. In the quenching tower 2, water for cooling and washing containing acid is dispersed from the upper portion, and the reaction gas and water come into contact with each other to cool and wash the reaction gas.
The water after cooling and washing is extracted from the bottom of the quenching tower 2 and the pipe 3
The water contains high-boiling organic matter removed from the reaction gas in the quenching tower 2 and ammonium sulfate generated by immobilization of unreacted ammonia. Sulfuric acid for fixing unreacted ammonia is supplied from a conduit 5. The reaction gas after the cooling and washing is transported through a conduit 6 to a subsequent reaction gas cooling and washing facility or an acrylonitrile or methacrylonitrile recovery step. The wastewater generated after the reaction gas cooling and washing is withdrawn as a wastewater by draining a part of the cooling and washing water in the conduit 3 through the conduit 7 to the outside of the system. When cooling water is supplied to the quenching tower, the cooling water is supplied through the conduit 8.

【００１４】本発明で使用する反応ガス冷却洗浄工程
は、反応ガスと循環冷却水が直接接触できる図１のよう
な設備であれば良く、必要に応じて２区画以上に分割す
ることもできる。また当該急冷塔内部には、反応ガスと
循環冷却水の接触を良くするために充填層を設けたり、
液分散用のスプレーノズルを設けても良い。また急冷塔
の運転操作条件は、急冷塔の構造または後工程への高沸
点有機物および未反応アンモニアの持ち込み量により運
転操作が決定される。本発明で使用する硫酸の供給量の
調整は、硫酸を一定量供給しながら反応器運転条件を変
更させ未反応アンモニア量を調整する方法、急冷塔冷却
洗浄循環水のｐＨを見ながら供給硫酸量を調整する方
法、または導管６を通して送られたアクリロニトリルま
たはメタクリロニトリル回収工程でのｐＨを見ながら供
給硫酸量を調整する等を採用しても良い。The reaction gas cooling and washing step used in the present invention may be any equipment as shown in FIG. 1 which can directly contact the reaction gas and the circulating cooling water, and may be divided into two or more sections as necessary. Also, inside the quenching tower, a packed bed is provided to improve the contact between the reaction gas and the circulating cooling water,
A spray nozzle for liquid dispersion may be provided. The operating condition of the quenching tower is determined by the structure of the quenching tower or the amount of high-boiling organic matter and unreacted ammonia brought into the subsequent process. The supply amount of sulfuric acid used in the present invention is adjusted by changing the reactor operating conditions while supplying a fixed amount of sulfuric acid to adjust the amount of unreacted ammonia, and by controlling the amount of sulfuric acid supplied while checking the pH of the cooling water for cooling and cooling the quench tower. May be adjusted, or the amount of sulfuric acid supplied may be adjusted while monitoring the pH in the acrylonitrile or methacrylonitrile recovery step sent through the conduit 6.

【００１５】本発明における反応ガス冷却洗浄工程で使
用する循環冷却水中および該工程より抜き出す廃水中の
高沸点有機物、硫酸アンモニウムおよび水の重量濃度は
次に示す方法で求める。反応ガス冷却洗浄工程より抜き
出した廃水を蒸発皿に直接採取し、この採取した液を沸
騰浴で水分を蒸発させた後１０５℃で１時間乾燥させ、
デシケーター内で放冷する。残存物を４０℃の温水に溶
解し、ホルムアルデヒド法により残存物中の硫酸アンモ
ニウムの量を測定する。ホルムアルデヒド法は硫酸アン
モニウムにホルムアルデヒドを加えて、生成した硫酸を
アルカリ滴定することにより硫酸アンモニウム量を測定
する方法である。下記式に採取したサンプル量Ｓｇ、残
存物量Ｔｇ（乾燥後の高沸点有機物と硫酸アンモニウム
の合計量）および測定された硫酸アンモニウムの量Ｕｇ
をあてはめ、それぞれの量から高沸点有機物、硫酸アン
モニウムおよび水の濃度を算出する。The weight concentrations of high-boiling organic matter, ammonium sulfate and water in the circulating cooling water used in the reaction gas cooling and washing step and the wastewater extracted from the step are determined by the following method. The wastewater extracted from the reaction gas cooling and washing step is directly collected in an evaporating dish, and the collected liquid is evaporated in a boiling bath and then dried at 105 ° C. for 1 hour.
Allow to cool in the desiccator. The residue is dissolved in warm water at 40 ° C., and the amount of ammonium sulfate in the residue is measured by the formaldehyde method. The formaldehyde method is a method in which formaldehyde is added to ammonium sulfate, and the amount of ammonium sulfate is measured by alkali titration of the generated sulfuric acid. The amount of sample Sg, the amount of residual matter Tg (total amount of high-boiling organic matter and ammonium sulfate after drying) and the amount of measured ammonium sulfate Ug
And the concentrations of the high-boiling organic matter, ammonium sulfate and water are calculated from the respective amounts.

