CA1043359A - Dehydrochlorination of 1,2-dichloroethane - Google Patents
Dehydrochlorination of 1,2-dichloroethaneInfo
- Publication number
- CA1043359A CA1043359A CA218,969A CA218969A CA1043359A CA 1043359 A CA1043359 A CA 1043359A CA 218969 A CA218969 A CA 218969A CA 1043359 A CA1043359 A CA 1043359A
- Authority
- CA
- Canada
- Prior art keywords
- chloride
- ethane
- dichloroethane
- effected
- multivalent metal
- 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
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 238000007033 dehydrochlorination reaction Methods 0.000 title claims description 35
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 claims abstract description 36
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 claims abstract description 32
- RCJVRSBWZCNNQT-UHFFFAOYSA-N dichloridooxygen Chemical compound ClOCl RCJVRSBWZCNNQT-UHFFFAOYSA-N 0.000 claims abstract description 22
- 150000003839 salts Chemical class 0.000 claims abstract description 18
- 229910001510 metal chloride Inorganic materials 0.000 claims abstract description 17
- 229910052751 metal Inorganic materials 0.000 claims abstract description 15
- 239000002184 metal Substances 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims description 25
- 230000008569 process Effects 0.000 claims description 25
- 239000000155 melt Substances 0.000 claims description 24
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical group Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 claims description 20
- 238000006243 chemical reaction Methods 0.000 claims description 17
- 239000000203 mixture Substances 0.000 claims description 14
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 11
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims description 11
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims description 11
- 238000002844 melting Methods 0.000 claims description 11
- 230000008018 melting Effects 0.000 claims description 11
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 8
- 239000005977 Ethylene Substances 0.000 claims description 8
- 239000010949 copper Substances 0.000 claims description 8
- 229910052802 copper Inorganic materials 0.000 claims description 7
- 230000000994 depressogenic effect Effects 0.000 claims description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical group ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 claims description 6
- 239000003112 inhibitor Substances 0.000 claims description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 5
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 5
- 150000008280 chlorinated hydrocarbons Chemical class 0.000 claims description 5
- 239000000460 chlorine Substances 0.000 claims description 5
- 229910052801 chlorine Inorganic materials 0.000 claims description 5
- UBOXGVDOUJQMTN-UHFFFAOYSA-N trichloroethylene Natural products ClCC(Cl)Cl UBOXGVDOUJQMTN-UHFFFAOYSA-N 0.000 claims description 5
- 150000001805 chlorine compounds Chemical class 0.000 claims description 4
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 3
- 229910001514 alkali metal chloride Inorganic materials 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 239000011651 chromium Substances 0.000 claims description 3
- 235000012721 chromium Nutrition 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- 229910001385 heavy metal Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims 2
- 229940107218 chromium Drugs 0.000 claims 2
- 229910052748 manganese Inorganic materials 0.000 claims 2
- 239000011572 manganese Substances 0.000 claims 2
- 238000007038 hydrochlorination reaction Methods 0.000 claims 1
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 10
- 238000005660 chlorination reaction Methods 0.000 description 8
- 239000011833 salt mixture Substances 0.000 description 8
- 229960003280 cupric chloride Drugs 0.000 description 7
- 239000005752 Copper oxychloride Substances 0.000 description 5
- HKMOPYJWSFRURD-UHFFFAOYSA-N chloro hypochlorite;copper Chemical compound [Cu].ClOCl HKMOPYJWSFRURD-UHFFFAOYSA-N 0.000 description 5
- 235000011164 potassium chloride Nutrition 0.000 description 5
- 239000001103 potassium chloride Substances 0.000 description 5
- HRYZWHHZPQKTII-UHFFFAOYSA-N chloroethane Chemical compound CCCl HRYZWHHZPQKTII-UHFFFAOYSA-N 0.000 description 4
- 229960003750 ethyl chloride Drugs 0.000 description 4
- -1 trichloroethylene Chemical class 0.000 description 3
- QPFMBZIOSGYJDE-UHFFFAOYSA-N 1,1,2,2-tetrachloroethane Chemical compound ClC(Cl)C(Cl)Cl QPFMBZIOSGYJDE-UHFFFAOYSA-N 0.000 description 2
- SCYULBFZEHDVBN-UHFFFAOYSA-N 1,1-Dichloroethane Chemical compound CC(Cl)Cl SCYULBFZEHDVBN-UHFFFAOYSA-N 0.000 description 2
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 2
- 229940045803 cuprous chloride Drugs 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- 241000331231 Amorphocerini gen. n. 1 DAD-2008 Species 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000007806 chemical reaction intermediate Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical class [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 235000007686 potassium Nutrition 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229960003975 potassium Drugs 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- GBECUEIQVRDUKB-UHFFFAOYSA-M thallium monochloride Chemical compound [Tl]Cl GBECUEIQVRDUKB-UHFFFAOYSA-M 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C21/00—Acyclic unsaturated compounds containing halogen atoms
- C07C21/02—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds
- C07C21/04—Chloro-alkenes
- C07C21/06—Vinyl chloride
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/25—Preparation of halogenated hydrocarbons by splitting-off hydrogen halides from halogenated hydrocarbons
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
1,2-dichloroethane is dehydrochlorinated by direct contact with a molten salt including the higher and lower valent forms of a multivalent metal chloride and generally also the oxychloride of the metal with ethane being present to increase selectivity to vinyl chloride.
