JPS6363273B2 - - Google Patents
Info
- Publication number
- JPS6363273B2 JPS6363273B2 JP8611580A JP8611580A JPS6363273B2 JP S6363273 B2 JPS6363273 B2 JP S6363273B2 JP 8611580 A JP8611580 A JP 8611580A JP 8611580 A JP8611580 A JP 8611580A JP S6363273 B2 JPS6363273 B2 JP S6363273B2
- Authority
- JP
- Japan
- Prior art keywords
- ammonium sulfate
- oil
- wastewater
- gas
- acrylonitrile
- 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.)
- Expired
Links
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 58
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 48
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 48
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 claims description 25
- 239000013078 crystal Substances 0.000 claims description 24
- 239000002351 wastewater Substances 0.000 claims description 22
- 239000000243 solution Substances 0.000 claims description 15
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 10
- 239000012047 saturated solution Substances 0.000 claims description 6
- 239000006227 byproduct Substances 0.000 claims description 2
- 238000004065 wastewater treatment Methods 0.000 claims description 2
- 239000003921 oil Substances 0.000 description 41
- 239000007789 gas Substances 0.000 description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 23
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 21
- 239000007788 liquid Substances 0.000 description 21
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 14
- 238000002425 crystallisation Methods 0.000 description 14
- 230000008025 crystallization Effects 0.000 description 14
- 238000000926 separation method Methods 0.000 description 13
- 238000005406 washing Methods 0.000 description 13
- LELOWRISYMNNSU-UHFFFAOYSA-N hydrogen cyanide Chemical compound N#C LELOWRISYMNNSU-UHFFFAOYSA-N 0.000 description 12
- 238000001816 cooling Methods 0.000 description 11
- 238000002485 combustion reaction Methods 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 238000009835 boiling Methods 0.000 description 8
- 229910021529 ammonia Inorganic materials 0.000 description 7
- 238000004090 dissolution Methods 0.000 description 7
- 239000000446 fuel Substances 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 4
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 4
- 239000012495 reaction gas Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 239000000295 fuel oil Substances 0.000 description 2
- 239000012452 mother liquor Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
Description
【発明の詳細な説明】
本発明は、プロピレンとアンモニアを酸素を用
いて触媒の存在下で酸化してアクリロニトリルを
製造する方法において生成する廃水を処理する方
法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating wastewater produced in a process for producing acrylonitrile by oxidizing propylene and ammonia with oxygen in the presence of a catalyst.
更に詳細には、本発明は、アクリロニトリル製
造のさいに生成するガスを、硫酸水溶液で洗浄
し、得られた廃水に硫安結晶を添加溶解もしくは
硫安飽和溶液を注入して油分を分離除去するか、
または得られた廃水から油分の一部を放散させた
残廃水に硫安結晶を添加溶解、もしくは硫安飽和
溶液を注入して更に未溶解になつた油分を分離除
去し、アクリロニトリル製造の際に生じる副産物
や前記分離油分を焼却する焼却炉よりの高温排ガ
スを断熱冷却して得られた低温高湿ガスを熱源と
する蒸発型結晶缶へ供給し、得られた硫安結晶も
しくは硫安飽和溶液を循環使用することを特徴と
する、アクリロニトリル製造のさいの廃水処理方
法に関する。 More specifically, the present invention involves washing the gas generated during the production of acrylonitrile with an aqueous sulfuric acid solution, adding and dissolving ammonium sulfate crystals in the resulting wastewater, or injecting a saturated ammonium sulfate solution to separate and remove the oil;
Alternatively, ammonium sulfate crystals are added and dissolved in the residual wastewater after dissipating some of the oil from the obtained wastewater, or a saturated ammonium sulfate solution is injected to separate and remove the undissolved oil, resulting in a by-product produced during the production of acrylonitrile. The high-temperature exhaust gas from the incinerator that incinerates the separated oil is adiabatically cooled and the resulting low-temperature, high-humidity gas is supplied to an evaporative crystallizer using the heat source, and the resulting ammonium sulfate crystals or ammonium sulfate saturated solution is recycled and used. The present invention relates to a method for treating wastewater during acrylonitrile production, which is characterized by the following.
