JPH0247968B2 - - Google Patents
Info
- Publication number
- JPH0247968B2 JPH0247968B2 JP59195393A JP19539384A JPH0247968B2 JP H0247968 B2 JPH0247968 B2 JP H0247968B2 JP 59195393 A JP59195393 A JP 59195393A JP 19539384 A JP19539384 A JP 19539384A JP H0247968 B2 JPH0247968 B2 JP H0247968B2
- Authority
- JP
- Japan
- Prior art keywords
- edc
- chloroprene
- dichloroethane
- concentration
- amount
- 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 - Lifetime
Links
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 claims description 78
- 238000000034 method Methods 0.000 claims description 43
- YACLQRRMGMJLJV-UHFFFAOYSA-N chloroprene Chemical compound ClC(=C)C=C YACLQRRMGMJLJV-UHFFFAOYSA-N 0.000 claims description 40
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 32
- 239000000460 chlorine Substances 0.000 claims description 32
- 229910052801 chlorine Inorganic materials 0.000 claims description 32
- 238000005660 chlorination reaction Methods 0.000 claims description 24
- 239000007788 liquid Substances 0.000 claims description 17
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 claims description 13
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 11
- 239000005977 Ethylene Substances 0.000 claims description 11
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 6
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims description 6
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 239000012530 fluid Substances 0.000 claims description 3
- 238000007664 blowing Methods 0.000 claims description 2
- 239000011541 reaction mixture Substances 0.000 claims description 2
- 239000013256 coordination polymer Substances 0.000 description 39
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 20
- 230000007423 decrease Effects 0.000 description 15
- 238000004821 distillation Methods 0.000 description 14
- 239000006227 byproduct Substances 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 6
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229930003836 cresol Natural products 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- 238000000197 pyrolysis Methods 0.000 description 3
- 238000006467 substitution reaction Methods 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 241000454273 Hirashima Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 150000001896 cresols Chemical class 0.000 description 1
- 238000006298 dechlorination reaction Methods 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910001510 metal chloride Inorganic materials 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、１，２−ジクロルエタン中に含まれ
るクロロプレンの塩素化方法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for chlorinating chloroprene contained in 1,2-dichloroethane.
（従来の技術）
１，２−ジクロルエタン（以下、EDCと略記
する）を熱分解して塩化ビニルを製造するにあた
り、反応管のコーキング防止及び副反応の抑制の
ために分解率は通常50〜60％で行なわれる。反応
混合物から塩化水素及び塩化ビニルを分離した残
りの未分解EDC中には、反応条件によつて異な
るが、通常0.2％前後のクロロプレン（以下、CP
と略記する）が含まれる。未分解EDCは精製さ
れて新しいEDCと混合して再び熱分解反応に供
されるが、CPはEDC熱分解反応を抑制したり、
製品塩化ビニルの品質を悪化させるブタジエン等
を副生するため、また重合しやすく配管または装
置を閉塞するため、その除去法については多くの
提案がなされてきた。例えば、無水塩化アルミニ
ウムを用いて接触的に処理したり、水素添加する
方法が知られているが、これらは工業的実施には
問題点が多く採用されていない。(Prior art) When producing vinyl chloride by thermally decomposing 1,2-dichloroethane (hereinafter abbreviated as EDC), the decomposition rate is usually 50 to 60 to prevent coking of the reaction tube and suppress side reactions. It is done in %. The remaining undecomposed EDC after hydrogen chloride and vinyl chloride have been separated from the reaction mixture usually contains around 0.2% chloroprene (hereinafter referred to as CP), although it varies depending on the reaction conditions.
(abbreviated as ) is included. Undecomposed EDC is purified and mixed with fresh EDC and subjected to the thermal decomposition reaction again, but CP suppresses the EDC thermal decomposition reaction,
Since butadiene and the like are produced as by-products that deteriorate the quality of the vinyl chloride product, and because they tend to polymerize and clog piping or equipment, many proposals have been made regarding methods for removing them. For example, methods of catalytic treatment using anhydrous aluminum chloride and hydrogenation are known, but these methods have many problems and have not been adopted industrially.
工業的に実施されている通常の方法としては、
CPを含むEDCを蒸留して他の低沸点成分と共に
塔頂留出物としてCPを留去する蒸留法、及び
EDC中のCPを塩素化して高沸点成分に変換した
のち蒸留分離する塩素化法が知られている。しか
し、これらの方法にも以下にのべる欠点があり満
足な方法とはいえない。 The usual method used industrially is
A distillation method in which EDC containing CP is distilled to remove CP as an overhead distillate along with other low-boiling components; and
A chlorination method is known in which CP in EDC is chlorinated to convert it into a high-boiling point component and then separated by distillation. However, these methods also have the following drawbacks and cannot be said to be satisfactory methods.