1,2-dichloroethane is dehydrochlorinated by direct contact with a molten salt including the higher and lower valent forms of a multivalent metal chloride and generally also the oxychloride of the metal with ethane being present to increase selectivity to vinyl chloride.
Description
F/2523i-E~IO:cs ~043;~59 DEHYOR(~CHI.ORINATION OF 1, 2 DIC]-ILOROETJ~ANE
This invention relates to the production of vinyl chloride, and more particularly, to improved dehydrochlorination of 1, 2 -dichlo-roethane to vinyl chloride.
A process for dehydrochlorinating 1,2-dichloroethane to vinyl chloride by the use of molten salts is known in the art. In accordance with such a process, 1, 2 -dichloroethane is dehydrochlorinated by direct contact with a melt containing the higher and lower valent forms of a multivalent metal chloride, with the meU optionally including the corresponding oxychloride, at high conversion and higher selectivity.
I0 It has been recently found that in the case where the melt includes the oxychloride, the selectivity to vinyl chloride is lower than the case in which the melt does not include the oxychloride. Furthermore, in many cases, the 1, 2-dichloroethane employed as feed is recovered from the chlorination effluent produced in an overall process for the production of vinyl chloride, as described in British Patent Specification No.
1,213,202. The recovered 1,2-dichloroethane may include unsaturated chlorinated hydrocarbons, such as trichloroethylene, which may function as dehydrochlorination inhibitors and thereby decrease select-Lvity to vinyl chloride.
In accordance with the present invention, 1, 2 -dichloro -ethane is dehydrochlorinated by direct contact with a molten salt con-taining a multivalent metal chloride in its higher and lower valence state the contacting being effected in the presence of ethane in that the presence of ethane has been found to improve the overall selectivity to vinyl chl-)ride.
.~ ' More particularly, the ethane is prescnt in an amount to provide a weight ratio of ethane to 1,2-dichloroethane from 0.0l:l to 0.15:1, and preferably from 0. 0l5:l to O. lO:l. The use of ethane in amounts lower than those hereinabove described does not provide the desired improvement in selectivity to vinyl chloride, and the use of ethane in amounts greater than those hereinabove described results in a decrease in vinyl chloride selectivity and/or 1, 2 -dichloroethane convers ion.
Although the present invention is not bound by any theory, it is believed that the addition of ethane functions to reduce substitutive chlorination of dichloroethane which results in an increase selectivity to vinyl chloride. It is further believed that the addition of ethane functions, in part, to inhibit the increase of cupric chloride concentra-tion of the melt through the dehydrochlorination reaction zone which I5 could result from interaction between any oxychloride present in the melt and hydrogen chloride released during the dehydrochlorination.
The melts employed in the dehydrochlorination include the higher and lower valent forms of a chloride of a multivalent metal; i, e., a metal having more than one positive valence state, such as manga-nese, iron, copper, cobalt and chromium, preferably copper. In the cases of higher melting multivalent metal chlorides, such as copper chlorides, a metal salt melting point depressant which is non-volatile and resistant to the action of oxygen at the process conditions, such as a chloride of a univalent metal; i. e., a metal having only one positive valence state, is added to the multivalent metal chloride to form a molten salt mixture having a reduced melting point. The univalent metal chlorides, are preferably alkali metal chlorides, such as potas-sium and lithium chlorides in particular, but it is to be understood that other metal chlorides and mixtures thereof, such as the heavy metal chlorides; i. e., heavier than copper, of Groups I, II, III and IV of the Periodic Table; e. g., zinc, silver and thallium chloride, may also be employed. The metal chloride meLting point depressant is added in an amount sufficient to maintain the salt mixture as a melt at the reaction temperatures, and is generally added in an amount sufficient to adjust the melting point of the molten salt mixture to a temperature of below 500DF. In the case of a salt mixture of copper chlorides and potassium chloride, the composition of the melt ranges between 20~1C to 40~c, pre-ferably 30~1c, by weight, potassium chloride, wUh the remainder being copper chlorides. It is to be understood, however, that in some cases the catalyst melt may have a melting point higher than 500F, provided the catalyst remains in the form of the melt throughout the processing steps. It is further to be understood that the melt may contain a mix-ture of multivalent metal chlorides or other reaction promoters. It is also to be understood that in some cases, metal chloride may be maintained in molten form without a melting point depressant.
