JPS6154022B2 - - Google Patents
Info
- Publication number
- JPS6154022B2 JPS6154022B2 JP54051979A JP5197979A JPS6154022B2 JP S6154022 B2 JPS6154022 B2 JP S6154022B2 JP 54051979 A JP54051979 A JP 54051979A JP 5197979 A JP5197979 A JP 5197979A JP S6154022 B2 JPS6154022 B2 JP S6154022B2
- Authority
- JP
- Japan
- Prior art keywords
- acetonitrile
- column
- oxazole
- water
- weight
- 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
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 claims description 144
- ZCQWOFVYLHDMMC-UHFFFAOYSA-N Oxazole Chemical compound C1=COC=N1 ZCQWOFVYLHDMMC-UHFFFAOYSA-N 0.000 claims description 31
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 20
- 238000004821 distillation Methods 0.000 claims description 16
- 239000002994 raw material Substances 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 7
- 238000000895 extractive distillation Methods 0.000 claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- 239000012535 impurity Substances 0.000 description 8
- 238000009835 boiling Methods 0.000 description 7
- 238000011084 recovery Methods 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 5
- 229910021529 ammonia Inorganic materials 0.000 description 5
- 239000006227 byproduct Substances 0.000 description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010992 reflux Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- GYCMBHHDWRMZGG-UHFFFAOYSA-N Methylacrylonitrile Chemical compound CC(=C)C#N GYCMBHHDWRMZGG-UHFFFAOYSA-N 0.000 description 2
- LELOWRISYMNNSU-UHFFFAOYSA-N hydrogen cyanide Chemical compound N#C LELOWRISYMNNSU-UHFFFAOYSA-N 0.000 description 2
- 229910017053 inorganic salt Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical group CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 1
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007700 distillative separation Methods 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
本発明は、不純分としてオキサゾールを含有す
る粗製アセトニトリルからオキサゾールを除去
し、純粋なアセトニトリルを得る方法、さらに詳
しくいえば単一の蒸留操作により粗製アセトニト
リルからオキサゾールその他の不純分を除去して
効率よく純粋なアセトニトリルを回収する方法に
関するものである。
プロピレン又はイソブチレンと酸素とアンモニ
アの気相接触反応によりアクリロニトリル又はメ
タクリロニトリルを製造する方法が知られている
が、この方法において得られる反応生成物中に
は、アクリロニトリル又はメタクリロニトリルの
ほかに、副生したアセトニトリル及び少量のオキ
サゾールが含まれている。このようなアクリロニ
トリルからアセトニトリルやオキサゾールを分離
するには、通常、水による抽出蒸留が行われ、こ
の際副生物として、アセトニトリルとオキサゾー
ルを含む水溶液が得られる。
ところで、この副生アセトニトリルを工業用原
料として使用するには、その中のオキサゾールを
除去しなければならないがオキサゾールの沸点が
アセトニトリルのそれと近接しているため精留に
よつてこれを完全に除去することは非常に困難で
ある。従来、この副生アセトニトリル中のオキサ
ゾールを除去する方法としては、特定の無機塩を
加えてオキサゾール無機塩錯化合物を形成させ、
沈殿除去する方法（英国特許第1156713号明細
書）が知られているが、この方法は特殊な薬品を
使用しなければならず、また生成した沈殿の分離
操作が厄介であるなどの欠点がある。他方におい
て、水、シアン化水素、アクリロニトリル、アセ
トン及び高沸点ニトリルなどの不純分を含む粗製
アセトニトリルにベンゼンを加えて蒸留すること
により精製する方法（特公昭45−36490号公報）
も知られているが、これは系外への逸散によるベ
ンゼンの消費、脱シアン化水素のための水酸化ア
ルカリや硫酸第一鉄の使用、精留操作の複雑性な
どにより、工業的方法として十分満足できるもの
とはいえない。
本発明者らは、粗製アセトニトリル中に含まれ
るオキサゾールをなんら薬品の添加なしに他の不
純物と同時に分離除去し、高い回収率でアセトニ
トリルを精製しうる工業的方法を開発するため
に、鋭意研究を続けた結果、粗製アセトニトリル