塩素化法としては、EDCを熱分解して得た分
解ガスを冷却し、凝縮した液相に未分解EDCに
対して塩素を0.01〜５％添加する方法（特開昭46
−1360）及び上記の凝縮した液相から塩化ビニル
を分離する前に熱分解炉供給EDCに対して0.01〜
１％の塩素を添加する方法（特開昭49−102605）
がある。これらの方法は副生ブタジエンの塩素化
をクロロプレンの塩素化と同時に行ないうる利点
があるが、クロロプレンを高度に塩素化させよう
とすると塩化ビニル及びEDCも塩素化され製品
の損失が大きくなる欠点がある。また、上記の凝
縮した液相から塩化ビニルを分離したのち塩素化
する方法として、エチレンを塩素化してEDCを
合成する直接塩素付加工程の反応器にCPを含む
EDCを供給して塩化鉄の存在下でエチレンの塩
素化とクロロプレンの塩素化を同時に行なう方法
（英国特許第1266676号）があるが、トリクロルエ
タン（以下、TCEと略記する）等が多量に副生
し、EDCの収率が低下する欠点がある。また、
分解工程からのEDCを別に設けた反応器で塩素
化処理し精製工程に供すると、エチレンと共に塩
素化する場合に比して副生TCEが25％以下に減
少するという提案（特公昭50−37643）があるが、
この方法によつてもまだ、かなりのTCEが副生
し、EDCの損失をきたす上に、未反応塩素が存
在するため塩素ロスが大きい。 As a chlorination method, the decomposed gas obtained by thermally decomposing EDC is cooled, and 0.01 to 5% of chlorine is added to the undecomposed EDC to the condensed liquid phase (Japanese Patent Laid-Open No. 46
−1360) and 0.01 to 0.01 to EDC supplied to the pyrolysis furnace before separating vinyl chloride from the condensed liquid phase above.
Method of adding 1% chlorine (Japanese Patent Application Laid-Open No. 102605/1984)
There is. These methods have the advantage that by-product butadiene can be chlorinated at the same time as chloroprene, but when chloroprene is highly chlorinated, vinyl chloride and EDC are also chlorinated, resulting in large product losses. be. In addition, as a method for separating vinyl chloride from the above condensed liquid phase and then chlorinating it, CP is included in the reactor for the direct chlorination process in which ethylene is chlorinated to synthesize EDC.
There is a method of simultaneously chlorinating ethylene and chloroprene in the presence of iron chloride by supplying EDC (British Patent No. 1266676), but this method involves a large amount of trichloroethane (hereinafter abbreviated as TCE), etc. The disadvantage is that the yield of EDC decreases. Also,
Proposal that if EDC from the decomposition process is chlorinated in a separate reactor and sent to the purification process, the by-product TCE will be reduced to less than 25% compared to when it is chlorinated together with ethylene. ), but
Even with this method, a considerable amount of TCE is still produced as a by-product, resulting in a loss of EDC, and the presence of unreacted chlorine causes a large chlorine loss.
特公昭59−24968には塩化水素及び塩化ビニル
を分離したのちの未分解EDC中のCPを塩素化す
るにあたり、CPに対して1.2倍モル以上の塩素を
供給して１段目は60℃以下で、２段目は60℃以上
で反応させる２段階塩素化によりCPの塩素化を
完遂し、かつ未反応塩素を残さないようにする方
法が提案されているが、副生TCEについては記
載がなく不明であるが、かなりのTCEが副生す
ると推定される。TCEの副生を抑制する方法と
して、0.01％以下のクレゾール類を塩化ビニル分
離後の未分解EDCに加えてCPを塩素化し、つい
でエチレンを加えて未反応塩素をEDCに転換し
て除去する方法（特公昭57−61331）がある。こ
の方法によれば、その実施例からTCEの副生を
大巾に減少させうることが理解できるが、クレゾ
ールは高価であり、またその取扱いが容易でない
という欠点がある。 In Japanese Patent Publication No. 59-24968, when chlorinating CP in undecomposed EDC after separating hydrogen chloride and vinyl chloride, 1.2 times the mole or more of chlorine to CP is supplied and the first stage is kept at 60℃ or less. A method has been proposed in which the second stage is a two-step chlorination reaction at 60°C or higher to complete the chlorination of CP without leaving any unreacted chlorine, but there is no mention of the by-product TCE. It is estimated that a considerable amount of TCE is produced as a by-product, although it is not clear whether this is the case. A method for suppressing TCE by-products is to add 0.01% or less of cresols to undecomposed EDC after vinyl chloride separation to chlorinate CP, and then add ethylene to convert unreacted chlorine to EDC and remove it. (Special Publication No. 57-61331). Although it can be seen from the examples that this method can greatly reduce the amount of TCE by-product, it has the drawbacks that cresol is expensive and that it is not easy to handle.