従来、プロピレンとアンモニアを酸素を用いて
触媒の存在下で酸化してアクリロニトリルを製造
する方法においては、生成する反応ガスはアクリ
ロニトリル、アセトニトリル、青酸、アンモニア
および重合化合物等を含んでいる。従つて、アク
リロニトリルの効果的な回収を行うためには、先
づアンモニアおよび重合化合物を生成ガスより分
離し、次いでアクリロニトリル、アセトニトリル
および青酸を分離する方法がとられている。一
方、、アンモニアとプロピレンの反応によつて生
じた水は反応系外に排出する必要がある。この排
水廃液中には多くの有害物質を約10％含んでお
り、直接微生物処理することは不可能であり、そ
れ故工業的には燃料を用いて高温分解する方法が
とられている。しかし、このような処理方法は、
前記排水廃液中の有機物含有量が少ないので、多
量の燃料例えば灯油または重油を必要とし著るし
く不経済である。 Conventionally, in a method for producing acrylonitrile by oxidizing propylene and ammonia with oxygen in the presence of a catalyst, the generated reaction gas contains acrylonitrile, acetonitrile, hydrocyanic acid, ammonia, polymeric compounds, and the like. Therefore, in order to effectively recover acrylonitrile, a method is used in which ammonia and polymeric compounds are first separated from the produced gas, and then acrylonitrile, acetonitrile, and hydrocyanic acid are separated. On the other hand, water generated by the reaction of ammonia and propylene needs to be discharged from the reaction system. This waste water contains about 10% of many harmful substances, and it is impossible to directly treat them with microorganisms, so industrially, high-temperature decomposition using fuel is used. However, this processing method
Since the content of organic matter in the waste water is low, a large amount of fuel such as kerosene or heavy oil is required, which is extremely uneconomical.
本発明の目的は、前記アクリロニトリルの製造
方法において、標準的な生成反応ガスの水洗処理
によつて生じる廃水の効果的な処理方法に関する
ものである。 An object of the present invention is to provide an effective method for treating wastewater generated by the standard water washing treatment of the reaction gas produced in the method for producing acrylonitrile.
この本発明の目的は、前記廃水液に硫安結晶を
添加、もしくは硫安飽和溶液を注入することによ
り達成することができる。この硫安結晶の添加、
もしくは硫安飽和溶液の注入による利点を列挙す
れば次の如くである。 This object of the present invention can be achieved by adding ammonium sulfate crystals or injecting a saturated ammonium sulfate solution to the wastewater liquid. The addition of this ammonium sulfate crystal,
Alternatively, the advantages of injecting a saturated ammonium sulfate solution are as follows.
(1) 前記廃水液に硫安結晶を添加もしくは硫安飽
和溶液を注入により、硫安がある濃度以上にな
れば重合物や有害物質等すなわちCOD成分が
油分となつて分離除去される。(1) By adding ammonium sulfate crystals or injecting a saturated ammonium sulfate solution to the wastewater liquid, when the ammonium sulfate concentration exceeds a certain level, polymers, harmful substances, etc., ie, COD components, are separated and removed as oil.
(2) 前記(1)の如く油分を分離除去した廃水液を濃
縮した際に生じる凝縮液中のCOD量は、前記
(1)の如くして油分を分離除去しない廃水液の
COD量に比較して極めて少ない。(2) The amount of COD in the condensate produced when the wastewater liquid from which oil has been separated and removed as described in (1) above is concentrated.
(1) of wastewater liquid in which the oil content is not separated and removed.
It is extremely small compared to the amount of COD.
(3) 前記(2)の凝縮液中のCOD成分を、通常行わ
れる活性炭等で吸着処理した場合に、その吸着
能力は硫安結晶添加、もしくは硫安飽和溶液注
入処理しない場合より極めて良好である。(3) When the COD component in the condensate described in (2) above is adsorbed using activated carbon, etc., which is commonly performed, the adsorption ability is much better than when no ammonium sulfate crystals are added or ammonium sulfate saturated solution is not injected.
(4) 前記(1)の分離した油分は、助燃料油として利
用できる。(4) The oil separated in (1) above can be used as an auxiliary fuel oil.
(5) 硫安結晶添加、もしくは硫安飽和溶液注入処
理した水溶液より得られる硫安結晶は、窒素量
21.1％（理論量21.5％）以上であり、かつ純白
である。(5) Ammonium sulfate crystals obtained from an aqueous solution treated with ammonium sulfate crystal addition or ammonium sulfate saturated solution injection have a nitrogen content.
It is 21.1% (theoretical amount 21.5%) or more and is pure white.