を一定量の水の存在下精留塔で抽出蒸留すること
により意外にもオキサゾールを他の低沸不純物と
共に非常に効率的に分離除去しうることを見出
し、この知見に基づいて本発明を完成した。
すなわち、本発明に従えばオキサゾールを含有
するアセトニトリルを水の存在下、精留塔で抽出
蒸留し、塔頂よりオキサゾールを水及び少量のア
セトニトリルと共に混合物として濃縮分離し塔下
部よりアセトニトリルを回収することを特徴とす
る精製アセトニトリルの回収方法を提供するもの
である。
本発明により処理しうる粗製アセトニトリル原
料はオキサゾール以外に水、アンモニア、アセト
ン、アクリロニトリルなどの低沸物を含んでいて
もよく、これらの不純物もオキサゾールと同時に
除去される。通常アンモキシデーシヨン工程から
副生される粗製アセトニトリルはオキサゾール
0.5〜5.0重量％含んでいる。
本発明方法においては粗アセトニトリルを水の
存在下に抽出蒸留に付すことが必要である。
本発明においては塔頂よりオキサゾールを水５
〜20重量％及び水との共沸混合物を形成する量の
アセトニトリルと共に混合物として濃縮分離し、
塔下部よりオキサゾールを含まないアセトニトリ
ルを回収する。すなわちこのような条件下ではア
セトニトリルとオキサゾールの比揮発度は非常に
大きくなり従来通常の蒸留法では完全に分離でき
なかつたアセトニトリルとオキサゾールの蒸留分
離が可能となるのである。水の含有量は、0.5〜
５重量％が好ましいが、蒸留分離のための蒸気節
減及びアセトニトリルの回収率の向上をはかるに
は１〜３重量％の範囲がより望ましい。
本発明方法は、精留塔の中間部に粗アセトニト
リルと水を別々のあるいはあらかじめ水と混合さ
れた状態で連続的に供給し、オキサゾールを少量
のアセトニトリル、水と共に混合物として頂部か
ら抜出し、塔底部から精製アセトニトリルを連続
的に回収することができる。その場合、原料中の
水分を0.5〜５重量％の範囲に調整したのち、精
留塔に供給するのが有利である。そのようにする
と、精留塔内の原料供給段付近の水分存在量が
0.5〜５重量％となり、最良の操作条件が得られ
る。
本発明で用いる蒸留塔には特に制限はないが、
通常20〜60段の多孔板式蒸留塔が用いられる。蒸
留条件としては、塔底圧力0.2〜0.3Kg／cm2、塔底
温度85〜95℃、塔頂圧力0.01〜0.03Kg／cm2、塔頂
温度75〜85℃の範囲で選択される。
このようにして、塔頂より連続的に留分を排出
させ、最下段より約１／２〜約３／４、好ましく
は約２／３の段の位置に原料を供給し、かつ塔底
部よりアセトニトリルを抜き出しながら、蒸留を
継続すれば、低沸不純分は塔頂部から蒸気として
除かれ、精製アセトニトリルが90％以上の高い回
収率で回収される。
次に添附図面に従つて、本発明方法の好適な実
施態様を説明する。
図面は、本発明方法を実施するための装置の１
例を示す説明図であり、１はシーブトレーを有す
る通常の蒸留塔で、粗製アセトニトリル原料は、
下部より２／３の位置に設けられた供給口２より
供給され、アセトニトリルは、塔底部取出口３よ
り抜き出される。この蒸留塔は塔底部の水蒸気導
入口４から吹き込まれるスチームにより塔定部85
〜95℃好ましくは87〜89℃、塔頂部75〜80℃に保
持されている。低沸不純分は塔頂部の排出口５よ
り連続的に排出され、還流受槽６を経て一部は導
管７により蒸留塔内へ還流され、残りは排出管８
により系外へ出される。
このようにして、連続的に操作することによ
り、オキサゾールを除去された精製アセトニトリ
ルが高い回収率で取出口３より抜き出される。例
えばオキサゾール含有率1.0〜2.0重量％の粗製ア
セトニトリルを処理すれば、オキサゾール含有率
がトレースないし30ppm又はそれ以下になるま
で除去することができる。また、アセトニトリル
の回収率は93〜95％と高く、この高い回収率を維
持したまま水分200〜500ppmの非常に乾燥した
アセトニトリルを得ることができる。
次に実施例により本発明をさらに詳細に説明す
る。
実施例
図に示す40段の蒸留装置の27段目における原料
供給口２から、水1.0重量％、アンモニア0.3重量
％、オキサゾール1.5重量％及びSS若干量を含む
粗製アセトニトリルを毎時600Kgの割合で供給
し、スチームによつて塔底温度90℃、塔頂温度76
℃、還流比60に維持した。このようにして、塔頂
より水12.1重量％、オキサゾール19.9重量％、そ
の他アセトニトリル64重量％を含む留出物を45.3
Kg／Ｈを得た。一方、取出口３よりアセトニトリ
ルを毎時554.5Kgで抜き出したところ、水0.02重
量％、アンモニア2ppm、オキサゾール10ppmを
含むアセトニトリルが連続的に得られた。この場
合、アセトニトリルの回収率は95.0％であつた。
参考例
シーブトレー40段及び再沸器を備えた直径500
mmの円筒状蒸留塔の下部液溜めに水3.6重量％、
オキサゾール1.5重量％及びアンモニア0.65重量
％を含む精製アセトニトリル9000Kgを仕込み、全
還流を行つた結果、留出液組成は次の分析値を示
した。
The present invention provides a method for removing oxazole from crude acetonitrile containing oxazole as an impurity to obtain pure acetonitrile, and more specifically, a method for efficiently removing oxazole and other impurities from crude acetonitrile by a single distillation operation. The present invention relates to a method for recovering pure acetonitrile. A method for producing acrylonitrile or methacrylonitrile by a gas phase contact reaction of propylene or isobutylene, oxygen, and ammonia is known, but in addition to acrylonitrile or methacrylonitrile, the reaction products obtained in this method include: Contains by-product acetonitrile and a