一方、蒸留法については、Mcpherson、R.W.、
HYDROCARBON PROCESSING 58(3)75
（1979）に記載されている２、３の工業プロセス
の工程図から理解できるように、熱分解工程から
の未分解EDCを脱水後のオキシ塩素化工程及び
直接塩素付加工程からのEDCと混合して蒸留し
他の低沸点成分と共にCPを塔頂から留去してい
る。しかし、平島、PETROTECH、１(3)284
（1978）に記載されているように、EDC中のCPが
５〜10重量％に濃縮されると重合をはじめ、ゴム
状物質が蒸留塔トレイやコンデンサ表面に付着し
たり閉塞の原因となる。従つて、塔頂成分中のク
ロロプレン濃度は５％以下にとどめる必要があ
り、多量のEDCを塔頂から留出させるためEDC
ロスの原因となる。 On the other hand, regarding the distillation method, Mcpherson, R.W.
HYDROCARBON PROCESSING 58 (3)75
(1979), undecomposed EDC from the pyrolysis step is mixed with EDC from the post-dehydration oxychlorination step and the direct chlorination step. The CP is distilled off from the top of the column along with other low-boiling components. However, Hirashima, PETROTECH, 1 (3)284
(1978), when CP in EDC is concentrated to 5 to 10% by weight, it begins to polymerize and a rubbery substance adheres to the distillation column tray and condenser surface, causing blockage. Therefore, the concentration of chloroprene in the top component must be kept below 5%, and in order to distill a large amount of EDC from the top, EDC
It causes loss.
以上のごとく、塩素化法及び蒸留法いずれにお
いても損失が多く、原料エチレン、塩素に対する
EDC又は塩化ビニルの収率が低下すると共に、
精製するためのエネルギー使用量が増加するため
に経済的に不利となる。 As mentioned above, both the chlorination method and the distillation method have large losses, and
As the yield of EDC or vinyl chloride decreases,
It is economically disadvantageous because the amount of energy used for refining increases.
（発明が解決しようとする問題点）
本発明者等は従来法の欠点を克服すべく鋭意検
討を行なつた結果、本発明をなすに至つた。本発
明は前記の蒸留法と塩素化法とを組合せたものと
みることもできるが、蒸留法によつて濃縮された
CPを塩素化すると、CPの塩素化と共にEDCの置
換反応が生じ、多量のTCEが生成する。この現
象は、西脇他、化学工学33(7)613（1969）に記載さ
れている現象と同様に考えることができる。即ち
エチレンの塩素化の場合、金属塩化物の不存在下
においてはエチレンの存在が光と同程度の置換促
進作用を有するが、CPの塩素化の場合において
もCPの存在がEDCの置換塩素化を促進する。
EDC中のCP濃度が大きい程EDCの置換塩素化も
促進される。以下にのべる実施例に示したように
この現象は実験によつて確かめられた。置換塩素
化は塩化鉄、酸素またはクレゾールのような抑制
剤の添加によつて抑制しうることが知られている
が、取扱いの繁雑さ、後工程への影響、経済性を
考慮するとそれらの抑制剤を用いない方が望まし
い。(Problems to be Solved by the Invention) The present inventors have conducted intensive studies to overcome the drawbacks of conventional methods, and as a result, have accomplished the present invention. Although the present invention can be seen as a combination of the above-mentioned distillation method and chlorination method,
When CP is chlorinated, a substitution reaction of EDC occurs along with CP chlorination, producing a large amount of TCE. This phenomenon can be considered similar to the phenomenon described by Nishiwaki et al., Chemical Engineering 33 (7) 613 (1969). In other words, in the case of chlorination of ethylene, the presence of ethylene has the same effect of promoting substitution as light in the absence of metal chlorides, but in the case of chlorination of CP, the presence of CP also promotes substitutional chlorination of EDC. promote.
The higher the CP concentration in EDC, the more the substitutional chlorination of EDC is promoted. This phenomenon was confirmed through experiments as shown in the examples below. It is known that substitutional chlorination can be suppressed by adding inhibitors such as iron chloride, oxygen, or cresol, but such suppression is difficult considering the complexity of handling, impact on subsequent processes, and economic efficiency. It is preferable not to use agents.