(6) 廃水液を濃縮するのに必要な熱量は、アクリ
ロニトリル製造工程より得られる排ガス中の低
沸物また前記(1)の硫安結晶添加もしくは硫安飽
和溶液注入により分離された油分を燃焼するこ
とにより得られる高温ガス（約900℃〜約1000
℃）に、水を加えて断熱冷却して得られたスチ
ーム類似の低温高湿ガス（約90℃）を加熱源と
して用いることができ、プラント外よりの燃料
供給をほとんど行なわずに処理が可能である。(6) The amount of heat required to concentrate the wastewater liquid can be obtained by burning the low-boiling substances in the exhaust gas obtained from the acrylonitrile manufacturing process or the oil separated by adding ammonium sulfate crystals or injecting a saturated ammonium sulfate solution as described in (1) above. High-temperature gas obtained by
A steam-like low-temperature, high-humidity gas (approximately 90°C) obtained by adding water and adiabatic cooling can be used as a heating source, making it possible to process with almost no fuel supply from outside the plant. It is.
(7) 廃水液中には既に硫安が約５％〜約７％含ま
れているが、これも同時に回収することができ
る。(7) The waste water already contains about 5% to about 7% ammonium sulfate, which can also be recovered at the same time.
(8) 硫安は溶解度が大きく油分を分離し易い。(8) Ammonium sulfate has high solubility and oil can be easily separated.
(9) 硫安結晶、もしくは硫安飽和溶液の循環使用
が可能である。(9) It is possible to recycle ammonium sulfate crystals or ammonium sulfate saturated solutions.
次ぎに、本発明を実施するための一態様を示め
す第１図のフロシートを用いて本発明方法を詳細
に説明する。 Next, the method of the present invention will be explained in detail using the flow sheet shown in FIG. 1 showing one embodiment of the present invention.
アンモニアとプロピレンを触媒の存在下酸素中
で反応させた場合に、アクリロニトリル１Kgに対
して1.7〜1.8倍の水を生成する。この水を含んだ
温度の高い反応ガスを熱交換し、かつ目的生成物
であるアクリロニトリルを回収した後の400〜600
℃の温度の排ガスを廃熱ボイラーで熱交換して約
150℃〜約200℃にし、急速冷却塔１内に排ガス入
口１ａより供給する。急速冷却塔１に入つた排ガ
スは、該冷却塔の塔頂より降下する洗浄用水、硫
酸その他を含む循環液によつて向流で冷却されな
がら塔頂の１ｂから約82℃〜約88℃の温度で出て
行き８のコンデンサーを経て排ガス中の水分を完
全に除き排出される。急速冷却塔１には循環ポン
プｐ−１が接続されており、このポンプの吸込み
側に硫酸注入パイプ１ｃと洗浄用水注入パイプ１
ｄが取付けてあり、循環ポンプｐ−１の吐出し側
には放散塔２へつながる配管２ａと急速冷却塔１
へつながる配管１ｅが夫々連結されており、該冷
却塔内では適当な循環量対ガス比を保持しながら
運転されており、補給洗浄水によつて断熱冷却さ
れた排ガスは前述の如く１ｂより出て行き８のコ
ンデンサーを経て水分除去後排出される。 When ammonia and propylene are reacted in oxygen in the presence of a catalyst, 1.7 to 1.8 times as much water is produced per 1 kg of acrylonitrile. 400 to 600 after heat-exchanging this high-temperature reaction gas containing water and recovering the target product acrylonitrile.
Exhaust gas at a temperature of ℃ is exchanged with a waste heat boiler to generate approximately
The temperature is 150°C to about 200°C, and the exhaust gas is supplied into the rapid cooling tower 1 from the exhaust gas inlet 1a. The exhaust gas that has entered the rapid cooling tower 1 is cooled in a countercurrent by circulating liquid containing washing water, sulfuric acid, etc. that descends from the top of the cooling tower, and cools from the top 1b to about 82°C to about 88°C. It leaves the exhaust gas at a high temperature, passes through condenser 8, completely removes moisture from the exhaust gas, and is discharged. A circulation pump p-1 is connected to the rapid cooling tower 1, and a sulfuric acid injection pipe 1c and a cleaning water injection pipe 1 are connected to the suction side of this pump.
d is installed, and on the discharge side of the circulation pump p-1, a pipe 2a connected to the stripping tower 2 and a rapid cooling tower 1 are installed.
The cooling tower is operated while maintaining an appropriate circulation rate to gas ratio, and the exhaust gas, which has been adiabatically cooled by make-up wash water, exits from 1b as described above. The water then passes through condenser 8 and is discharged after water is removed.