【００１６】 ｘ（重量％）＝〔（Ｔ−Ｕ）／Ｓ〕×１００ ｙ（重量％）＝（Ｕ／Ｓ）×１００ ｚ（重量％）＝〔（Ｓ−Ｔ）／Ｓ〕×１００ ｘ：高沸点有機物の重量濃度（重量％） ｙ：硫酸アンモニウムの重量濃度（重量％） ｚ：水の重量濃度（重量％） なお、該廃水中には反応器からの飛散触媒が微量含まれ
ているが、上記分析方法により、該触媒濃度は高沸点有
機物の重量濃度に含まれる。X (% by weight) = [(TU) / S] × 100 y (% by weight) = (U / S) × 100 z (% by weight) = [(ST) / S] × 100 x: weight concentration of high boiling organic matter (% by weight) y: weight concentration of ammonium sulfate (% by weight) z: weight concentration of water (% by weight) The wastewater contains a small amount of catalyst scattered from the reactor. However, according to the above analysis method, the catalyst concentration is included in the weight concentration of the high-boiling organic matter.

【００１７】本発明における反応ガス冷却洗浄工程で使
用する循環冷却水または該工程より抜き出す廃水中の高
沸点有機物重量濃度（ｘ重量％）、硫酸アンモニウム重
量濃度（ｙ重量％）および水の重量濃度（ｚ重量％）範
囲は、ｘ＞０、ｙ＞０、ｘ＋ｙ＋ｚ＝１００、ｙ≦０．
００４３ｘ2 −０．７６３ｘ＋４５．５７４、およびｙ
≧１．５７１４ｘで示される範囲である。この各濃度の
関係を図で示すと図２の斜線で示された部分の濃度範囲
である。更に該廃水を焼却処理する場合経済性を考慮
し、好ましくはｘ＞０、ｙ＞０，０＜ｚ≦８０、ｘ＋ｙ
＋ｚ＝１００、ｙ≦０．００４３ｘ2 −０．７６３ｘ＋
４５．５７４、およびｙ≧１．５７１４ｘで示される範
囲である。この各濃度の関係を図で示すと図３の斜線で
示された部分の濃度範囲である。The weight concentration of high-boiling organic matter (x% by weight), the weight concentration of ammonium sulfate (y% by weight) and the weight concentration of water in the circulating cooling water used in the reaction gas cooling and washing step or the wastewater extracted from the step are as follows. z% by weight) range is x> 0, y> 0, x + y + z = 100, y ≦ 0.
0043x 2 -0.763x + 45.574, and y
≧ 1.5714x. The relationship between these densities is shown in the figure, which is the density range of the shaded portion in FIG. Further, when the wastewater is incinerated, it is preferable to consider x> 0, y> 0, 0 <z ≦ 80, x + y
+ Z = 100, y ≦ 0.0043x 2 −0.763x +
45.574, and y ≧ 1.5714x. The relationship between the respective densities is shown in the drawing, which is the density range of the hatched portion in FIG.