蒸留による濃縮を緩和し、蒸留塔頂部から留出
するEDC中のCP濃度を下げると置換塩素化はあ
る程合抑制されるが、まだかなりの置換反応が生
じることはさけられない。たとえば、特公昭57−
61331の実施例２によると、CPを1650ppm含む未
分解EDCを塩素化した場合、残存塩素460ppmの
ときCPは20ppmにまで減少したが、TCEは
6ppmから2000ppmに増加したと記載されている。
即ち、蒸留による濃縮を全く行なわない場合にお
いてもCPの減少量１に対してTCEの増加量は
1.22に達したことになる。同公報実施例１ではｏ
−クレゾールを10ppm添加するとCPの減少量１
に対してTCE増加量は0.10に減少したことが示さ
れている。 Although substitutional chlorination can be suppressed to some extent by relaxing the concentration caused by distillation and lowering the CP concentration in EDC distilled from the top of the distillation column, it is still inevitable that a considerable amount of substitution reaction will occur. For example, the
According to Example 2 of 61331, when undecomposed EDC containing 1650 ppm of CP was chlorinated, CP decreased to 20 ppm when the residual chlorine was 460 ppm, but TCE decreased.
It is stated that the amount increased from 6ppm to 2000ppm.
In other words, even when no concentration by distillation is performed, the amount of increase in TCE for each decrease in CP is
This means that it has reached 1.22. In Example 1 of the same publication, o
- When adding 10 ppm of cresol, CP decreases by 1
It is shown that the TCE increase amount decreased to 0.10.
（問題点を解決するための手段及び作用効果）
本発明者はそれらの問題点を解決すべく鋭意検
討した結果、EDC中に濃縮されたCPを塩素化す
るにあたり、塩素化処理後の粗EDCの一部を分
取して塩素化器入口へ循環使用し、塩素供給部位
でのEDC中のCPの濃度を低濃度に、好ましくは
0.5％以下の状態で塩素化することにより抑制剤
を添加することなくTCEの生成をおさえてCPを
除去することができることを確認した。とくに、
適当な循環量を選ぶことにより、常にCP減少量
１に対してTCE増加量を0.1以下に抑制しうるこ
とを見出し本発明をなすに至つた。以下に、本発
明を詳細に説明する。(Means and Effects for Solving the Problems) As a result of intensive studies to solve these problems, the present inventor found that when chlorinating CP concentrated in EDC, the crude EDC after chlorination treatment is A portion of the CP is collected and recycled to the chlorinator inlet to reduce the concentration of CP in the EDC at the chlorine supply site, preferably
It was confirmed that by chlorinating at 0.5% or less, it is possible to suppress the generation of TCE and remove CP without adding an inhibitor. especially,
The present inventors have discovered that by selecting an appropriate circulation rate, it is possible to always suppress the increase in TCE to 0.1 or less for every decrease in CP of 1. The present invention will be explained in detail below.
本発明でいうCPは２−クロル−ブタジエン−
１，３及びクロル−ブタジエン１，３の混合物で
ある。また、CPを含むEDCとしては、熱分解後
のEDCであればよいが、効果的に行うためには
塩化水素および塩化ビニルを除去した後のもの、
特にCPを分離するための蒸留塔の塔頂液に適用
するのが最も適している。例えば次の如くであ
る。EDCを分解率50〜60％で分解すると、塩化
水素及び塩化ビニルを分離したあとの未分解
EDC中にはCPが0.15〜0.30％含まれる。この未分
解EDCを蒸留塔に供給し塔頂よりCPを１〜３％
含むEDCを留出させる。塔底からは略純粋の
EDCが取出され、他の工程からの精製EDCと混
合して熱分解用原料として使用することができ
る。CPを含む塔頂留分は塩素化器に供給される。
塩素化器出口液の一部を分取して塩素化器入口に
循環し、上記CPを含む塔頂留分と混合したのち
塩素化反応を行なう。循環液の混合比率は混合後
のEDC中のCP濃度が好ましくは0.5重量％以下に
なるようにする。この濃度が高いとTCEの副生
量が増加する。循環液の量は、塔頂留分のCP濃
度と液量によつて異るが、例えば、2.3％のCPを
含む塔頂留分が２T/Hのとき７T/H以上、好ま
しくは14〜20T/H循環するとよい。循環の手段
としては塩素ガスによるリフト、サーモサイフオ
ン、ポンプ等を用いることができる。反応温度は
50℃以下がよく、反応によつて温度が上昇するの
で冷却した循環液を用いても50℃以下に保つ。冷
却しないと温度が上昇しTCEの副生量が増す。
塩素化反応器は鋼製の反応器が使用されるが、そ
の材質には特に制限はなく鉄製でもよい。反応器
の内部にはEDCと塩素との接触をよくするため
にラシヒリングを充填するとよい。塩素は電解塩
素を使用する場合、通常１％前後の酸素が含まれ
るが、そのまま使用できる。塩素の供給量はCP
の絶対量によるが、通常塩素化器出口における
EDC中の残存塩素濃度が300〜500ppmになるよ
うに調整するのが好ましい。残存塩素濃度が高い
とTCEの副生量がます。 CP in the present invention is 2-chloro-butadiene-
1,3 and chloro-butadiene 1,3. In addition, EDC containing CP may be EDC after thermal decomposition, but in order to be effective, it is necessary to use EDC after removing hydrogen chloride and vinyl chloride.
