CA1071238A - Purging tars and carbon from chlorinated hydrocarbon effluent - Google Patents
Purging tars and carbon from chlorinated hydrocarbon effluentInfo
- Publication number
- CA1071238A CA1071238A CA231,406A CA231406A CA1071238A CA 1071238 A CA1071238 A CA 1071238A CA 231406 A CA231406 A CA 231406A CA 1071238 A CA1071238 A CA 1071238A
- Authority
- CA
- Canada
- Prior art keywords
- chlorinated hydrocarbon
- tars
- carbon
- effluent
- chlorinated
- 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
- 150000008280 chlorinated hydrocarbons Chemical class 0.000 title claims abstract description 54
- 239000011269 tar Substances 0.000 title claims abstract description 43
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 40
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 40
- 238000010926 purge Methods 0.000 title description 3
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical class Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 claims abstract description 8
- RCJVRSBWZCNNQT-UHFFFAOYSA-N dichloridooxygen Chemical compound ClOCl RCJVRSBWZCNNQT-UHFFFAOYSA-N 0.000 claims abstract description 8
- 230000000694 effects Effects 0.000 claims abstract description 6
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 239000002184 metal Substances 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 14
- 238000010791 quenching Methods 0.000 claims description 10
- 150000001805 chlorine compounds Chemical class 0.000 claims description 9
- 239000011833 salt mixture Substances 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 8
- 229930195733 hydrocarbon Natural products 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 239000004215 Carbon black (E152) Substances 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 claims description 4
- -1 hydrocarbon chlorinated hydrocarbon Chemical class 0.000 claims description 4
- 239000005752 Copper oxychloride Substances 0.000 claims description 3
- HKMOPYJWSFRURD-UHFFFAOYSA-N chloro hypochlorite;copper Chemical compound [Cu].ClOCl HKMOPYJWSFRURD-UHFFFAOYSA-N 0.000 claims description 3
- 229960003280 cupric chloride Drugs 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910021591 Copper(I) chloride Inorganic materials 0.000 claims description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 2
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 claims description 2
- 229940045803 cuprous chloride Drugs 0.000 claims description 2
- 229910052748 manganese Inorganic materials 0.000 claims description 2
- 239000011572 manganese Substances 0.000 claims description 2
- 230000000171 quenching effect Effects 0.000 claims description 2
- 229910000684 Cobalt-chrome Inorganic materials 0.000 claims 1
- WAIPAZQMEIHHTJ-UHFFFAOYSA-N [Cr].[Co] Chemical compound [Cr].[Co] WAIPAZQMEIHHTJ-UHFFFAOYSA-N 0.000 claims 1
- 239000010952 cobalt-chrome Substances 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 abstract description 15
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 10
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 abstract description 7
- 238000002485 combustion reaction Methods 0.000 abstract description 2
- 238000005660 chlorination reaction Methods 0.000 description 21
- 150000003839 salts Chemical class 0.000 description 15
- 230000003647 oxidation Effects 0.000 description 11
- 238000007254 oxidation reaction Methods 0.000 description 11
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 10
- 239000007789 gas Substances 0.000 description 9
- 239000000460 chlorine Substances 0.000 description 8
- 238000007033 dehydrochlorination reaction Methods 0.000 description 8
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 8
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 8
- 238000000926 separation method Methods 0.000 description 8
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 7
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 7
- 229910052801 chlorine Inorganic materials 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 238000011084 recovery Methods 0.000 description 7
- 150000002430 hydrocarbons Chemical class 0.000 description 6
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 5
- 239000000155 melt Substances 0.000 description 5
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M potassium chloride Inorganic materials [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 5
- SCYULBFZEHDVBN-UHFFFAOYSA-N 1,1-Dichloroethane Chemical compound CC(Cl)Cl SCYULBFZEHDVBN-UHFFFAOYSA-N 0.000 description 4
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 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
- KFUSEUYYWQURPO-UHFFFAOYSA-N 1,2-dichloroethene Chemical class ClC=CCl KFUSEUYYWQURPO-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 2
- HRYZWHHZPQKTII-UHFFFAOYSA-N chloroethane Chemical compound CCCl HRYZWHHZPQKTII-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 229960003750 ethyl chloride Drugs 0.000 description 2
- 230000009969 flowable effect Effects 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229910001510 metal chloride Inorganic materials 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 235000011164 potassium chloride Nutrition 0.000 description 2
- 239000001103 potassium chloride Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-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
- 229910001514 alkali metal chloride Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910002090 carbon oxide Inorganic materials 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 238000007038 hydrochlorination reaction Methods 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
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001590 oxidative effect Effects 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
- 229960002816 potassium chloride Drugs 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- GBECUEIQVRDUKB-UHFFFAOYSA-M thallium monochloride Chemical compound [Tl]Cl GBECUEIQVRDUKB-UHFFFAOYSA-M 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
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/38—Separation; Purification; Stabilisation; Use of additives
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
.