small amount of oxazole. To separate acetonitrile and oxazole from such acrylonitrile, extractive distillation using water is usually performed, and an aqueous solution containing acetonitrile and oxazole is obtained as a by-product. By the way, in order to use this by-product acetonitrile as an industrial raw material, the oxazole in it must be removed, but since the boiling point of oxazole is close to that of acetonitrile, it is completely removed by rectification. That is extremely difficult. Conventionally, the method for removing oxazole from this by-product acetonitrile is to add a specific inorganic salt to form an oxazole inorganic salt complex compound,
A method of removing the precipitate (UK Patent No. 1156713) is known, but this method requires the use of special chemicals and has disadvantages such as the troublesome operation of separating the precipitate produced. . On the other hand, a method of purifying crude acetonitrile containing impurities such as water, hydrogen cyanide, acrylonitrile, acetone, and high-boiling nitriles by adding benzene and distilling the mixture (Japanese Patent Publication No. 36490/1983)
is also known, but this method is not suitable as an industrial method due to the consumption of benzene due to its escape from the system, the use of alkali hydroxide or ferrous sulfate for dehydrocyanation, and the complexity of the rectification operation. It cannot be said that it is satisfactory. The present inventors have conducted extensive research in order to develop an industrial method that can separate and remove oxazole contained in crude acetonitrile at the same time as other impurities without adding any chemicals, and purify acetonitrile with a high recovery rate. As a result of continued research, he unexpectedly discovered that by extractive distillation of crude acetonitrile in a rectifying column in the presence of a certain amount of water, oxazole could be separated and removed together with other low-boiling impurities very efficiently. Based on this, the present invention was completed. That is, according to the present invention, acetonitrile containing oxazole is subjected to extractive distillation in a rectification column in the presence of water, oxazole is concentrated and separated as a mixture with water and a small amount of acetonitrile from the top of the column, and acetonitrile is recovered from the bottom of the column. The present invention provides a method for recovering purified acetonitrile characterized by the following. The crude acetonitrile raw material that can be treated according to the present invention may contain low-boiling substances such as water, ammonia, acetone, and acrylonitrile in addition to oxazole, and these impurities are also removed at the same time as oxazole. Crude acetonitrile, which is usually a by-product from the ammoxidation process, is an oxazole.