In accordance with a preferred embodiment, the molten salt used in the dehydrochlorination further includes the oxychloride of the multivalent metal in that the oxychloride reacts with the hydro-gen chloride liberated during the dehydrochlorination, as represented by the following equation using copper oxychloride as a representative
This invention relates to the production of vinyl chloride, and more particularly, to improved dehydrochlorination of 1, 2 -dichlo-roethane to vinyl chloride.
A process for dehydrochlorinating 1,2-dichloroethane to vinyl chloride by the use of molten salts is known in the art. In accordance with such a process, 1, 2 -dichloroethane is dehydrochlorinated by direct contact with a melt containing the higher and lower valent forms of a multivalent metal chloride, with the meU optionally including the corresponding oxychloride, at high conversion and higher selectivity.
I0 It has been recently found that in the case where the melt includes the oxychloride, the selectivity to vinyl chloride is lower than the case in which the melt does not include the oxychloride. Furthermore, in many cases, the 1, 2-dichloroethane employed as feed is recovered from the chlorination effluent produced in an overall process for the production of vinyl chloride, as described in British Patent Specification No.
1,213,202. The recovered 1,2-dichloroethane may include unsaturated chlorinated hydrocarbons, such as trichloroethylene, which may function as dehydrochlorination inhibitors and thereby decrease select-Lvity to vinyl chloride.
In accordance with the present invention, 1, 2 -dichloro -ethane is dehydrochlorinated by direct contact with a molten salt con-taining a multivalent metal chloride in its higher and lower valence state the contacting being effected in the presence of ethane in that the presence of ethane has been found to improve the overall selectivity to vinyl chl-)ride.
.~ ' More particularly, the ethane is prescnt in an amount to provide a weight ratio of ethane to 1,2-dichloroethane from 0.0l:l to 0.15:1, and preferably from 0. 0l5:l to O. lO:l. The use of ethane in amounts lower than those hereinabove described does not provide the desired improvement in selectivity to vinyl chloride, and the use of ethane in amounts greater than those hereinabove described results in a decrease in vinyl chloride selectivity and/or 1, 2 -dichloroethane convers ion.
Although the present invention is not bound by any theory, it is believed that the addition of ethane functions to reduce substitutive chlorination of dichloroethane which results in an increase selectivity to vinyl chloride. It is further believed that the addition of ethane functions, in part, to inhibit the increase of cupric chloride concentra-tion of the melt through the dehydrochlorination reaction zone which I5 could result from interaction between any oxychloride present in the melt and hydrogen chloride released during the dehydrochlorination.
The melts employed in the dehydrochlorination include the higher and lower valent forms of a chloride of a multivalent metal; i, e., a metal having more than one positive valence state, such as manga-nese, iron, copper, cobalt and chromium, preferably copper. In the cases of higher melting multivalent metal chlorides, such as copper chlorides, a metal salt melting point depressant which is non-volatile and resistant to the action of oxygen at the process conditions, such as a chloride of a univalent metal; i. e., a metal having only one positive valence state, is added to the multivalent metal chloride to form a molten salt mixture having a reduced melting point. The univalent metal chlorides, are preferably alkali metal chlorides, such as potas-sium and lithium chlorides in particular, but it is to be understood that other metal chlorides and mixtures thereof, such as the heavy metal chlorides; i. e., heavier than copper, of Groups I, II, III and IV of the Periodic Table; e. g., zinc, silver and thallium chloride, may also be employed. The metal chloride meLting point depressant is added in an amount sufficient to maintain the salt mixture as a melt at the reaction temperatures, and is generally added in an amount sufficient to adjust the melting point of the molten salt mixture to a temperature of below 500DF. In the case of a salt mixture of copper chlorides and potassium chloride, the composition of the melt ranges between 20~1C to 40~c, pre-ferably 30~1c, by weight, potassium chloride, wUh the remainder being copper chlorides. It is to be understood, however, that in some cases the catalyst melt may have a melting point higher than 500F, provided the catalyst remains in the form of the melt throughout the processing steps. It is further to be understood that the melt may contain a mix-ture of multivalent metal chlorides or other reaction promoters. It is also to be understood that in some cases, metal chloride may be maintained in molten form without a melting point depressant.
In accordance with a preferred embodiment, the molten salt used in the dehydrochlorination further includes the oxychloride of the multivalent metal in that the oxychloride reacts with the hydro-gen chloride liberated during the dehydrochlorination, as represented by the following equation using copper oxychloride as a representative
2 5 oxychloride:
(1) Cu O. C~ C12 ~ IICl ~ 2 Cu ~'~2 + lI2O
104;~;~S9 In this manner, the effluent will have reduced amounts of hydrogen chloride (the effluent includes equilibrium amounts of hydrogen chloride~.
The oxychloride is preferably present in an amount to react with essen-tially all of the hydrogen chloride produced in the dehydrochlorination.