An effluent containing chlorinated hydrocarbons and tar, withdrawn from a reactor employing molten copper chlorides and oxychloride, is quenched to separate carbon and tars, and the separated carbon and tars introduced into the reactor to effect combustion thereof. The reaction is preferably directed to the production of vinyl chloride or chlorinated methanes.
.
An effluent containing chlorinated hydrocarbons and tar, withdrawn from a reactor employing molten copper chlorides and oxychloride, is quenched to separate carbon and tars, and the separated carbon and tars introduced into the reactor to effect combustion thereof. The reaction is preferably directed to the production of vinyl chloride or chlorinated methanes.
Description
107~Z38 PU~GING OF TARS AND CARBON FROM
CHLORINATED HYDROCARBON EFFLUENT
This invention relates to the treatment of an effluent containing chlorinated hydrocarbons, and more particu-larly, to a new and improved process for purging tars and carbon from an effluent containing chlorinated hydrocarbons.
In the chlorination of a hydrocarbon, or partially chlorinated hydrocarbon, the chlorination effluent generally includes tars and carbon which are carried into the separation and recovery system for separating and recovering the various components of the chlorination effluent. In such processes, the tar and carbon materials may cause difficulties in the separation and recovery system. In addition, processing steps must be effected to purge the system of such tars and carbon.
In accordance with the present invention, tars and carbon are separated from an effluent containing chlorinated hydrocarbons, withdrawn from a melt chlorination and/or dehydro-chlorination reaction zone, and the separated tars and carbon are directly contacted with a molten mixture, containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the metal to effect oxidation of the tars and carbon. In this manner, the tars and carbon are effectively purged from the system without being passed through the separa-tion and recovery system for recovering the various chlorinated hydrocarbons.
Thus, in accordance with the present teachings, an improved process is provided for producing a chlorinated hydrocarbon by contacting in a chlorinated hydrocarbon production zone a member selected from the group consisting of a hydrocarbon, chlorinated hydrocarbon and mixtures thereof with a molten salt mixture containing the higher and lower valent chlorides of a multivalent metal selected from the group consisting of copper, ~ -2- ~
~1 , iron, cobalt, chromium and manganese and the oxychloride of the multivalent metals. The process comprises withdrawing from the chlorinated hydrocarbon production zone a gaseous chlorinated hydrocarbon effluent which contains carbon and tars, cooling the effluent to condense a portion of the chlorinated hydrocarbon with the condensed portion containing carbon and tars present in the effluent and introducing at least a portion of the condensed chlorinated hydrocarbon into the chlorinated hydrocarbon production zone to contact the molten salt mixture to oxidize the carbon and tars.
The effluent, containing chlorinated hydrocarbons, carbon and tars, is generally one produced by contacting, in a chlorination (oxychlorination) zone, a hydrocarbon or partially ~, -2a-~07~Z38 chlorinated hydrocarbon with chlorine and/or hydrogen chloride, and a melt containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the multivalent metal. Accordingly, the separated tars and carbon may be conveniently oxidized by introducing the separated tars and carbon into the chlorination ~oxychlorination) reaction zone.