急速冷却塔１中に供給された排ガス中に含まれ
るアンモニアは該冷却塔の塔頂からの前記循環液
に含まれる硫酸によつて中和溶解され、排ガス中
のその他の物質は前記循環液に溶解したり吸収さ
れる。この溶解吸収液には、アクリロニトリル、
アセトニトリル、青酸、重合物および硫安等が含
まれ、硫安濃度は通常２％〜約８％である。 Ammonia contained in the exhaust gas supplied to the rapid cooling tower 1 is neutralized and dissolved by sulfuric acid contained in the circulating liquid from the top of the cooling tower, and other substances in the exhaust gas are dissolved in the circulating liquid. Dissolved or absorbed. This dissolved and absorbed solution contains acrylonitrile,
Contains acetonitrile, hydrocyanic acid, polymers, ammonium sulfate, etc., and the ammonium sulfate concentration is usually 2% to about 8%.
この溶解吸収液は２ａを通つて放散塔２の上部
へ供給され、放散塔２の下部よりのスチーム２ｄ
により間接加熱されて、前記溶解吸収液中の低沸
物は２ｂを経て焼却炉１０に供給される。 This dissolved and absorbed liquid is supplied to the upper part of the stripping tower 2 through 2a, and steam 2d from the lower part of the stripping tower 2
The low-boiling substances in the dissolved and absorbed liquid are indirectly heated by the incinerator 10 and supplied to the incinerator 10 via 2b.
放散塔２において低沸物を放散した残液は、放
散塔２の塔底より２ｃを経由して硫安結晶溶解槽
（あるいは硫安飽和溶液を用いる場合は硫安溶液
混合槽）３に送られ、そこで結晶槽１３で晶出し
遠心分離機７で分離された硫安結晶の一部を溶解
（あるいは、分離母液（硫安飽和溶液）の一部を
注入混合して油分離槽４へ移される。この油分離
槽４では、硫酸濃度が増加したために、油分およ
び重合物等の溶解度が低下してそれらが更に分離
してくる。分離した油分等は４ａより油分貯槽１
２に貯え、ｐ−３を通つて１０ａのアトマイザー
により１０ｂのアトマイズ媒体（蒸気または圧縮
空気等）による焼却炉１０内に噴露される。 The residual liquid from which low-boiling substances have been diffused in the stripping tower 2 is sent from the bottom of the stripping tower 2 via 2c to the ammonium sulfate crystal dissolution tank (or ammonium sulfate solution mixing tank when using a saturated ammonium sulfate solution) 3, where it is Part of the ammonium sulfate crystals crystallized in the crystallization tank 13 and separated by the centrifuge 7 is dissolved (or a part of the separation mother liquor (saturated ammonium sulfate solution) is injected and mixed and transferred to the oil separation tank 4. This oil separation In tank 4, as the sulfuric acid concentration increases, the solubility of oils and polymers decreases, causing them to separate further.The separated oils are transferred from 4a to oil storage tank 1.
2 and is ejected into the incinerator 10 by an atomizer 10a through p-3 with an atomizing medium (steam, compressed air, etc.) 10b.
焼却炉１０は、９ａを通して空気、９ｂを通し
て燃料および９ｃを通してアトマイズ媒体が夫々
供給されている燃焼炉９を有している。 The incinerator 10 has a combustion furnace 9 which is supplied with air through 9a, fuel through 9b and an atomizing medium through 9c.
焼却炉１０に供給された２ｂからの低沸物およ
び１０ａからの油分は、燃焼炉９からの高温ガス
によつて燃焼して高温ガスとなり、１１ａを通じ
て洗浄塔１１に入り、洗浄塔１１の上部１１ｄよ
り洗浄水を供給し、この洗浄水と向流的に接触さ
せて前記高温ガス中に含まれた一部固形物等を溶
解した洗浄廃水として１１ｃを通じて系外に排出
される。一方、前述の如く、洗浄塔１１におい
て、洗浄水と向流的に接触され一部固形物等を溶
解された残りの高温ガスは、洗浄水のためにやゝ
低温の高湿ガスとなり１１ｂより濃縮缶５の加熱
部に導かれて、油分離槽４からｐ−２を経由して
濃縮缶５に入つてくる油分分離除去後の硫安の多
い水溶液の加熱源として利用される。これは、１
１ｂよりのやゝ低温（約90℃）の高湿ガス中の水
分を凝縮させることにより行われ、水分凝縮後の
排ガスは５ａを通つて排出される。 The low-boiling substances from 2b and the oil from 10a supplied to the incinerator 10 are combusted by the high-temperature gas from the combustion furnace 9 to become high-temperature gas, enter the cleaning tower 11 through 11a, and enter the upper part of the cleaning tower 11. Washing water is supplied from 11d, and is brought into countercurrent contact with the washing water to dissolve some of the solids contained in the high-temperature gas, and is discharged to the outside of the system through 11c as washing wastewater. On the other hand, as mentioned above, in the washing tower 11, the remaining high-temperature gas that has been brought into contact with the washing water in a countercurrent manner and some of the solids, etc. have been dissolved, becomes a relatively low-temperature, high-humidity gas due to the washing water, and from 11b. It is used as a heating source for the ammonium sulfate-rich aqueous solution after oil separation and removal, which is led to the heating part of the concentrator 5 and enters the concentrator 5 from the oil separation tank 4 via p-2. This is 1
This is done by condensing the moisture in the humid gas at a slightly lower temperature (approximately 90°C) than 1b, and the exhaust gas after condensing the moisture is discharged through 5a.