The ethane which is present during the dehydrochlorination reaction may be chlorinated in part or in its entirety to chlorinated hydrocarbons (vinyl chloride, ethyl chloride, dichloroethanes, etc. ) as a result of the chlorinating abilUy of the molten salt.
The dehydrochlorination is generally effected at tempera-tures from 700F to 1200F, preferably from 750F to 1000F, although the temperatures could be as low as 575F, and at pressures from 1 to 20 atmospheres. The contacting of feed and melt is generally effec-ted in a countercurrent fashion, preferably with the feed as a continuous vapor phase, at residence times from 1 to 60 seconds, although longer residence times may be employed.
The dehydrochlorination process of the present invention is preferably employed as part of an overall process for producing vinyl chloride from ethane and/or ethylene by the use of molten salts.
More particularly, ethane and/or ethylene is contacted with a melt containing the multivalent metal chloride in its higher and lower valence state, with the molten salt mixture preferably also containing the oxy-chloride of the metal, with the contacting preferably also being effected with hydrogen chloride and/or chlorine to produce an effluent containing vinyl chtoride and 1,2-dichloroethane, The vinyl chloride is recovered as product and the 1, 2-dichloroethane is dehydrochlorinated by direct contact u~ 'h the molten salt containing the higher and lower valent ~043359 metal chloride, and preferably also including the oxychloride of the multivalent metal, in the presence of ethane as hereinabove described, to produce a dehydrochlorination effluent containing vinyl chloride.
In accordance with a preferreù embodiment of the present invention, a molten salt mixture containing copper chlorides and a melting point depressant (preferably in an amount from 20 to 40 weight percent of the melt with the melting point depressant being preferably potassium chloride, with the remainder of the melt being copper chlo-rides) is contacted in a first reaction zone with molecular oxygen to produce copper oxychloride. The cupric chloride content of the melt is generally at least 16~c, by weight, of the melt, and generally from 18~c to 50~c, by weight, in order to provide sufficient cupric chloride for the subsequent chlorination and dehydrochlorination reactions. It is to be understood, however, that lower amounts of cupric chloride may also be employed by increasing salt circulation rates and residence times. As a result of the various reactions which occur during the chlorination and dehydrochlorination steps, the cupric chloride content of the melt does not significantly vary through the various reaction zones. The molecular oxygen is preferably introduced in an amount, and at a rate, to provide a molten salt mixture containing from 0. 5~1c to 5. 5~c, preferably from 15~ to 3~c, all by weight, of copper oxychloride.
It is to be understood that minor amounts of chlorine and/or hydrogen chloride could also be introduced into the first reaction zone, but in accordance with this preferred embodiment, the major portion of the chlorine and/or hydrogen chloride is added to the chlorination zone.
The m?~ten salt mixture, now containing copper oxychLoridc, is circulated to a second reaction zone (chlorination zone) wherein the molten salt is contacted with ethane and/or ethylene, preferably ethane, and chlorine and/or hydrogen chloride as fresh feed, in addition to recycle unconverted ethane (if employed as feed) and recycle ethyl chloride and unreacted ethylene or that generated as reaction intermediate. The recycle, may also include l,l-dichloro-ethane and/or dichloroethylene.
The effluent from the second zone includes vinyl chloride, 1,2-dichloroethane, ethyl chloride, ethane, ethylene, and heavier chlorinated hydrocarbons; for example, one or more of the following:
trichloroethylene, tetrachloroethylene, trichloroethanes and tetra-- chloroethane. The effluent also includes water vapor and equilibrium amounts of hydrogen chloride.
The reaction effluent is passed to a separation and reco-very zone wherein various components are recovered. Ethyl chloride, ethane and ethylene are recovered for ultimate cor~ersion to vinyl chloride. The recovered 1,2-dichloroethane is introduced into a dehy-drochlorination zone (third reaction %one) wherein the 1,2-dichloro-ethane is contacted with molten salt from the first (the salt includes oxychloride?, the second zone or both zones in the presence of ethane to effect dehydrochlorination of 1,2-dichloroethane to vinyl chloride.
As a result of the chlorinating ability of the molten salt all or a por-tion of the ethane is converted to chlorinated products, as dcscribed with reference to the second reaction zone, The effluent from the dehydrochlorination reaction zone is introduccd into a separation and recovery zcne ~D recover vinyl chloride r eaction product and other 10~3;~S9 components for ultimate utilization thereof for the production of vinyl chlor ide .
The ethane utilized in tlle dehydrochlorination reaction zone may be either fresh feed or recycle ethane recovered from the chlorination (second reaction zone) effluent or a combination thereof.
It is to be understood that the source of ethane is immaterial to the present invention, provided the ethane is employed for the dehydro-chlorination as hereinabove described.