It is to be understood, however, that oxidation of separated tars and carbon by direct contact with the hereinabove described molten salt could be effected in a separate reaction zone designed and operated for the purpose of oxidizing such separated tars or in a reaction zone other than the chlorination reaction zone, in which there is present the hereinabove described molten salt, The hydrocarbon or partially chlorinated hydrocarbon employed as feed to the chlorination reaction zone may be:
an aromatic hydrocarbon, such as benzene; an aliphatic hydro-carbon (gaturated or olefinically unsaturated), preferably a Cl to C4 aliphatic hydrocarbon; or a partially chlorinated derivative of such aromatic and aliphatic hydrocarbons, The most preferred feeds are: ethane, ethylene, methane and the partially chlorinated C2 hydrocarbons.
The process of the present invention is also applicable to the treatment of an effluent containing chlorinated hydrocarbons produced by the dehydrochlorination of a chlorinated hydrocarbon by direct contact with a molten salt mixture, containing the higher and lower valent chlorides of a multivalent metal, which may further include the oxychloride of the multivalent metal.
The chlorides of the multivalent metals used in forming the melt employed in the present invention are generally the chlorides of manganese, iron, copper, cobalt or chromium, preferably copper. The molten mixture generally also includes a metal salt melting point depressant which is non-volatile and resistant to oxygen at the process conditions, such as chloride of a univalent metal; i.e., a metal having only one positive valence state, to provide a salt mixture having a reduced melting point. The univalent metal chlorides are preferably alkali metal chlorides, such as potassium and lithium chloride, 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. A preferred composition is formed from copper chlorides and potassium chloride with the potassium chlorlde comprising from about 20% to about 40%, by weight, of the composition with the remainder being copper chlorides.
In accordance with the present invention, the effluent withdrawn from the melt chlorination zone is at a temperature from about 700 F to about 1200 F, with the specific temperature being dependent upon the feed being chlorinated and the products desired. The chlorination effluent, containing tars and carbon, is then cooled to a temperature at which a portion of the chlorinated hydrocarbon stream, including tars and carbon, i8 condensed. In general, the chlorinated hydrocarbon effluent i8 cooled to a temperature of from about 100 F to about 300F, preferably a temperature of from about 150F to about 280F, and mo9t preferably, a temperature of from about 180F. to ` 1071Z38 about 240F, at which temperature a portion of the chlorinated hydrocarbon stream, including the tars and carbon, is condensed.
In general, such condensation is effected at a pressure from about 0 to about lO0 psig, preferably from about 25 to about 60 psig. The cooling of the effluent to effect such condensation is preferably effected by direct contact quenching with a suit-able quench liquid, such as a chlorinated hydrocarbon (the chlorinated hydrocarbon quench is preferably one or more of the chlorinated hydrocarbons recovered from the effluent).
The chlorinated hydrocarbon effluent condensate, containing tars and carbon, is then oxidized by direct contact with a molten salt mixture, containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the multivalent metal with the oxidation as hereinabove des-cribed, preferably being effected by introducing the condensate into the melt chlorination zone. The oxidation of the separated tars and carbon is effected at a temperature of at least 700F, generally a temperature from 700 F to 1200F, and preferably a temperature from 800 F to 900F. The tars and carbon are combusted to carbon oxide(s) and water, and any chlorinated hydrocarbons present release chloride values as hydrogen chloride and/or chlorine.
In some cases, the condensate separated from the chlorination effluent, containing separated tars and carbon, is introduced into a stripping zone to strip chlorinated hydro-carbon therefrom, and provide a bottom of tar and carbon dis-persed in a sufficient amount of chlorinated hydrocarbon to maintain a flowable stream. In this manner, the total .
- - ~071238 amount of chlorinated hydrocarbon passed to the tar and carbon oxidation steps can be controlled.
The invention will be further described with respect to the accompanying drawing which is a simplified schematic flow diagram of a process for producing vinyl chloride which incorporates the process of the present invention.
Referring now to the drawing, a molten chloride salt, such as a mixture of potassium chloride, cupric and cuprous chloride in line 201 is introduced into the top of an oxidation -vessel 202, maintained at a pressure from about 1 to about 20 atm. and at a temperature of from 600 F to 900 F. A compressed oxygen-containing gas, such as air, introduced through line 203 countercurrently contacts the descending salt to produce copper oxychloride. The feed to reactor 202 may also include chlorine and/or hydrogen chloride (aqueous and/or gaseous) recovered in the process and introduced into reactor 202 to recover chlorine values by generation of cupric chloride.