【００１８】本発明における反応ガス冷却洗浄工程での
循環冷却水中または該工程から抜き出される廃水中の高
沸点有機物および硫酸アンモニウムの濃度の制御方法に
ついては、反応器の運転条件を変更し反応ガスに含まれ
る未反応アンモニアまたは高沸点有機物の量を制御する
方法、反応ガス冷却洗浄工程の運転圧力を変更し水の蒸
発量を制御する方法、該工程での導管５を通して注入す
る硫酸の量を制御する方法、洗浄冷却水より導管７を通
して抜き出す廃水の量を制御する方法、導管８を通して
反応ガス冷却洗浄工程へ供給する水の量を制御する方法
のうち少なくとも１つ以上の制御方法を採用することに
より行われる。また反応ガス冷却洗浄工程へ供給する水
については、アンモ酸化反応で生成する水の凝縮分でも
良く、アクリロニロリルまたはメタクリロニトリルの回
収精製工程で排出される廃水および／または有機物を含
む水溶液の一部または全部を再利用しても良い。また多
段急冷塔を反応ガス冷却洗浄工程に使用する場合、上区
画段の高沸点有機物および硫酸アンモニウムの濃度が比
較的低い循環冷却水の一部を導き、反応ガス冷却洗浄工
程から抜き出される廃水中の高沸点有機物および硫酸ア
ンモニウムの濃度を調整しても良い。In the method of controlling the concentration of high-boiling organic matter and ammonium sulfate in the circulating cooling water in the reaction gas cooling washing step or the wastewater extracted from the step in the present invention, the operating conditions of the reactor are changed to change the reaction gas. A method for controlling the amount of unreacted ammonia or high-boiling organic matter contained, a method for controlling the amount of water evaporated by changing the operating pressure in the reaction gas cooling and washing step, and a method for controlling the amount of sulfuric acid injected through the conduit 5 in the step. And at least one of a method of controlling the amount of wastewater withdrawn from the cleaning cooling water through the conduit 7 and a method of controlling the amount of water supplied to the reaction gas cooling and cleaning step through the conduit 8. It is performed by The water supplied to the reaction gas cooling and washing step may be a condensate of water generated in the ammoxidation reaction, and may be a part of an aqueous solution containing wastewater and / or organic substances discharged in the step of recovering and refining acryloniloryl or methacrylonitrile. Or you may reuse all. When a multi-stage quenching tower is used for the reaction gas cooling and washing step, part of the circulating cooling water having a relatively low concentration of high-boiling organic matter and ammonium sulfate in the upper section is led to wastewater extracted from the reaction gas cooling and washing step. The concentration of the high-boiling organic compound and ammonium sulfate may be adjusted.

【００１９】本発明における反応ガス冷却洗浄工程での
循環冷却水中または該工程から抜き出される廃水中の高
沸点有機物および硫酸アンモニウムの濃度を管理するに
あたり、簡便な管理方法の一つとして当該工程の循環冷
却水または該工程から抜き出される廃水の比重を測定し
運転管理することが有効な方法である。特に硫酸アンモ
ニウムまたは高沸点有機物どちらか一方の濃度がほぼ一
定の場合は、特に有効な方法である。In controlling the concentrations of high-boiling organic matter and ammonium sulfate in the circulating cooling water in the reaction gas cooling and washing step in the present invention or the wastewater extracted from the step, the circulation of the step is one of the simple control methods. It is an effective method to measure the specific gravity of the cooling water or the wastewater extracted from the process and control the operation. This is a particularly effective method particularly when the concentration of either ammonium sulfate or a high-boiling organic substance is almost constant.

【００２０】[0020]

【実施例】以下に実施例を挙げて本発明を詳細に説明す
る。The present invention will be described in detail below with reference to examples.