The chlorination in the presence of the melt (second reaction zone) may be effected at conditions, as hereinabove described with reference to the dehydrochlorination in the presence of molten saU. The production of oxychloride is generally effected at temper-atures of 600DF to 900DF, although higher temperatures may be employed. The preferred oxychloride production temperature is from 750F to 870F, The overall process for producing vinyl chloride from ethane and/or ethylene by the use of molten salts, including dehydro-chlorination of 1, 2-dichloroethane by the use of molten salts, is described in British Patent Specification No. 1, 213, 202 . The present invention is an improvement with respect to such a process in that dehydrochlorination selectivity to vinyl chloride is improved by use of ethane in the dehydrochlorination zone, as hereinabove described.
Although the invention is particularly applicable to an embodiment in which oxychloride is present in the melt employed in the dehydrochlorination reaction zone, the present invention may also be employed in cases where there is no oxyctlloride present in lV43;~S9 that the 1,2-dichLo!~oethane feed to the dehydrochlorination reaction zone, in SUCil a case, -may include a àehydrochlorination inhibitor, such as trichloroethylene, The addition of ethane to the dehydrochlo-rination reaction zone, as hereinabove described, minimizes the adverse effect on selectivity to vinyl chloride which could result from the presence of a dehydrochlorination inhibitor.
The invention will be further described with respect to the following example.
EXAMPLE I
A molten salt comprised of 17.1 wt. ~c cupric chloride; 51. 8 wt.~c cuprous chloride; 0.2 wt.~c copper oxychloride; and 30.9 wt.%
potassium chloride is countercurrently contacted with a feed comprised of 90. 6 mole ~c of a l, 2-dichloroethane blend and 9. 4 mole percent of ethane, at a temperature of 849~F and a residence time of 8. 7 seccnds.
The 1,2-dichloroethane blend has the following composition:
DCE blend mole ~'lc 1, l, l C2H3Cl3 0. 6 CCl4 l' 3 l,2 C2H4Cl2 78. 3 C2HCl3 11.1 1,1, 2 C2 H3C13 4' 5 C2C14 4. 2 100. 0 The vinyl chloride selectivity is 90. 4 mole percent, and the l, 2-dichloroethane conversion is 80 mole percent, notwithstanding the presence of oxychloride intlle melt and the use of a high propor~ion of trichloroetllylene in the feed which would be expected to inhibit dehydrochlorination.
EXAMP LE II
~ molten salt comprised of 16. 5 wt. ~c cupric chloride;
52. 6 wt. ~ cuprous chloride; 0. 2 wt. '~c copper oxychloride; and 30. 7 wt. ~lc potassium chloride is countercurrently contacted with a feed comprised of 84. 5~c mole ~c of the 1, 2-dichloroethane blend of Example I and 15. 5 mole percent of ethane, at a temperature of 850F and a residence time of 7 seconds. The vinyl chloride selectivity is 91. 8 mole percent, and the 1, 2-dichloroethane conversion is 79. 7 mole per cent .
The present invention is particularly advantageous in that 1 2-dichloroethane can be dehydrochlorinated to vinyl chloride at corv ersions in excess of 70 percent while maintaining selectivity to vinyl chloride of at least about 80 percent, (and generally selectivities of greater than 90~c can be achieved), notwithstanding the presence of oxychloride in the melt and/or the presence of a dehydrochlorination inhibitor, such as trichloroethylene, in the 1, 2 -dichloroethane feed.
(1) Cu O. C~ C12 ~ IICl ~ 2 Cu ~'~2 + lI2O
104;~;~S9 In this manner, the effluent will have reduced amounts of hydrogen chloride (the effluent includes equilibrium amounts of hydrogen chloride~.
The oxychloride is preferably present in an amount to react with essen-tially all of the hydrogen chloride produced in the dehydrochlorination.
The ethane which is present during the dehydrochlorination reaction may be chlorinated in part or in its entirety to chlorinated hydrocarbons (vinyl chloride, ethyl chloride, dichloroethanes, etc. ) as a result of the chlorinating abilUy of the molten salt.
The dehydrochlorination is generally effected at tempera-tures from 700F to 1200F, preferably from 750F to 1000F, although the temperatures could be as low as 575F, and at pressures from 1 to 20 atmospheres. The contacting of feed and melt is generally effec-ted in a countercurrent fashion, preferably with the feed as a continuous vapor phase, at residence times from 1 to 60 seconds, although longer residence times may be employed.
The dehydrochlorination process of the present invention is preferably employed as part of an overall process for producing vinyl chloride from ethane and/or ethylene by the use of molten salts.