A gaseous stream is withdrawn, from reactor 202 through line 211 for further processing as required. The molten salt, now containing copper oxychloride, is withdrawn from the bottom of vessel 202 through line 321 and introduced into the top of the reaction vessel 233. The reaction vessel 233 is divided into two reaction sections 233a and 233b, with reaction section 233a functioning as a chlorination Rection and section 233b as a dehydrochlorination section. The molten salt in line 234 is introduced into both sections 233a and 233b.
Fresh feed chlorine and/or hydrogen chloride ls introduced into the bottom of section 233a through line 241, and fre9h feed ethane and/or ethylene, preferably ethane is ' - , 107~238 introduced in line 242 and is combined with a recycle stream comprised of ethyl chloride, ethane and ethylene in line 245 for introduction into the bottom of reaction section 233a.
A liquid chlorinated hydrocarbon stream, containing tars and carbon separated from the chlorination-dehydrochlorination effluent, obtained as hereinafter described, is also introduced into section 233a through line 244.
The reaction section 233a is operated at a temperature of 700 F to 1200F and a pressure of from 1 to 20 atm. to effect chlorination, dehydrogenation and dehydrochlorin-ation of the fresh feed and recycle by direct countercurrent contact of the feed and recycle with the descending molten salt.
Recycle dichloroethane, preferably 1,2-dichloroethane, in line 250 is introduced into reaction section 233b and is countercurrently contacted with the molten salt to effect dehydrochlorination thereof to vinyl chloride.
The effluents from each of the sections 233a and 233b, each containing equilibrium amounts of hydrogen chloride, are combined in the top portion of reactor 233.
An effluent gas, containing vinyl chloride, ethyl chloride, dichloroethane, other chlorinated hydrocarbons (one or more of the following: dichloroethylenes, trichloroethylene, tetrachloroethylene, trichloroethane and tetrachloroethane), ethane, ethylene, water vapor, some hydrogen chloride, (the ma~or portion of the hydrogen chloride produced from dichloro-ethane reacts with the oxychloride of the salt) carbon and tars, rlses into the top of the vessel 233 wherein the effluent 107~Z38 gas is directly contacted with a spray of quench liquid, in particular one or more of the chlorinated hydrocarbons produced in reactor 233, introduced through line 246 to cool the effluent gas and thereby eliminate any vaporized and entrained salts therefrom. The effluent gas is cooled to a temperature at which the salt mixture remains in molten salt form to permit the molten salt to flow back into the reactor 233, The effluent gas, now containing vaporized quench liquid, is withdrawn from vessel 233 through line 247 and intro-duced into a quench vessel 248 wherein the effluent gas iscontacted with chlorinated hydrocarbon quench liquid in line 249 to further cool the gas and thereby separate carbon, tars and any remainin~ entrained salts. The gas is cooled to a temperature at which tars and carbon are separated from the effluent, with essentially no aqueous hydrogen chloride being condensed therefrom. A liquid chlorinated hydrocarbon stream,containing separated tars and carbon is recycled to reactor 233 through line 244, wherein the tars are purged from the system by oxidation. Alternatively, in order to reduce the quantity of chlorinated hydrocarbon returned to reactor 233, all or a portion of the condensate in line 244 is introduced through line 272 into a stripping zone 271 to strip chlorinated hydrocarbons therefrom and provide a flowable bottoms con-taining separated carbon and tar, which is introduced into reactor 233 through line~ 273 and 244. The stripped overhead in line 274 is combined in line 251 with gaseous effluent from quench vessel 248.
Molten salt is withdrawn from the bottom of reactor 233 ~07123~
through line 201 and introduced into vessel 202, for oxidation thereof, as hereinabove described.
The reaction effluent in line 251 is introduced into a separation and recovery zone 261 to separate and recover various components thereof. In particular, hydrogen chloride may be re-covered from the effluent as aqueous hydrogen chloride, and re-cycled to the oxidation reactor 202 to recover the chlorine values.
Heavier chlorinated hydrocarbons are also recovered from the effluent and employed as quench liquid in lines 246 and 249.