In particular, it is most suitable for application to the top liquid of a distillation column for separating CP. For example, as follows. When EDC is decomposed at a decomposition rate of 50 to 60%, the undecomposed residue after hydrogen chloride and vinyl chloride are separated
EDC contains 0.15-0.30% CP. This undecomposed EDC is fed to a distillation column, and 1 to 3% CP is extracted from the top of the column.
The EDC containing it is distilled out. Almost pure from the bottom of the tower
The EDC can be removed and mixed with purified EDC from other processes and used as feedstock for pyrolysis. The overhead fraction containing CP is fed to the chlorinator.
A portion of the chlorinator outlet liquid is collected and circulated to the chlorinator inlet, where it is mixed with the overhead fraction containing the CP and subjected to a chlorination reaction. The mixing ratio of the circulating fluid is such that the CP concentration in the EDC after mixing is preferably 0.5% by weight or less. When this concentration is high, the amount of TCE by-product increases. The amount of circulating liquid varies depending on the CP concentration and liquid volume of the overhead fraction, but for example, when the overhead fraction containing 2.3% CP is 2 T/H, the amount of circulating liquid is 7 T/H or more, preferably 14~ It is recommended to circulate 20T/H. As a means of circulation, a lift using chlorine gas, a thermosiphon, a pump, etc. can be used. The reaction temperature is
It is best to keep the temperature below 50°C, and since the temperature rises during the reaction, the temperature should be kept below 50°C even if a cooled circulating fluid is used. If not cooled, the temperature will rise and the amount of TCE by-product will increase.
A steel reactor is used as the chlorination reactor, but the material thereof is not particularly limited and may be made of iron. It is recommended to fill the inside of the reactor with a Raschig ring to improve contact between EDC and chlorine. When using electrolytic chlorine, it usually contains around 1% oxygen, but it can be used as is. The amount of chlorine supplied is CP
Depending on the absolute amount of
It is preferable to adjust the residual chlorine concentration in EDC to 300 to 500 ppm. If the residual chlorine concentration is high, the amount of TCE by-product will increase.
塩素化器の出口液は一部を循環用に分取したあ
と、残りを後処理工程に送る。後処理工程ではア
ルカリ水溶液で直接洗浄したのち蒸留して精製
EDCを回収することができるが、残存塩素量に
見合う量のエチレンを吹きこんで残存塩素を
EDCに転換したのち、アルカリ水溶液で洗浄し、
蒸留して精製EDCを回収することができる。こ
の脱塩素化反応器は塩素化反応器と同様のものを
用いることができる。あるいは、塩素化器の出口
液に残存塩素量に見合うエチレンを供給して残存
塩素をEDCに転換したのち一部を分取して塩素
化化器入口へ循環し、残りを後処理工程に送り、
洗浄、蒸留して精製EDCを回収することができ
る。 A portion of the chlorinator's outlet liquid is separated for circulation, and the remainder is sent to a post-treatment process. In the post-processing process, the product is directly washed with an alkaline aqueous solution and then purified by distillation.
EDC can be recovered, but the remaining chlorine must be removed by blowing in an amount of ethylene that is commensurate with the amount of remaining chlorine.
After converting to EDC, washing with alkaline aqueous solution,
Purified EDC can be recovered by distillation. This dechlorination reactor can be the same as the chlorination reactor. Alternatively, after converting the remaining chlorine into EDC by supplying ethylene corresponding to the amount of residual chlorine to the outlet liquid of the chlorinator, a portion is separated and circulated to the chlorinator inlet, and the remainder is sent to the post-treatment process. ,
Purified EDC can be recovered by washing and distillation.
以上にのべた方法より、以下に示す実施例から
理解できるように、外部から特別に置換反応抑制
剤を加えることなく、CP減少量１に対してTCE
増加量を0.1以下に抑制することができる。この
理由については特に究明していないが、先に示し
た先行文献のデータを考えあわせると、単にCP
濃度を希釈して下げただけで達成される抑制効果
以上に効果が出ており、塩素化処理液を循環する
ことによつてクロロプレン塩素化物等の反応生成
物のいずれかが抑制効果を示しているかもしれな
い。 From the method described above, as can be understood from the examples shown below, TCE is
The amount of increase can be suppressed to 0.1 or less. The reason for this has not been specifically investigated, but considering the data in the previous literature shown above, it seems that CP
The inhibitory effect was greater than that achieved simply by diluting and lowering the concentration, and by circulating the chlorinated solution, any of the reaction products such as chloroprene chloride showed an inhibitory effect. There may be.
（実施例） 以下に実施例によつて具体的に説明する。(Example) This will be specifically explained below using examples.