濃縮缶５において、油分離槽４からｐ−２を経
て入つてきた硫安の多い水溶液は所定の濃度に濃
縮され、次いで５ｂを通つて結晶槽１３に移され
る。この濃縮液は、結晶槽１３において、濃縮缶
５の上部から５ｃを通つて結晶槽１３の加熱弊に
入つてくる水蒸気により更に加熱濃縮されて硫安
結晶を生成する。結晶槽１３の加熱源として５ｃ
から入つてきた水蒸気は１３ａより排出され、ま
た結晶槽１３で発生した水蒸気は１３ｂから取り
出されコンデンサー６を通つて排出される。この
蒸発晶析操作によつて生成した濃縮液は、既に放
散塔２、溶解槽（または混合槽）３および油分離
槽４等により低沸物を除去しているので、COD
成分の低い濃縮液であり、通常の廃水処理技術例
えば活性炭処理等によつてCOD成分の除去が可
能である。 In the concentrator 5, the ammonium sulfate-rich aqueous solution that has entered from the oil separation tank 4 via p-2 is concentrated to a predetermined concentration, and then transferred to the crystallization tank 13 through 5b. This concentrated liquid is further heated and concentrated in the crystallization tank 13 by water vapor that enters the heating chamber of the crystallization tank 13 through the upper part of the concentration can 5 through 5c, thereby producing ammonium sulfate crystals. 5c as a heating source for the crystallization tank 13
The water vapor that has entered the tank is discharged from 13a, and the water vapor generated in crystallization tank 13 is taken out from 13b and discharged through condenser 6. The concentrated liquid produced by this evaporation crystallization operation has already had low-boiling substances removed in the stripping tower 2, dissolution tank (or mixing tank) 3, oil separation tank 4, etc., so the COD
It is a concentrated liquid with a low concentration of COD components, and COD components can be removed using conventional wastewater treatment techniques such as activated carbon treatment.
結晶槽１３において生成した硫安結晶は、１３
ｃより遠心分離機７に入つて分離され、分離され
た硫安結晶の一部は７ａより乾燥機へ、一部は７
ｂより溶解槽３へ送られる。硫安飽和溶液を油分
離に用いる場合は分離機分離母液の一部を７b′よ
り混合槽３へ送る。濾液は、その大部分を７ｃよ
り結晶槽１３へ戻し、一部は油分除去のために溶
解槽３へ返送される。 The ammonium sulfate crystals generated in the crystallization tank 13 are
A part of the separated ammonium sulfate crystals enters the centrifuge 7 from c and is separated, and a part of the separated ammonium sulfate crystals goes to the dryer from 7a, and a part goes to the dryer from 7a.
It is sent to the dissolution tank 3 from b. When a saturated ammonium sulfate solution is used for oil separation, a part of the mother liquor separated by the separator is sent to the mixing tank 3 from 7b'. Most of the filtrate is returned to the crystallization tank 13 through 7c, and a part is returned to the dissolution tank 3 for oil removal.
以上の如く、非常にCODの高いかつ硫安を多
く含んだアクリロニトリル製造工程から排出され
る廃液（COD値通常30000〜40000p.p.m.）から、
有効な肥料としての硫安を回収しながら、焼却炉
において用いられる燃料に相当する油分を回収
し、また有害成分の多くはストリツピングにより
系外へ取り出し、回収した油分を一部燃料源とし
て運転されている焼却炉で燃焼処理を行ない、そ
の高温排ガス等を硫安結晶生成のための加熱源と
して用い、かつ得られた濃縮液のCODは非常に
低い値（1500〜3000p.p.m.）とするシステムを提
供することができる。 As mentioned above, from the waste liquid discharged from the acrylonitrile manufacturing process which has a very high COD and contains a lot of ammonium sulfate (COD value usually 30,000 to 40,000 p.pm),
While recovering ammonium sulfate, which is an effective fertilizer, the oil equivalent to the fuel used in the incinerator is also recovered, and many of the harmful components are removed from the system by stripping, and the plant is operated using the recovered oil as a fuel source. We provide a system that performs combustion treatment in an incinerator that uses the high-temperature exhaust gas, etc., as a heating source to generate ammonium sulfate crystals, and that the COD of the obtained concentrated liquid is extremely low (1500 to 3000 p.pm). can do.