Vinyl chloride is recovered as reaction product from separation and recovery section 261. Ethane, ethylene chloride -recovered in separation and recovery section 261 are recycled to reactor 233 through line 245 for ultimate conversion to vinyl chloride. Dichloroethane, prefer-ably only 1,2-dichloroethane, produced in chlorination section 233a is recovered in separation and recovery section 261 and recycled through line 25 to section 233b.
Other chlorinated hydrocarbons comprised of one or more of the following chlorinated hydrocarbons: dichloroethylenes, trichloroethylene, tetrachloroethylene, trichloroethanes and tetra-chloroethanes recovered in separation and recover section 261 can be combusted, with the gaseous chlorine values of the combustion effluent being recovered in oxidation reactor 202.
Although the present invention has been particularly des-cribed with respect to the production of vinyl chloride in asystem employing two reactors, the chlorination and dehydrochlor-ination could be effected in a single zone. Similarly, separate reactors could be used for effecting the dehydrochlorination and ,:
~0~7~Z38 chlorination reactions. Furthermore, the effluents from de-hydrochlorination and chlorination may be separately quenched to separate tars and carbon.
Similarly, the separated tars and carbon could be directly contacted with molten salt in a separate reactor designed and operated for such a purpose.
As a further modification, separated tars and carbon could be combusted in the oxidation vessel.
It is also to be understood that the present invention is also applicable to the chlorination of hydrocarbons other than ethane and/or ethylene. Thus, for example, the hereinabove des-cribed embodiment is also suitable for the chlorination of methane, with reaction 233 being comprised of a single reaction section for chlorination (oxychlorination) of fresh methane feed, recycle methane and chlorinated methane recycle, if any.
-
CHLORINATED HYDROCARBON EFFLUENT
This invention relates to the treatment of an effluent containing chlorinated hydrocarbons, and more particu-larly, to a new and improved process for purging tars and carbon from an effluent containing chlorinated hydrocarbons.
In the chlorination of a hydrocarbon, or partially chlorinated hydrocarbon, the chlorination effluent generally includes tars and carbon which are carried into the separation and recovery system for separating and recovering the various components of the chlorination effluent. In such processes, the tar and carbon materials may cause difficulties in the separation and recovery system. In addition, processing steps must be effected to purge the system of such tars and carbon.
In accordance with the present invention, tars and carbon are separated from an effluent containing chlorinated hydrocarbons, withdrawn from a melt chlorination and/or dehydro-chlorination reaction zone, and the separated tars and carbon are directly contacted with a molten mixture, containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the metal to effect oxidation of the tars and carbon. In this manner, the tars and carbon are effectively purged from the system without being passed through the separa-tion and recovery system for recovering the various chlorinated hydrocarbons.
Thus, in accordance with the present teachings, an improved process is provided for producing a chlorinated hydrocarbon by contacting in a chlorinated hydrocarbon production zone a member selected from the group consisting of a hydrocarbon, chlorinated hydrocarbon and mixtures thereof with a molten salt mixture containing the higher and lower valent chlorides of a multivalent metal selected from the group consisting of copper, ~ -2- ~
~1 , iron, cobalt, chromium and manganese and the oxychloride of the multivalent metals. The process comprises withdrawing from the chlorinated hydrocarbon production zone a gaseous chlorinated hydrocarbon effluent which contains carbon and tars, cooling the effluent to condense a portion of the chlorinated hydrocarbon with the condensed portion containing carbon and tars present in the effluent and introducing at least a portion of the condensed chlorinated hydrocarbon into the chlorinated hydrocarbon production zone to contact the molten salt mixture to oxidize the carbon and tars.
The effluent, containing chlorinated hydrocarbons, carbon and tars, is generally one produced by contacting, in a chlorination (oxychlorination) zone, a hydrocarbon or partially ~, -2a-~07~Z38 chlorinated hydrocarbon with chlorine and/or hydrogen chloride, and a melt containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the multivalent metal. Accordingly, the separated tars and carbon may be conveniently oxidized by introducing the separated tars and carbon into the chlorination ~oxychlorination) reaction zone.