実施例 １
EDCを熱分解し塩化水素及び塩化ビニルを分
離したあとの未分解EDCを精留し、塔頂よりク
ロロプレン2.3％を含むEDC2T/Hを得た。この
EDCを、塩素化処理後のEDCの一部を分取して
塩素化器入口に循環する循環EDCと混合して塩
素化器に供給した。循環EDCは冷却器を通して
35℃とし、循環量を20T/Hとした。循環EDCと
混合したあとのEDC中のクロロプレン濃度は0.21
％であつた。塩素化器は内径300mm、高さ2900mm
の鉄製円筒状であり内部にラシヒリングを充填し
た。この反応器の底部から上記EDCと電解塩素
ガスを供給した。塩素化器出口におけるEDC中
の残存塩素濃度が300ppmになるように塩素供給
量を調節した。塩素化器出口液22T/Hのうち20
Ｔ／Ｈを分取して循環用に使用し、残り２T/Hを
精製工程に供給し他の工程からのEDCと共に蒸
留しEDCを回収した。Example 1 After thermally decomposing EDC and separating hydrogen chloride and vinyl chloride, undecomposed EDC was rectified to obtain EDC2T/H containing 2.3% chloroprene from the top of the column. this
EDC was supplied to the chlorinator after being mixed with circulating EDC, which was separated from a portion of the EDC after the chlorination treatment and circulated to the inlet of the chlorinator. Circulating EDC through cooler
The temperature was 35°C and the circulation rate was 20T/H. Chloroprene concentration in EDC after mixing with circulating EDC is 0.21
It was %. The chlorinator has an inner diameter of 300mm and a height of 2900mm.
It has a cylindrical shape made of iron and is filled with a Raschig ring. The EDC and electrolytic chlorine gas were supplied from the bottom of this reactor. The amount of chlorine supplied was adjusted so that the residual chlorine concentration in EDC at the outlet of the chlorinator was 300 ppm. 20 out of 22T/H of chlorinator outlet liquid
T/H was fractionated and used for circulation, and the remaining 2 T/H was supplied to the purification process and distilled together with EDC from other processes to recover EDC.
反応が定常状態に達したあとの塩素化器出口に
おけるEDCを分析したところ、クロロプレンは
0.01％以下、トリクロルエタンは0.09％であつ
た。クロロプレン減少量１に対してトリクロルエ
タン増加量は0.04であつた。 Analysis of EDC at the outlet of the chlorinator after the reaction reached a steady state revealed that chloroprene was
It was less than 0.01%, and trichloroethane was 0.09%. The amount of increase in trichloroethane was 0.04 for the amount of decrease in chloroprene of 1.
実施例 ２
循環量を14T/Hとした以外は実施例１と同様
にした。塩素化入口のクロロプレン濃度は0.29％
であり、塩素化器出口のクロロプレン濃度は0.01
％以下、トリクロルエタン濃度は0.15％であつ
た。クロロプレン減少量１に対してトリクロルエ
タン増加量は0.07であつた。Example 2 The same procedure as Example 1 was carried out except that the circulation rate was 14 T/H. Chloroprene concentration at chlorination inlet is 0.29%
and the chloroprene concentration at the chlorinator outlet is 0.01
%, the trichloroethane concentration was 0.15%. The amount of increase in trichloroethane was 0.07 for the amount of decrease in chloroprene of 1.
実施例 ３
循環量を７T/Hとした以外は実施例１と同様
に行つた。塩素化器入口のクロロプレン濃度は
0.50％であり、塩素化器出口のクロロプレン濃度
は0.01％以下トリクロルエタン濃度は0.24％であ
つた。クロロプレン減少量１に対しトリクロルエ
タン増加量は0.10であつた。Example 3 The same procedure as in Example 1 was carried out except that the circulation amount was 7 T/H. The chloroprene concentration at the chlorinator inlet is
The concentration of chloroprene at the outlet of the chlorinator was 0.01% or less, and the concentration of trichloroethane was 0.24%. The amount of increase in trichloroethane was 0.10 for the amount of decrease in chloroprene of 1.
実施例 ４
循環EDCを45℃に冷却した以外は実施例２と
同様にして行なつた。塩素化器出口におけるクロ
ロプレン濃度は0.01％以下、トリクロルエタン濃
度は0.22％であつた。クロロプレン減少量１に対
してトリクロルエタン増加量は0.1であつた。Example 4 Example 2 was repeated except that the circulating EDC was cooled to 45°C. The chloroprene concentration at the chlorinator outlet was less than 0.01%, and the trichloroethane concentration was 0.22%. The amount of increase in trichloroethane was 0.1 for the amount of decrease in chloroprene of 1.