Contains 0.5-5.0% by weight. In the process of the invention it is necessary to subject crude acetonitrile to extractive distillation in the presence of water. In the present invention, oxazole is added to water from the top of the column by 5
Concentrate and separate as a mixture with ~20% by weight and an amount of acetonitrile to form an azeotrope with water,
Oxazole-free acetonitrile is recovered from the bottom of the column. That is, under such conditions, the specific volatility of acetonitrile and oxazole becomes extremely high, making it possible to separate acetonitrile and oxazole by distillation, which has previously been impossible to completely separate by conventional distillation methods. Water content is 0.5~
Although 5% by weight is preferred, a range of 1 to 3% by weight is more desirable in order to save steam for distillative separation and improve the recovery rate of acetonitrile. In the method of the present invention, crude acetonitrile and water are continuously supplied to the middle part of the rectification column, either separately or mixed with water in advance, and oxazole is extracted from the top as a mixture together with a small amount of acetonitrile and water. Purified acetonitrile can be continuously recovered from. In that case, it is advantageous to adjust the water content in the raw material to a range of 0.5 to 5% by weight before feeding it to the rectification column. By doing so, the amount of water present near the raw material supply stage in the rectification column will be reduced.
0.5-5% by weight, giving the best operating conditions. Although there are no particular restrictions on the distillation column used in the present invention,
Usually, a perforated plate distillation column with 20 to 60 plates is used. The distillation conditions are selected within the range of a column bottom pressure of 0.2 to 0.3 Kg/cm 2 , a column bottom temperature of 85 to 95°C, a column top pressure of 0.01 to 0.03 Kg/cm 2 , and a column top temperature of 75 to 85°C. In this way, the fraction is continuously discharged from the top of the column, the raw material is supplied to a position about 1/2 to about 3/4, preferably about 2/3, from the bottom, and the raw material is fed from the bottom of the column. By continuing distillation while extracting acetonitrile, low-boiling impurities are removed as vapor from the top of the column, and purified acetonitrile is recovered at a high recovery rate of over 90%. Next, preferred embodiments of the method of the present invention will be described with reference to the accompanying drawings. The drawing shows one of the apparatuses for carrying out the method of the present invention.
1 is an explanatory diagram showing an example, 1 is a normal distillation column having sieve trays, and crude acetonitrile raw material is
Acetonitrile is supplied through a supply port 2 located two-thirds of the way from the bottom, and extracted through an outlet 3 at the bottom of the column. This distillation column is controlled by the steam that is blown in from the steam inlet 4 at the bottom of the column.
The temperature is maintained at ~95°C, preferably 87~89°C, and 75~80°C at the top of the column. Low-boiling impurities are continuously discharged from the outlet 5 at the top of the column, pass through a reflux receiver 6, and a portion is refluxed into the distillation column via a conduit 7, and the remainder is refluxed into the distillation column via a discharge tube 8.
is taken out of the system. By continuously operating in this manner, purified acetonitrile from which oxazole has been removed is extracted from the outlet 3 at a high recovery rate. For example, by treating crude acetonitrile with an oxazole content of 1.0 to 2.0% by weight, the oxazole content can be removed to traces to 30 ppm or less. Furthermore, the recovery rate of acetonitrile is as high as 93-95%, and very dry acetonitrile with a moisture content of 200-500 ppm can be obtained while maintaining this high recovery rate. Next, the present invention will be explained in more detail with reference to Examples. Example Crude acetonitrile containing 1.0% by weight of water, 0.3% by weight of ammonia, 1.5% by weight of oxazole, and a small amount of SS is supplied at a rate of 600 kg/hour from the raw material supply port 2 in the 27th stage of the 40-stage distillation apparatus shown in the figure. The temperature at the bottom of the column is 90℃ and the temperature at the top is 76℃ using steam.
℃ and the reflux ratio was maintained at 60. In this way, 45.3% of the distillate containing 12.1% by weight of water, 19.9% by weight of oxazole, and 64% by weight of other acetonitrile was collected from the top of the column.
Kg/H was obtained. On the other hand, when acetonitrile was extracted from the outlet 3 at a rate of 554.5 kg per hour, acetonitrile containing 0.02% by weight of water, 2 ppm of ammonia, and 10 ppm of oxazole was continuously obtained. In this case, the recovery rate of acetonitrile was 95.0%. Reference example: Diameter 500 with 40 sieve trays and reboiler
3.6% water by weight in the lower liquid reservoir of the mm cylindrical distillation column.
After charging 9000 kg of purified acetonitrile containing 1.5% by weight of oxazole and 0.65% by weight of ammonia and performing total reflux, the composition of the distillate showed the following analytical values.
【表】
次いで、留出液を毎時510Kgの割合で５時間抜
き出したのち、上部から４段目から毎時900Kgの
割合で抜き出した。２時間ごとに分析したその液
の組成は以下のとおりである。[Table] Next, the distillate was extracted at a rate of 510 kg/hour for 5 hours, and then extracted at a rate of 900 kg/hour from the fourth stage from the top. The composition of the liquid analyzed every 2 hours is as follows.