It is to be understood, however, that oxidation of separated tars and carbon by direct contact with the hereinabove described molten salt could be effected in a separate reaction zone designed and operated for the purpose of oxidizing such separated tars or in a reaction zone other than the chlorination reaction zone, in which there is present the hereinabove described molten salt, The hydrocarbon or partially chlorinated hydrocarbon employed as feed to the chlorination reaction zone may be:
an aromatic hydrocarbon, such as benzene; an aliphatic hydro-carbon (gaturated or olefinically unsaturated), preferably a Cl to C4 aliphatic hydrocarbon; or a partially chlorinated derivative of such aromatic and aliphatic hydrocarbons, The most preferred feeds are: ethane, ethylene, methane and the partially chlorinated C2 hydrocarbons.
The process of the present invention is also applicable to the treatment of an effluent containing chlorinated hydrocarbons produced by the dehydrochlorination of a chlorinated hydrocarbon by direct contact with a molten salt mixture, containing the higher and lower valent chlorides of a multivalent metal, which may further include the oxychloride of the multivalent metal.
The chlorides of the multivalent metals used in forming the melt employed in the present invention are generally the chlorides of manganese, iron, copper, cobalt or chromium, preferably copper. The molten mixture generally also includes a metal salt melting point depressant which is non-volatile and resistant to oxygen at the process conditions, such as chloride of a univalent metal; i.e., a metal having only one positive valence state, to provide a salt mixture having a reduced melting point. The univalent metal chlorides are preferably alkali metal chlorides, such as potassium and lithium chloride, 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. A preferred composition is formed from copper chlorides and potassium chloride with the potassium chlorlde comprising from about 20% to about 40%, by weight, of the composition with the remainder being copper chlorides.
In accordance with the present invention, the effluent withdrawn from the melt chlorination zone is at a temperature from about 700 F to about 1200 F, with the specific temperature being dependent upon the feed being chlorinated and the products desired. The chlorination effluent, containing tars and carbon, is then cooled to a temperature at which a portion of the chlorinated hydrocarbon stream, including tars and carbon, i8 condensed. In general, the chlorinated hydrocarbon effluent i8 cooled to a temperature of from about 100 F to about 300F, preferably a temperature of from about 150F to about 280F, and mo9t preferably, a temperature of from about 180F. to ` 1071Z38 about 240F, at which temperature a portion of the chlorinated hydrocarbon stream, including the tars and carbon, is condensed.
In general, such condensation is effected at a pressure from about 0 to about lO0 psig, preferably from about 25 to about 60 psig. The cooling of the effluent to effect such condensation is preferably effected by direct contact quenching with a suit-able quench liquid, such as a chlorinated hydrocarbon (the chlorinated hydrocarbon quench is preferably one or more of the chlorinated hydrocarbons recovered from the effluent).
The chlorinated hydrocarbon effluent condensate, containing tars and carbon, is then oxidized by direct contact with a molten salt mixture, containing the higher and lower valent chlorides of a multivalent metal and the oxychloride of the multivalent metal with the oxidation as hereinabove des-cribed, preferably being effected by introducing the condensate into the melt chlorination zone. The oxidation of the separated tars and carbon is effected at a temperature of at least 700F, generally a temperature from 700 F to 1200F, and preferably a temperature from 800 F to 900F. The tars and carbon are combusted to carbon oxide(s) and water, and any chlorinated hydrocarbons present release chloride values as hydrogen chloride and/or chlorine.
In some cases, the condensate separated from the chlorination effluent, containing separated tars and carbon, is introduced into a stripping zone to strip chlorinated hydro-carbon therefrom, and provide a bottom of tar and carbon dis-persed in a sufficient amount of chlorinated hydrocarbon to maintain a flowable stream. In this manner, the total .
- - ~071238 amount of chlorinated hydrocarbon passed to the tar and carbon oxidation steps can be controlled.
The invention will be further described with respect to the accompanying drawing which is a simplified schematic flow diagram of a process for producing vinyl chloride which incorporates the process of the present invention.