比較例 １
循環を全く行なわなかつた以外は実施例１と同
様にして行なつた。この場合、塩素化器出口の温
度は50〜60℃に上昇し反応が不安定となり、定常
状状態にするのは困難であつた。塩素化器出口に
おけるクロロプレン濃度は0.01％以下であつた
が、トリクロルエタンは1.4％に達し、他に高沸
点物が２〜2.3％生成した。クロロプレン減少量
１に対してトリクロルエタン増加量は0.6であつ
た。Comparative Example 1 The same procedure as in Example 1 was carried out except that no circulation was performed. In this case, the temperature at the outlet of the chlorinator rose to 50 to 60°C, making the reaction unstable and making it difficult to maintain a steady state. The concentration of chloroprene at the outlet of the chlorinator was less than 0.01%, but trichloroethane reached 1.4%, and other high-boiling substances were produced in an amount of 2 to 2.3%. The amount of increase in trichloroethane was 0.6 for the amount of decrease in chloroprene of 1.
実施例 ５
塩素化出口における残存塩素濃度を440ppmと
した以外は実施例１と同様にした。塩素化器出口
のクロロプレン濃度は0.01％以下、トリクロルエ
タン濃度は0.15％であつた。クロロプレン減少量
１に対してトリクロルエタン増加量は0.07であつ
た。Example 5 The same procedure as Example 1 was carried out except that the residual chlorine concentration at the chlorination outlet was 440 ppm. The chloroprene concentration at the outlet of the chlorinator was less than 0.01%, and the trichloroethane concentration was 0.15%. The amount of increase in trichloroethane was 0.07 for the amount of decrease in chloroprene of 1.
実施例 ６
塩素化器出口における残存塩素濃度を1360ppm
とした以外は実施例１と同様にして行なつた。塩
素化器出口のクロロプレン濃度は0.01％以下、ト
リクロルエタン濃度は0.24％であつた。クロロプ
レン減少量１に対してトリクロルエタン増加量は
0.1であつた。Example 6 Residual chlorine concentration at the chlorinator outlet to 1360ppm
The procedure was carried out in the same manner as in Example 1 except for the following. The concentration of chloroprene at the outlet of the chlorinator was less than 0.01%, and the concentration of trichloroethane was 0.24%. The amount of increase in trichloroethane for the amount of decrease in chloroprene is
It was 0.1.
実施例 ７
実施例１において、塩素化器出口液中の残存塩
素濃度を440ppmになるように塩素供給量を調節
し、塩素化器出口液を塩素化器と同様の大きさの
ラシヒリングを充填した脱塩素化器の頂部に供給
し底部よりエチレンガスを供給した。脱塩素化器
の出口液22T/Hのうち20T/Hを分取して塩素化
器の入口に循環し残り２T/Hを精製工程に送つ
た。Example 7 In Example 1, the chlorine supply amount was adjusted so that the residual chlorine concentration in the chlorinator outlet liquid was 440 ppm, and the chlorinator outlet liquid was filled with a Raschig ring of the same size as the chlorinator. Ethylene gas was supplied to the top of the dechlorinator and from the bottom. Of the 22 T/H of the outlet liquid from the dechlorinator, 20 T/H was fractionated and circulated to the inlet of the chlorinator, and the remaining 2 T/H was sent to the purification process.
脱塩素化器出口におけるクロロプレン濃度は
0.01％以下、トリクロルエタン濃度は0.18％、残
存塩素濃度は0.01％以下であつた。クロロプレン
減少量１に対してトリクロルエタンの増加量は
0.08であつた。 The chloroprene concentration at the dechlorinator outlet is
The trichloroethane concentration was 0.18%, and the residual chlorine concentration was 0.01% or less. The amount of increase in trichloroethane for each decrease in chloroprene is
It was 0.08.
実施例 ８
実施例１において、塩素化器出口液中の塩素濃
度を440ppmとし、塩素化器出口液22T/Hのうち
20T/Hを分取して塩素化器入口に循環し残り２
Ｔ／Ｈを実施例７の脱塩素化器に供給した。脱塩
素化器入口の残存塩素量に見合う量のエチレンを
供給したところ脱塩素化器出口における残存塩素
濃度は0.005％以下、クロロプレン濃度は0.01％
以下、トリクロルエタンは0.17％であつた。クロ
ロプレン減少量１に対するトリクロルエタン増加
量は0.07であつた。Example 8 In Example 1, the chlorine concentration in the chlorinator outlet liquid was 440 ppm, and the chlorine concentration in the chlorinator outlet liquid was 22T/H.
20T/H is separated and circulated to the chlorinator inlet and the remaining 2
T/H was fed to the dechlorinator of Example 7. When ethylene was supplied in an amount commensurate with the amount of residual chlorine at the dechlorinator inlet, the residual chlorine concentration at the dechlorinator outlet was less than 0.005%, and the chloroprene concentration was 0.01%.