【表】
このように、オキサゾールの除去は水の共存に
より有利に行われる。[Table] Thus, the removal of oxazole is advantageously carried out by the coexistence of water.
図面は本発明方法を実施するための装置の１例
を示す説明図であり、図中符号１は蒸留塔、２は
原料供給口、３はアセトニトリル取出口、５は低
沸分排出口である。
The drawing is an explanatory view showing one example of an apparatus for carrying out the method of the present invention, and in the drawing, reference numeral 1 is a distillation column, 2 is a raw material supply port, 3 is an acetonitrile outlet, and 5 is a low boiling point discharge port. .
Claims (1)
５重量％の存在下、精留塔で抽出蒸留し、塔頂よ
りオキサゾールを水及び少量のアセトニトリルと
共に混合物として濃縮分離し、塔下部よりアセト
ニトリルを回収することを特徴とするアセトニト
リルの精製方法。 ２ 蒸留塔の下部より約２／３の段の位置に原料
を供給し連続精留をする特許請求の範囲第１項記
載の方法。 ３ 蒸留塔の供給段位置における水の存在量が
0.5〜５重量％である特許請求の範囲第２項記載
の方法。[Claims] 1. Oxazole-containing acetonitrile in water 0.5~
A method for purifying acetonitrile, which comprises performing extractive distillation in a rectification column in the presence of 5% by weight, concentrating and separating oxazole as a mixture with water and a small amount of acetonitrile from the top of the column, and recovering acetonitrile from the bottom of the column. 2. The method according to claim 1, wherein the raw material is supplied to about two-thirds of the stages from the bottom of the distillation column to carry out continuous rectification. 3 The amount of water present at the feed stage position of the distillation column is
3. The method according to claim 2, wherein the amount is 0.5 to 5% by weight.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5197979A JPS55143950A (en) | 1979-04-26 | 1979-04-26 | Purification of acetonitrile |
| US06/131,611 US4308108A (en) | 1979-03-28 | 1980-03-19 | Process for purification of crude acetonitrile |
| DE3050669A DE3050669C2 (en) | 1979-03-28 | 1980-03-25 | |
| DE3050670A DE3050670C2 (en) | 1979-03-28 | 1980-03-25 | |
| DE3050668A DE3050668C2 (en) | 1979-03-28 | 1980-03-25 | |
| DE19803011391 DE3011391A1 (en) | 1979-03-28 | 1980-03-25 | METHOD FOR PURIFYING RAW ACETONITRILE |
| IT20915/80A IT1130079B (en) | 1979-03-28 | 1980-03-26 | PROCEDURE FOR PURIFYING RAW ACETONITRILE |
| US06/289,628 US4430162A (en) | 1979-03-28 | 1981-08-03 | Process for purification of crude acetonitrile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5197979A JPS55143950A (en) | 1979-04-26 | 1979-04-26 | Purification of acetonitrile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55143950A JPS55143950A (en) | 1980-11-10 |
| JPS6154022B2 true JPS6154022B2 (en) | 1986-11-20 |
Family
ID=12901973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5197979A Granted JPS55143950A (en) | 1979-03-28 | 1979-04-26 | Purification of acetonitrile |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55143950A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2417862A (en) * | 1943-12-01 | 1947-03-25 | Us Vanadium Corp | Dehydration of acetonitrile by decantation and distillation |
| US3203975A (en) * | 1962-09-05 | 1965-08-31 | Universal Oil Prod Co | Purification of acetronitrile and propionitrile |
| US3281450A (en) * | 1963-09-27 | 1966-10-25 | Goodrich Co B F | Purification of acetonitrile |
-
1979
- 1979-04-26 JP JP5197979A patent/JPS55143950A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2417862A (en) * | 1943-12-01 | 1947-03-25 | Us Vanadium Corp | Dehydration of acetonitrile by decantation and distillation |
| US3203975A (en) * | 1962-09-05 | 1965-08-31 | Universal Oil Prod Co | Purification of acetronitrile and propionitrile |
| US3281450A (en) * | 1963-09-27 | 1966-10-25 | Goodrich Co B F | Purification of acetonitrile |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55143950A (en) | 1980-11-10 |
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