【実施例１】反応ガス冷却洗浄工程が２区画からなり、
第一洗浄冷却部が図１に示すような構造である直径が
９．７ｍの２段急冷塔を用いて実施した。第一急冷部上
部にはホロコーンタイプのスプレーノズルが急冷塔第一
洗浄冷却部の断面積に対して２．３個／ｍ2 の密度で設
置されており、充填物等の設置は無く、約１５０Ｔ／Ｈ
の洗浄冷却水が導管３を通して第一急冷部全断面にまん
べんなく散布されている。洗浄冷却水にはｐＨが５．５
になるように導管５より硫酸が注入され、この洗浄冷却
水の一部を廃水として導管７より抜き出した。また洗浄
冷却水中の高沸点有機物および硫酸アンモニウムの濃度
の調整方法としては、反応器の運転条件を変更し反応ガ
スに含まれる未反応アンモニアの量を調整する方法、洗
浄冷却水より導管７を通して抜き出す廃水の量を調整す
る方法および第一急冷部の後部に備えている第二急冷部
冷却洗浄循環水の一部を導管８を通して注入する方法に
より行った。この方法で抜き出す廃水の高沸点有機物が
１０ｗｔ％および硫酸アンモニウムの濃度が３１ｗｔ％
となるように運転を行ったところ、約６ヶ月の運転を継
続したが、導管３での洗浄冷却水の循環量の低下も認め
られず、安定した運転が継続できた。また廃水抜き出し
導管７の詰まりも認められず、安定して廃水を抜き出す
ことができた。この運転により、反応ガス冷却洗浄工程
を長期間安定且つ連続的に運転することができた。な
お、このときの廃水を採取し高沸点有機物および硫酸ア
ンモニウムの濃度を測定したところ、それぞれ９．７ｗ
ｔ％および３０．２ｗｔ％であった。Embodiment 1 The reaction gas cooling and cleaning step comprises two sections,
The test was performed using a two-stage quenching tower having a diameter of 9.7 m, in which the first washing and cooling unit had a structure as shown in FIG. At the top of the first quenching section, a hollow cone type spray nozzle is installed at a density of 2.3 pieces / m 2 with respect to the cross-sectional area of the quenching tower first washing and cooling section. About 150T / H
Of washing cooling water is evenly sprayed through the conduit 3 over the entire cross section of the first quenching section. PH 5.5 for washing cooling water
Sulfuric acid was injected from the conduit 5 so as to obtain a part of the washing and cooling water, and a part of the water was extracted from the conduit 7 as wastewater. The method for adjusting the concentration of high-boiling organic matter and ammonium sulfate in the washing cooling water includes changing the operating conditions of the reactor to adjust the amount of unreacted ammonia contained in the reaction gas, and the wastewater extracted from the washing cooling water through the conduit 7. And the method of injecting a part of the cooling and circulating water of the second quenching part cooling and washing provided in the rear part of the first quenching part through the conduit 8. High-boiling-point organic matter of wastewater extracted by this method is 10 wt% and the concentration of ammonium sulfate is 31 wt%.
As a result, the operation was continued for about 6 months. However, a decrease in the circulation amount of the washing cooling water in the conduit 3 was not observed, and stable operation was continued. In addition, no clogging of the wastewater discharge conduit 7 was recognized, and the wastewater could be discharged stably. By this operation, the reaction gas cooling and cleaning step could be operated stably and continuously for a long period of time. The wastewater at this time was sampled, and the concentrations of high-boiling organic matter and ammonium sulfate were measured.
t% and 30.2 wt%.

【００２１】また、上記の運転で得られた導管７の廃水
を１リットルのビーカーに採り、温浴中に浸し、廃水温
度を８５℃に保った状態で、該廃水の粘度を測定したと
ころ、１１ｃｐであった。また廃水を室温まで下げ２６
℃となったところで再び該廃水の粘度を測定したところ
２３ｃｐであった。この結果、この廃水の高沸点有機物
および硫酸アンモニウムの濃度では、粘度上昇は認めら
れなかった。なお粘度の測定には、（株）東京計器製Ｃ
形粘度計を用いて行った。Further, the wastewater in the conduit 7 obtained by the above operation was taken in a 1-liter beaker, immersed in a warm bath, and the viscosity of the wastewater was measured while maintaining the wastewater temperature at 85 ° C. Met. Also reduce the wastewater to room temperature 26
The temperature of the wastewater was measured again when the temperature reached ° C, and it was 23 cp. As a result, no increase in viscosity was observed at the concentration of high-boiling organic matter and ammonium sulfate in the wastewater. Note that the viscosity was measured using C, manufactured by Tokyo Keiki Co., Ltd.
This was performed using a shape viscometer.

【００２２】[0022]

【比較例１】実施例１記載と同じ設備および運転方法に
より、廃水の高沸点有機物の濃度が１４ｗｔ％および硫
酸アンモニウムの濃度が４０ｗｔ％となるように運転を
行ったところ、９日目に廃水の抜き出し導管７より安定
して廃水を抜き出すことができなくなり、大きな流量変
動を起こすようになった。更に１１日目には、導管３の
第一急冷部洗浄冷却水循環量が実施例１の運転時と同じ
スプレーノズル上流圧にした場合、１１０Ｔ／Ｈまで低
下していることが認められた。結果として、反応ガス冷
却洗浄工程を安定且つ連続的に運転することができなか
った。なおこのときの廃水の高沸点有機物および硫酸ア
ンモニウムの濃度を測定したところ、それぞれ１４．４
ｗｔ％および４０．２ｗｔ％であった。[Comparative Example 1] Using the same equipment and operating method as described in Example 1, the wastewater was operated so that the concentration of high-boiling organic matter was 14 wt% and the concentration of ammonium sulfate was 40 wt%. The wastewater cannot be stably extracted from the extraction conduit 7, resulting in a large fluctuation in the flow rate. Further, on the eleventh day, it was confirmed that when the circulation amount of the cooling water in the first quenching portion of the conduit 3 was set to the same upstream pressure of the spray nozzle as that in the operation of Example 1, it decreased to 110 T / H. As a result, the reaction gas cooling and washing step could not be operated stably and continuously. At this time, the concentrations of the high-boiling organic matter and ammonium sulfate in the wastewater were measured, and were 14.4 respectively.
wt% and 40.2 wt%.