実施例
アクリロニトリルの生産量7000Kg／時間で運転
されている反応塔より出てくる反応ガスからアク
リロニトリルを回収した後の排ガスを、１ａより
急速冷却塔１に入れ、１ｃ，１ｄ，ｐ−１および
１ｅを経由する硫酸を含む水溶液で冷却洗浄し、
14200Kg／時間の廃水を得た。この廃水中にはア
クリロニトリル43Kg、アセトニトリル8.5Kg、青
酸24Kg、硫安860Kgおよび油分430Kgを含んでお
り、そのCODは49000p.p.m.であつた。Example After recovering acrylonitrile from the reaction gas coming out of a reaction tower operating at an acrylonitrile production rate of 7000 kg/hour, the exhaust gas is fed into the rapid cooling tower 1 from 1a, and is then heated to 1c, 1d, p-1 and 1e. Cool and wash with an aqueous solution containing sulfuric acid via
14200Kg/hour of wastewater was obtained. This wastewater contained 43 kg of acrylonitrile, 8.5 kg of acetonitrile, 24 kg of hydrocyanic acid, 860 kg of ammonium sulfate, and 430 kg of oil, and its COD was 49,000 p.pm.
この廃水を取り出し、直径700mm高さ6000mmの
放散塔２へ２ａを通して入れた。この放散塔２に
おいてスチームを用いて間接加熱し、留出率10％
のときCOD成分除去率は30％であつた。低沸物
を放散した後の液は２ｃを通して容積２m3の溶解
槽３へ連続的に移した。一方、遠心分離機７を用
いて結晶槽１３で生成した硫安を5200Kg／時間の
割合で連続的に供給し、溶解槽３の液の温度を60
℃とし硫安濃度の高い溶液にした後８m3溶積の油
分離槽４へ送り、ここで油分総量の89％の油分を
分離した。この油分の発熱量は約8300Kcal／Kg
であつた。また、この油分の成分は次の如くであ
つた。 This waste water was taken out and introduced into a diffusion tower 2 having a diameter of 700 mm and a height of 6000 mm through 2a. In this stripping tower 2, indirect heating is performed using steam to achieve a distillation rate of 10%.
At that time, the COD component removal rate was 30%. The liquid after dissipating the low-boiling substances was continuously transferred to the dissolution tank 3 having a volume of 2 m 3 through 2c. On the other hand, using the centrifuge 7, ammonium sulfate produced in the crystallization tank 13 was continuously supplied at a rate of 5200 kg/hour, and the temperature of the liquid in the dissolution tank 3 was raised to 60 kg/hour.
℃ and made into a solution with a high ammonium sulfate concentration, it was sent to an oil separation tank 4 with a volume of 8 m 3 where 89% of the total oil content was separated. The calorific value of this oil is approximately 8300Kcal/Kg
It was hot. The components of this oil were as follows.
アクリロニトリル 2.6％（重量）
アセトニトリル 0.5〃 〃
青 酸 1.4〃 〃
硫 安 12.8〃 〃
油 分 57.9〃 〃
水 分 24・8〃 〃
計 100.0〃 〃
この油分を油分貯槽１２に入れ、ｐ−３を経由
して焼却炉１０に供給した。この場合に炉内温度
が高温となり焼却炉１０を構成している耐火物に
悪影響を与えるために、炉内温度を適温に保つよ
うに、燃焼炉９の燃焼ガスおよび２ｂからの低沸
物の量を適当に調節した。それ故、この焼却炉１
０（焼却炉寸法：2800φ×8000H）においては次
の条件で焼却を行つた。Acrylonitrile 2.6 % (weight) acetonitrile 0.5〃 〃 green acid 1.4 〃 sulfate 12.8〃 〃 Oil sequence 57.9〃 〃 〃 〃 〃 計 計 計 計 計 計 計and supplied to the incinerator 10. In this case, the temperature inside the furnace becomes high and has an adverse effect on the refractories that make up the incinerator 10, so in order to keep the inside temperature at an appropriate temperature, the combustion gas from the combustion furnace 9 and the low boiling point from 2b are removed. The amount was adjusted appropriately. Therefore, this incinerator 1
0 (incinerator dimensions: 2800φ x 8000H), incineration was performed under the following conditions.