More particularly, ethane and/or ethylene is contacted with a melt containing the multivalent metal chloride in its higher and lower valence state, with the molten salt mixture preferably also containing the oxy-chloride of the metal, with the contacting preferably also being effected with hydrogen chloride and/or chlorine to produce an effluent containing vinyl chtoride and 1,2-dichloroethane, The vinyl chloride is recovered as product and the 1, 2-dichloroethane is dehydrochlorinated by direct contact u~ 'h the molten salt containing the higher and lower valent ~043359 metal chloride, and preferably also including the oxychloride of the multivalent metal, in the presence of ethane as hereinabove described, to produce a dehydrochlorination effluent containing vinyl chloride.
In accordance with a preferreù embodiment of the present invention, a molten salt mixture containing copper chlorides and a melting point depressant (preferably in an amount from 20 to 40 weight percent of the melt with the melting point depressant being preferably potassium chloride, with the remainder of the melt being copper chlo-rides) is contacted in a first reaction zone with molecular oxygen to produce copper oxychloride. The cupric chloride content of the melt is generally at least 16~c, by weight, of the melt, and generally from 18~c to 50~c, by weight, in order to provide sufficient cupric chloride for the subsequent chlorination and dehydrochlorination reactions. It is to be understood, however, that lower amounts of cupric chloride may also be employed by increasing salt circulation rates and residence times. As a result of the various reactions which occur during the chlorination and dehydrochlorination steps, the cupric chloride content of the melt does not significantly vary through the various reaction zones. The molecular oxygen is preferably introduced in an amount, and at a rate, to provide a molten salt mixture containing from 0. 5~1c to 5. 5~c, preferably from 15~ to 3~c, all by weight, of copper oxychloride.
It is to be understood that minor amounts of chlorine and/or hydrogen chloride could also be introduced into the first reaction zone, but in accordance with this preferred embodiment, the major portion of the chlorine and/or hydrogen chloride is added to the chlorination zone.
The m?~ten salt mixture, now containing copper oxychLoridc, is circulated to a second reaction zone (chlorination zone) wherein the molten salt is contacted with ethane and/or ethylene, preferably ethane, and chlorine and/or hydrogen chloride as fresh feed, in addition to recycle unconverted ethane (if employed as feed) and recycle ethyl chloride and unreacted ethylene or that generated as reaction intermediate. The recycle, may also include l,l-dichloro-ethane and/or dichloroethylene.
The effluent from the second zone includes vinyl chloride, 1,2-dichloroethane, ethyl chloride, ethane, ethylene, and heavier chlorinated hydrocarbons; for example, one or more of the following:
trichloroethylene, tetrachloroethylene, trichloroethanes and tetra-- chloroethane. The effluent also includes water vapor and equilibrium amounts of hydrogen chloride.
The reaction effluent is passed to a separation and reco-very zone wherein various components are recovered. Ethyl chloride, ethane and ethylene are recovered for ultimate cor~ersion to vinyl chloride. The recovered 1,2-dichloroethane is introduced into a dehy-drochlorination zone (third reaction %one) wherein the 1,2-dichloro-ethane is contacted with molten salt from the first (the salt includes oxychloride?, the second zone or both zones in the presence of ethane to effect dehydrochlorination of 1,2-dichloroethane to vinyl chloride.
As a result of the chlorinating ability of the molten salt all or a por-tion of the ethane is converted to chlorinated products, as dcscribed with reference to the second reaction zone, The effluent from the dehydrochlorination reaction zone is introduccd into a separation and recovery zcne ~D recover vinyl chloride r eaction product and other 10~3;~S9 components for ultimate utilization thereof for the production of vinyl chlor ide .
The ethane utilized in tlle dehydrochlorination reaction zone may be either fresh feed or recycle ethane recovered from the chlorination (second reaction zone) effluent or a combination thereof.
It is to be understood that the source of ethane is immaterial to the present invention, provided the ethane is employed for the dehydro-chlorination as hereinabove described.
The chlorination in the presence of the melt (second reaction zone) may be effected at conditions, as hereinabove described with reference to the dehydrochlorination in the presence of molten saU. The production of oxychloride is generally effected at temper-atures of 600DF to 900DF, although higher temperatures may be employed. The preferred oxychloride production temperature is from 750F to 870F, The overall process for producing vinyl chloride from ethane and/or ethylene by the use of molten salts, including dehydro-chlorination of 1, 2-dichloroethane by the use of molten salts, is described in British Patent Specification No. 1, 213, 202 . The present invention is an improvement with respect to such a process in that dehydrochlorination selectivity to vinyl chloride is improved by use of ethane in the dehydrochlorination zone, as hereinabove described.
Although the invention is particularly applicable to an embodiment in which oxychloride is present in the melt employed in the dehydrochlorination reaction zone, the present invention may also be employed in cases where there is no oxyctlloride present in lV43;~S9 that the 1,2-dichLo!~oethane feed to the dehydrochlorination reaction zone, in SUCil a case, -may include a àehydrochlorination inhibitor, such as trichloroethylene, The addition of ethane to the dehydrochlo-rination reaction zone, as hereinabove described, minimizes the adverse effect on selectivity to vinyl chloride which could result from the presence of a dehydrochlorination inhibitor.