Below, trichloroethane was 0.17%. The increase in trichloroethane per decrease in chloroprene of 1 was 0.07.
本発明の効果を一層明確に示すために、実施例
１〜８、比較例１及び引用した先行技術に示され
ている実施例、比較例のデータを第１図に示す。 In order to more clearly demonstrate the effects of the present invention, data of Examples 1 to 8, Comparative Example 1, and the Examples and Comparative Examples shown in the cited prior art are shown in FIG.
横軸は循環EDCと混合したあとの塩素化器入
口のEDC中のクロロプレン濃度であり、縦軸は
クロロプレンの減少量に対するトリクロルエタン
の増加量の比率である。 The horizontal axis is the concentration of chloroprene in the EDC at the inlet of the chlorinator after mixing with the circulating EDC, and the vertical axis is the ratio of the increase in trichloroethane to the decrease in chloroprene.
第１図は、本発明の効果を先行技術と対比して
示したグラフである。
FIG. 1 is a graph showing the effects of the present invention in comparison with the prior art.
Claims (1)
合物から塩化水素及び塩化ビニルを分離した残り
の未分解１，２−ジクロルエタン中のクロロプレ
ンを塩素化するにあたり、未分解１，２−ジクロ
ルエタンを蒸留してクロロプレンを１，２−ジク
ロルエタンの一部と共に塔頂に留去し、ついでこ
のクロロプレンを含有する１，２−ジクロルエタ
ンからなる塔頂液に、このクロロプレンを含有す
る１，２−ジクロルエタンを塩素化処理した液の
一部を分取し循環して混合したのち、塩素化する
ことを特徴とする１，２−ジクロルエタン中に含
まれるクロロプレンの塩素化方法。 ２ 循環液と混合することによつて、塩素供給部
位における１，２−ジクロルエタン中のクロロプ
レン濃度を0.5重量％以下にすることを特徴とす
る特許請求の範囲第１項記載の方法。 ３ 循環する液が、１，２−ジクロルエタン中に
含まれるクロロプレンを塩素化し、ついでエチレ
ンを吹込むことにより残存塩素を処理したあと分
取した液である特許請求の範囲第１項または第２
項記載の方法。 ４ 塩素化を50℃以下で行なう特許請求の範囲第
１項記載の方法。 ５ 塩素化後の残存塩素濃度が300ppm〜500ppm
である特許請求の範囲第１項または第２項記載の
方法。[Scope of Claims] 1 In chlorinating chloroprene in undecomposed 1,2-dichloroethane remaining after thermally decomposing 1,2-dichloroethane and separating hydrogen chloride and vinyl chloride from the reaction mixture, undecomposed 1, 2-dichloroethane is distilled to remove chloroprene together with a portion of 1,2-dichloroethane at the top of the column, and then the 1,2-dichloroethane containing chloroprene is added to the top liquid consisting of 1,2-dichloroethane containing chloroprene. A method for chlorinating chloroprene contained in 1,2-dichloroethane, which comprises separating a portion of a liquid obtained by chlorinating 2-dichloroethane, circulating it, mixing it, and then chlorinating it. 2. The method according to claim 1, wherein the chloroprene concentration in 1,2-dichloroethane at the chlorine supply site is reduced to 0.5% by weight or less by mixing with the circulating fluid. 3. Claim 1 or 2, wherein the circulating liquid is a liquid separated after chlorinating chloroprene contained in 1,2-dichloroethane and then treating residual chlorine by blowing in ethylene.
The method described in section. 4. The method according to claim 1, wherein the chlorination is carried out at 50°C or lower. 5 Residual chlorine concentration after chlorination is 300ppm to 500ppm
The method according to claim 1 or 2, wherein:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19539384A JPS6172728A (en) | 1984-09-17 | 1984-09-17 | Chlorination of chloroprene in 1,2-dichloroethane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19539384A JPS6172728A (en) | 1984-09-17 | 1984-09-17 | Chlorination of chloroprene in 1,2-dichloroethane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6172728A JPS6172728A (en) | 1986-04-14 |
| JPH0247968B2 true JPH0247968B2 (en) | 1990-10-23 |
Family
ID=16340397
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19539384A Granted JPS6172728A (en) | 1984-09-17 | 1984-09-17 | Chlorination of chloroprene in 1,2-dichloroethane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6172728A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8026400B2 (en) * | 2007-12-19 | 2011-09-27 | Dupont Performance Elastomers Llc | Process for production of 2,3-dichlorobutadiene-1,3 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5037643A (en) * | 1973-08-07 | 1975-04-08 |
-
1984
- 1984-09-17 JP JP19539384A patent/JPS6172728A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5037643A (en) * | 1973-08-07 | 1975-04-08 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6172728A (en) | 1986-04-14 |
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