９ａからの空気：6500Kg／時間
９ｂからの燃料：40Kg／時間
９ｃからのアトマイズ
媒体であるスチーム：26Kg／時間
１０ａからの油分：383Kg／時間
２ｂからの低沸物：60Kg／時間
この条件で、焼却炉１０内温度1000℃および空
気過剰率1.3で焼却を行い約1000℃の燃焼高温ガ
ス7180Nm3／時間が得られた。この熱焼高温ガス
中の青酸、アクリロニトリル、アセトニトリルの
濃度はいずれも許容量以下であつた。この燃焼高
温ガスを１１ａから洗浄塔１１に入れ、１１ｄよ
り洗浄用水を入れた。前記燃焼高温ガス中には亜
硫酸ガスがあるので洗浄用水は苛性ソーダを溶解
したものを用いた。前記燃焼高温ガス中の一部固
形物等を溶解した洗浄廃水は１１ｃから排出し、
一方、洗浄後のガス（温度87℃）は、青酸、アク
リロニトリル、アセトニトリルの濃度はいずれも
許容量以下であり、１１ｂより濃縮缶に入れた。Air from 9a: 6500Kg/hour Fuel from 9b: 40Kg/hour Atomization from 9c Steam as medium: 26Kg/hour Oil from 10a: 383Kg/hour Low boiling matter from 2b: 60Kg/hour Under these conditions, Incineration was performed at an internal temperature of the incinerator 10 of 1000°C and an excess air ratio of 1.3, yielding 7180 Nm 3 /hour of combustion high-temperature gas at about 1000°C. The concentrations of hydrocyanic acid, acrylonitrile, and acetonitrile in this hot sintering gas were all below permissible levels. This combustion high-temperature gas was introduced into the washing tower 11 from 11a, and washing water was introduced from 11d. Since the combustion high temperature gas contained sulfur dioxide gas, the cleaning water used was one in which caustic soda was dissolved. Washing waste water in which some solids etc. in the combustion high temperature gas have been dissolved is discharged from 11c,
On the other hand, the gas after cleaning (temperature: 87°C) had concentrations of hydrocyanic acid, acrylonitrile, and acetonitrile that were all below the allowable amount, and was put into the concentrator from 11b.
油分離槽４からの第２回目の油分を分離除去し
た硫安の多い水溶液（硫安濃度34％）をｐ−２を
通して濃縮缶５に入れ、１１ｂよりの低温高湿ガ
スにて加熱し濃縮を行つて硫安濃度46％に濃縮し
た。その濃縮液を５ｂより強制循環型結晶槽１３
に入れ温度55℃で白色の硫安結晶770Kg（窒素分
21.0％）を得た。結晶槽１３より発生した水蒸気
は200m2のコンデンサー６によつて凝縮し、得ら
れた凝縮液は茶色に着色しているがCOD成分は
1480p.p.m.であつた。この凝縮液を活性炭充填層
へ供給するとCOD成分は150p.p.m.になつた。 The aqueous solution containing a lot of ammonium sulfate (ammonium sulfate concentration 34%) from the oil separation tank 4 after the second oil separation was put into the concentrator 5 through p-2, and concentrated by heating with low-temperature and high-humidity gas from 11b. It was then concentrated to an ammonium sulfate concentration of 46%. The concentrated liquid is transferred from 5b to the forced circulation type crystallization tank 13.
770 kg of white ammonium sulfate crystals (nitrogen content
21.0%). The water vapor generated from the crystallization tank 13 is condensed in a 200 m 2 condenser 6, and the resulting condensate is colored brown, but contains no COD components.
It was 1480p.pm. When this condensate was fed to an activated carbon packed bed, the COD content was 150p.pm.
なお、実施の態様として、第１図に示すような
２重効用缶とすることが水バランスより考えて好
ましい。 As an embodiment, it is preferable to use a double-effect can as shown in FIG. 1 in view of water balance.