The invention will be further described with respect to the following example.
EXAMPLE I
A molten salt comprised of 17.1 wt. ~c cupric chloride; 51. 8 wt.~c cuprous chloride; 0.2 wt.~c copper oxychloride; and 30.9 wt.%
potassium chloride is countercurrently contacted with a feed comprised of 90. 6 mole ~c of a l, 2-dichloroethane blend and 9. 4 mole percent of ethane, at a temperature of 849~F and a residence time of 8. 7 seccnds.
The 1,2-dichloroethane blend has the following composition:
DCE blend mole ~'lc 1, l, l C2H3Cl3 0. 6 CCl4 l' 3 l,2 C2H4Cl2 78. 3 C2HCl3 11.1 1,1, 2 C2 H3C13 4' 5 C2C14 4. 2 100. 0 The vinyl chloride selectivity is 90. 4 mole percent, and the l, 2-dichloroethane conversion is 80 mole percent, notwithstanding the presence of oxychloride intlle melt and the use of a high propor~ion of trichloroetllylene in the feed which would be expected to inhibit dehydrochlorination.
EXAMP LE II
~ molten salt comprised of 16. 5 wt. ~c cupric chloride;
52. 6 wt. ~ cuprous chloride; 0. 2 wt. '~c copper oxychloride; and 30. 7 wt. ~lc potassium chloride is countercurrently contacted with a feed comprised of 84. 5~c mole ~c of the 1, 2-dichloroethane blend of Example I and 15. 5 mole percent of ethane, at a temperature of 850F and a residence time of 7 seconds. The vinyl chloride selectivity is 91. 8 mole percent, and the 1, 2-dichloroethane conversion is 79. 7 mole per cent .
The present invention is particularly advantageous in that 1 2-dichloroethane can be dehydrochlorinated to vinyl chloride at corv ersions in excess of 70 percent while maintaining selectivity to vinyl chloride of at least about 80 percent, (and generally selectivities of greater than 90~c can be achieved), notwithstanding the presence of oxychloride in the melt and/or the presence of a dehydrochlorination inhibitor, such as trichloroethylene, in the 1, 2 -dichloroethane feed.
Claims (17)
1. A process for producing vinyl chloride by dehydrochlorina-ting 1,2-dichloroethane, comprising:
dehydrochlorinating 1,2-dichloroethane to vinyl chloride by direct contact with a molten salt containing a multivalent metal chloride in its higher and lower valence state, and the oxychloride of the multivalent metal, said contacting being effected in the presence of ethane in an amount to provide an ethane to 1,2-dichloroethane weight ratio from 0. 01:1 to 0.15:1.
dehydrochlorinating 1,2-dichloroethane to vinyl chloride by direct contact with a molten salt containing a multivalent metal chloride in its higher and lower valence state, and the oxychloride of the multivalent metal, said contacting being effected in the presence of ethane in an amount to provide an ethane to 1,2-dichloroethane weight ratio from 0. 01:1 to 0.15:1.
2. The process of Claim 1 wherein the melt further contains the oxychloride of the multivalent metal.
3. The process of Claim 2 wherein the muUivalent metal chloride is selected from the group consisting of the chlorides of copper, chromium, cobalt, iron, manganese and mixtures thereof.
4. The process of Claim 2 wherein the multivalent metal chloride is copper chloride.
5. The process of Claim 4 wherein the contacting is effected at a temperature from 700°F to 1200°F,
6. The process of Claim 3, 4, or 5 wherein the melt further includes, as a melting point depressant, an alkali metal chloride, a heavy metal chloride or mixtures thereof.
7. The process of Claim 3, 4, or 5 wherein the ethane to 1,2-dichloroethane weight ratio is from .015:1 to 0.10:1.
8. The process of Claim 3, 4, or 5 wherein the dehydro-chlorination is effected in the presence of an unsaturated chlorinated hydrocarbon dehydrochlorination inhibitor,
9, The process of Claim 3, 4, or 5 wherein the dehydrochlo-rination is effected in the presence of trichloroethylene.
10. A process for producing vinyl chloride comprising:
(a) contacting in a first reaction zone ethane, ethylene or mixtures thereof with chlorine, hydrogen chloride or mixtures there-of and a melt comprising the higher and lower valent chlorides of a multivalent metal and the oxychloride of the multivalent metal to produce a first effluent containing vinyl chloride and 1,2-dichloro-ethane;
(b) recovering vinyl chloride and 1,2-dichloroethane from the first effluent; and (c) dehydrochlorinating recovered 1,2-dichloroethane to vinyl chloride by direct contact with a melt containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the metal, said contacting being effected in the presence of ethane in an amount to provide an ethane to 1,2-dichloroethane weight ratio from 0.01:1 to 0.15:1.