【００２３】また、上記の運転で得られた導管７の廃水
を１リットルのビーカーに採取後、更に水分を蒸発さ
せ、高沸点有機物および硫酸アンモニウムを濃縮した。
濃縮後の廃水中の高沸点有機物および硫酸アンモニウム
の濃度を測定したところ、それぞれ１４. ２ｗｔ％およ
び４０. ５ｗｔ％であった。この濃縮した廃水の粘度を
実施例２と同様の方法で測定したところ、廃水温度８５
℃の場合４０ｃｐであり、室温まで冷却した場合は、急
激に廃水の粘度が上昇し、測定できなかった。After collecting the waste water in the conduit 7 obtained in the above operation in a 1-liter beaker, the water was further evaporated to concentrate high-boiling organic substances and ammonium sulfate.
When the concentrations of the high-boiling organic matter and ammonium sulfate in the wastewater after concentration were measured, they were 14.2 wt% and 40.5 wt%, respectively. When the viscosity of the concentrated wastewater was measured by the same method as in Example 2, the wastewater temperature was 85%.
The temperature was 40 cp in the case of ° C, and when cooled to room temperature, the viscosity of the wastewater rapidly increased, and measurement was not possible.

【００２４】[0024]

【発明の効果】本発明は、アンモ酸化反応によりアクリ
ロニトリルまたはメタクリロニトリルを製造する方法に
おいて、反応ガス冷却洗浄工程または廃水抜き出し導管
での硫酸アンモニウムの結晶析出または高沸点有機物の
濃度増加による粘度上昇を抑えることで反応ガス冷却洗
浄工程での循環洗浄液量を安定に保ち、且つ反応ガス冷
却洗浄工程からの廃水抜き出し配管の詰まりを少なくす
ることができる。その結果、反応ガス冷却洗浄工程を安
定且つ連続的に運転することができる。According to the present invention, there is provided a method for producing acrylonitrile or methacrylonitrile by an ammoxidation reaction, wherein the increase in viscosity due to the precipitation of ammonium sulfate crystals or the increase in the concentration of high-boiling organic matter in a reaction gas cooling washing step or a wastewater extraction conduit is considered. By suppressing the amount, the amount of the circulating cleaning liquid in the reaction gas cooling and cleaning step can be kept stable, and the clogging of the wastewater extraction pipe from the reaction gas cooling and cleaning step can be reduced. As a result, the reaction gas cooling and cleaning step can be operated stably and continuously.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の反応ガス冷却洗浄工程で用いられる急
冷塔の一例のフローを示す図である。FIG. 1 is a diagram showing a flow of an example of a quenching tower used in a reaction gas cooling and washing step of the present invention.

【図２】本発明の請求項１記載の高沸点有機物、硫酸ア
ンモニウムおよび水の濃度範囲を斜線部で示す図であ
る。FIG. 2 is a diagram showing the concentration ranges of the high-boiling organic compound, ammonium sulfate and water according to claim 1 of the present invention by hatching.

【図３】本発明の請求項２記載の高沸点有機物、硫酸ア
ンモニウムおよび水の濃度範囲を斜線部で示す図であ
る。FIG. 3 is a diagram showing the concentration ranges of the high-boiling organic compound, ammonium sulfate and water according to claim 2 of the present invention by hatching.