以上詳細に説明した如く、本発明方法を実施す
る場合には、アクリロニトリルの製造において生
じる廃液を濃縮および硫安晶出するのに要する熱
源として他から新しく供給することなく、焼却炉
１０より洗浄塔１１を経由して出てくる１１ｂよ
りの水蒸気および濃縮缶５よりの５ｃからの水蒸
気等を有効に利用でき、また硫安溶解槽３、油分
離槽４および油分貯槽１２等により前記廃液中の
油分を高度に分離することができ、かつ油分をあ
らかじめ充分に分離したために、濃縮缶５および
結晶槽１３の加熱部等に有機油分の付着等の問題
もなく、しかも高純度、純白の硫安結晶を回収す
ることができ、コンデンサー６における凝縮液の
CODも低く以後の処理も極めて容易である等の
特徴を有している。 As explained in detail above, when carrying out the method of the present invention, the waste liquid generated in the production of acrylonitrile is transferred from the incinerator 10 to the washing tower 11 as a heat source required for concentrating and crystallizing ammonium sulfate. The water vapor from 11b and the water vapor from 5c from the concentrator 5 can be effectively used, and the oil in the waste liquid can be removed by the ammonium sulfate dissolving tank 3, oil separation tank 4, oil storage tank 12, etc. Since the oil can be separated to a high degree and the oil has been sufficiently separated in advance, there is no problem such as adhesion of organic oil to the heating parts of the concentrator 5 and the crystallization tank 13, and high-purity, pure white ammonium sulfate crystals can be recovered. of condensate in condenser 6.
It has the characteristics of low COD and subsequent processing is extremely easy.
図面は本発明を実施するのに使用する装置のフ
ロシートの一態様を示す。
１……急速冷却塔、２……放散塔、３……溶解
槽、４……油分離槽、５……濃縮缶、６……コン
デンサー、７……遠心分離機、８……コンデンサ
ー、９……燃焼炉、１０……焼却炉、１１……洗
浄塔、１２……油分貯槽、１３……結晶槽。
The drawing depicts one embodiment of a flowsheet of equipment used to carry out the invention. 1... Rapid cooling tower, 2... Stripping tower, 3... Dissolution tank, 4... Oil separation tank, 5... Concentrator, 6... Condenser, 7... Centrifugal separator, 8... Condenser, 9 ... Combustion furnace, 10 ... Incinerator, 11 ... Cleaning tower, 12 ... Oil storage tank, 13 ... Crystallization tank.
Claims (1)
を、硫酸水溶液で洗浄し、得られた廃水に硫安結
晶を添加溶解、もしくは硫安飽和溶液を注入して
油分を分離除去するか、または得られた廃水から
油分の一部を放散させた残廃水に前記同様硫安結
晶を添加溶解もしくは硫安飽和溶液を注入して更
に未溶解になつた油分を分離除去し、アクリロニ
トリル製造の際に生じる副産物や前記分離油分を
焼去する焼却炉よりの高温排ガスを断熱冷却して
得られた低温高湿ガスを熱源とする蒸発型結晶缶
へ供給し、得られた硫安結晶もしくは硫安飽和溶
液を循環使用することを特徴とする、アクリロニ
トリル製造のさいの廃水処理方法。1. Gas generated during acrylonitrile production is washed with an aqueous sulfuric acid solution, and ammonium sulfate crystals are added and dissolved in the resulting wastewater, or a saturated ammonium sulfate solution is injected to separate and remove the oil, or the oil is removed from the resulting wastewater. Ammonium sulfate crystals are added and dissolved in the residual wastewater from which a part of the acrylonitrile is dissipated, and ammonium sulfate crystals are added and dissolved in the same manner as described above, or ammonium sulfate saturated solution is injected, and the undissolved oil is separated and removed, and the by-products generated during acrylonitrile production and the separated oil are burned. The method is characterized in that the high-temperature exhaust gas from the incinerator is adiabatically cooled and the resulting low-temperature, high-humidity gas is supplied to an evaporative crystallizer using the heat source, and the resulting ammonium sulfate crystals or ammonium sulfate saturated solution is recycled and used. , a wastewater treatment method during acrylonitrile production.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8611580A JPS5712886A (en) | 1980-06-25 | 1980-06-25 | Disposal of waste water in production of acrylonitrile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8611580A JPS5712886A (en) | 1980-06-25 | 1980-06-25 | Disposal of waste water in production of acrylonitrile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5712886A JPS5712886A (en) | 1982-01-22 |
| JPS6363273B2 true JPS6363273B2 (en) | 1988-12-06 |
Family
ID=13877690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8611580A Granted JPS5712886A (en) | 1980-06-25 | 1980-06-25 | Disposal of waste water in production of acrylonitrile |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5712886A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07103593B2 (en) * | 1990-06-06 | 1995-11-08 | 株式会社小松製作所 | Control device and method for loading work vehicle |
| JP2003232511A (en) * | 2002-02-06 | 2003-08-22 | Tsukishima Kikai Co Ltd | Combustion method and combustion apparatus for waste liquid |
-
1980
- 1980-06-25 JP JP8611580A patent/JPS5712886A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5712886A (en) | 1982-01-22 |
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