(a) contacting in a first reaction zone ethane, ethylene or mixtures thereof with chlorine, hydrogen chloride or mixtures there-of and a melt comprising the higher and lower valent chlorides of a multivalent metal and the oxychloride of the multivalent metal to produce a first effluent containing vinyl chloride and 1,2-dichloro-ethane;
(b) recovering vinyl chloride and 1,2-dichloroethane from the first effluent; and (c) dehydrochlorinating recovered 1,2-dichloroethane to vinyl chloride by direct contact with a melt containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the metal, said contacting being effected in the presence of ethane in an amount to provide an ethane to 1,2-dichloroethane weight ratio from 0.01:1 to 0.15:1.
11. The process of Claim 10 wherein the multivalent metal chloride employed in steps (a) and (c) is a chloride of copper, chro-mium, cobalt, iron, manganese or mixtures thereof.
12. The process of Claim 10 wherein the multivalent metal chloride is copper chloride.
13. The process of Claim 12 wherein the contacting of steps (a) and (c) is effected at a temperature from 700°F to 1200°F
14. The process of Claim 11, 12, or 13 wherein the melt further includes, as a melting point depressant, an alkali metal chloride, a heavy metal chloride or mixtures thereof.
15. The process of Claim 11, 12, or 13 wherein the ethane to 1,2-dichloroethane weight ratio is from . 015:1 to 0.10:1.
16. The process of Claim 11, 12, or 13 wherein the dehydro-chlorination is effected in the presence of an unsaturated chlorinated hydrocarbon de hydrochlor ination inhibitor.
17. The process of Claim 11, 12 or 13 wherein the dehydrochlo-rination is effected in the presence of trichloroethylene.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US43798574A | 1974-01-30 | 1974-01-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1043359A true CA1043359A (en) | 1978-11-28 |
Family
ID=23738752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA218,969A Expired CA1043359A (en) | 1974-01-30 | 1975-01-29 | Dehydrochlorination of 1,2-dichloroethane |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS598244B2 (en) |
| AR (1) | AR203062A1 (en) |
| BE (1) | BE824948A (en) |
| BR (1) | BR7500570A (en) |
| CA (1) | CA1043359A (en) |
| DE (1) | DE2502335A1 (en) |
| ES (1) | ES434238A1 (en) |
| FR (1) | FR2259075B1 (en) |
| GB (1) | GB1442117A (en) |
| IT (1) | IT1031224B (en) |
| NL (1) | NL7501027A (en) |
| SE (1) | SE7500942L (en) |
| TR (1) | TR18490A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0015665B1 (en) * | 1979-03-02 | 1982-09-01 | Imperial Chemical Industries Plc | Manufacture of vinyl chloride |
| JPH0350936U (en) * | 1989-09-26 | 1991-05-17 | ||
| FR2897482B1 (en) | 2006-02-10 | 2010-10-29 | Cogema | DEVICE FOR TRANSPORTING ELECTRICITY WITH HIGH CURRENT AND HIGH FREQUENCY |
-
1975
- 1975-01-21 DE DE19752502335 patent/DE2502335A1/en not_active Withdrawn
- 1975-01-27 TR TR1849075A patent/TR18490A/en unknown
- 1975-01-28 JP JP1105975A patent/JPS598244B2/en not_active Expired
- 1975-01-28 IT IT1967675A patent/IT1031224B/en active
- 1975-01-28 GB GB367175A patent/GB1442117A/en not_active Expired
- 1975-01-29 SE SE7500942A patent/SE7500942L/xx not_active Application Discontinuation
- 1975-01-29 AR AR25745675A patent/AR203062A1/en active
- 1975-01-29 BR BR7500570A patent/BR7500570A/en unknown
- 1975-01-29 CA CA218,969A patent/CA1043359A/en not_active Expired
- 1975-01-29 BE BE152854A patent/BE824948A/en not_active IP Right Cessation
- 1975-01-29 NL NL7501027A patent/NL7501027A/en not_active Application Discontinuation
- 1975-01-29 ES ES434238A patent/ES434238A1/en not_active Expired
- 1975-01-30 FR FR7502963A patent/FR2259075B1/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ES434238A1 (en) | 1976-12-16 |
| GB1442117A (en) | 1976-07-07 |
| JPS598244B2 (en) | 1984-02-23 |
| BR7500570A (en) | 1975-11-11 |
| BE824948A (en) | 1975-05-15 |
| SE7500942L (en) | 1975-07-31 |
| NL7501027A (en) | 1975-08-01 |
| TR18490A (en) | 1977-02-24 |
| DE2502335A1 (en) | 1975-07-31 |
| FR2259075A1 (en) | 1975-08-22 |
| FR2259075B1 (en) | 1978-06-23 |
| JPS50106908A (en) | 1975-08-22 |
| IT1031224B (en) | 1979-04-30 |
| AR203062A1 (en) | 1975-08-08 |
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