【符号の説明】 １ 反応器から急冷塔への反応ガス導入導管 ２ 急冷塔 ３ 循環冷却水導管 ４ 循環冷却水の冷却器（冷却器が無くても良い） ５ 循環冷却水への硫酸供給導管 ６ 急冷塔で冷却洗浄された後の急冷塔出口ガス導管 ７ 循環冷却水の抜き出し導管 ８ 急冷塔への供給水導管[Explanation of Signs] 1 Reactor gas introduction conduit from reactor to quenching tower 2 Quenching tower 3 Circulating cooling water conduit 4 Circulating cooling water cooler (no cooler required) 5 Sulfuric acid supply conduit to circulating cooling water 6 Cooling tower outlet gas conduit after cooling and washing in quench tower 7 Circulating cooling water extraction conduit 8 Supply water conduit to quench tower

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 反応ガス冷却洗浄工程から排出される廃
水中の高沸点有機物の重量に対する硫酸アンモニウムの
重量が１．５７１４以上であるアンモ酸化反応によりア
クリロニトリルまたはメタクリロニトリルを製造する方
法において、該反応ガス冷却洗浄工程から排出される廃
水中の高沸点有機物、硫酸アンモニウムおよび水の重量
濃度が、高沸点有機物をｘ重量％、硫酸アンモニウムを
ｙ重量％および水をｚ重量％とした場合、ｘ＞０、ｙ＞
０、ｘ＋ｙ＋ｚ＝１００、ｙ≦０．００４３ｘ2 −０．
７６３ｘ＋４５．５７４、およびｙ≧１．５７１４ｘで
示される範囲で運転することを特徴とするアクリロニト
リルまたはメタクリロニトリルの製造方法。1. A method for producing acrylonitrile or methacrylonitrile by an ammoxidation reaction in which the weight of ammonium sulfate relative to the weight of high-boiling organic matter in wastewater discharged from a reaction gas cooling and washing step is 1.5714 or more. When the weight concentration of the high-boiling organic matter, ammonium sulfate and water in the wastewater discharged from the gas cooling cleaning step is x% by weight of the high-boiling organic substance, y% by weight of ammonium sulfate and z% by weight, x> 0, y>
0, x + y + z = 100, y ≦ 0.0043x 2 −0.
A process for producing acrylonitrile or methacrylonitrile, characterized by operating in the range indicated by 763x + 45.574 and y ≧ 1.5714x. 【請求項２】 水の濃度（ｚ重量％）が０＜ｚ≦８０の
範囲で運転することを特徴とする請求項１記載のアクリ
ロニトリルまたはメタクリロニトリルの製造方法。2. The process for producing acrylonitrile or methacrylonitrile according to claim 1, wherein the operation is carried out in a water concentration range (z% by weight) of 0 <z ≦ 80. 【請求項３】 運転が該廃水の比重を測定して工程管理
することを特徴とする請求項１または２記載のアクリロ
ニトリルまたはメタクリロニトリルの製造方法。3. The method for producing acrylonitrile or methacrylonitrile according to claim 1, wherein the operation measures the specific gravity of the wastewater to control the process.
JP10207087A 1998-07-08 1998-07-08 Production of acrylonitrile or methacrylonitrile Pending JP2000026390A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10207087A JP2000026390A (en) 1998-07-08 1998-07-08 Production of acrylonitrile or methacrylonitrile

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10207087A JP2000026390A (en) 1998-07-08 1998-07-08 Production of acrylonitrile or methacrylonitrile

Publications (1)

Publication Number Publication Date
JP2000026390A true JP2000026390A (en) 2000-01-25

Family

ID=16533991

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10207087A Pending JP2000026390A (en) 1998-07-08 1998-07-08 Production of acrylonitrile or methacrylonitrile

Country Status (1)

Country Link
JP (1) JP2000026390A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014162777A (en) * 2013-02-27 2014-09-08 Mitsubishi Rayon Co Ltd Method for adding acidic solution
JP2015098455A (en) * 2013-11-19 2015-05-28 旭化成ケミカルズ株式会社 Method for producing unsaturated nitrile
JP2020111604A (en) * 2014-09-29 2020-07-27 イネオス ユーロープ アクチェンゲゼルシャフト Evaporation system for process stream

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014162777A (en) * 2013-02-27 2014-09-08 Mitsubishi Rayon Co Ltd Method for adding acidic solution
JP2015098455A (en) * 2013-11-19 2015-05-28 旭化成ケミカルズ株式会社 Method for producing unsaturated nitrile
JP2020111604A (en) * 2014-09-29 2020-07-27 イネオス ユーロープ アクチェンゲゼルシャフト Evaporation system for process stream
JP7096283B2 (en) 2014-09-29 2022-07-05 イネオス ユーロープ アクチェンゲゼルシャフト Evaporation system for process flow
JP2022125103A (en) * 2014-09-29 2022-08-26 イネオス ユーロープ アクチェンゲゼルシャフト Evaporation system for process stream

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