Referring now to the drawing, a molten chloride salt, such as a mixture of potassium chloride, cupric and cuprous chloride in line 201 is introduced into the top of an oxidation -vessel 202, maintained at a pressure from about 1 to about 20 atm. and at a temperature of from 600 F to 900 F. A compressed oxygen-containing gas, such as air, introduced through line 203 countercurrently contacts the descending salt to produce copper oxychloride. The feed to reactor 202 may also include chlorine and/or hydrogen chloride (aqueous and/or gaseous) recovered in the process and introduced into reactor 202 to recover chlorine values by generation of cupric chloride.
A gaseous stream is withdrawn, from reactor 202 through line 211 for further processing as required. The molten salt, now containing copper oxychloride, is withdrawn from the bottom of vessel 202 through line 321 and introduced into the top of the reaction vessel 233. The reaction vessel 233 is divided into two reaction sections 233a and 233b, with reaction section 233a functioning as a chlorination Rection and section 233b as a dehydrochlorination section. The molten salt in line 234 is introduced into both sections 233a and 233b.
Fresh feed chlorine and/or hydrogen chloride ls introduced into the bottom of section 233a through line 241, and fre9h feed ethane and/or ethylene, preferably ethane is ' - , 107~238 introduced in line 242 and is combined with a recycle stream comprised of ethyl chloride, ethane and ethylene in line 245 for introduction into the bottom of reaction section 233a.
A liquid chlorinated hydrocarbon stream, containing tars and carbon separated from the chlorination-dehydrochlorination effluent, obtained as hereinafter described, is also introduced into section 233a through line 244.
The reaction section 233a is operated at a temperature of 700 F to 1200F and a pressure of from 1 to 20 atm. to effect chlorination, dehydrogenation and dehydrochlorin-ation of the fresh feed and recycle by direct countercurrent contact of the feed and recycle with the descending molten salt.
Recycle dichloroethane, preferably 1,2-dichloroethane, in line 250 is introduced into reaction section 233b and is countercurrently contacted with the molten salt to effect dehydrochlorination thereof to vinyl chloride.
The effluents from each of the sections 233a and 233b, each containing equilibrium amounts of hydrogen chloride, are combined in the top portion of reactor 233.
An effluent gas, containing vinyl chloride, ethyl chloride, dichloroethane, other chlorinated hydrocarbons (one or more of the following: dichloroethylenes, trichloroethylene, tetrachloroethylene, trichloroethane and tetrachloroethane), ethane, ethylene, water vapor, some hydrogen chloride, (the ma~or portion of the hydrogen chloride produced from dichloro-ethane reacts with the oxychloride of the salt) carbon and tars, rlses into the top of the vessel 233 wherein the effluent 107~Z38 gas is directly contacted with a spray of quench liquid, in particular one or more of the chlorinated hydrocarbons produced in reactor 233, introduced through line 246 to cool the effluent gas and thereby eliminate any vaporized and entrained salts therefrom. The effluent gas is cooled to a temperature at which the salt mixture remains in molten salt form to permit the molten salt to flow back into the reactor 233, The effluent gas, now containing vaporized quench liquid, is withdrawn from vessel 233 through line 247 and intro-duced into a quench vessel 248 wherein the effluent gas iscontacted with chlorinated hydrocarbon quench liquid in line 249 to further cool the gas and thereby separate carbon, tars and any remainin~ entrained salts. The gas is cooled to a temperature at which tars and carbon are separated from the effluent, with essentially no aqueous hydrogen chloride being condensed therefrom. A liquid chlorinated hydrocarbon stream,containing separated tars and carbon is recycled to reactor 233 through line 244, wherein the tars are purged from the system by oxidation. Alternatively, in order to reduce the quantity of chlorinated hydrocarbon returned to reactor 233, all or a portion of the condensate in line 244 is introduced through line 272 into a stripping zone 271 to strip chlorinated hydrocarbons therefrom and provide a flowable bottoms con-taining separated carbon and tar, which is introduced into reactor 233 through line~ 273 and 244. The stripped overhead in line 274 is combined in line 251 with gaseous effluent from quench vessel 248.
Molten salt is withdrawn from the bottom of reactor 233 ~07123~
through line 201 and introduced into vessel 202, for oxidation thereof, as hereinabove described.
The reaction effluent in line 251 is introduced into a separation and recovery zone 261 to separate and recover various components thereof. In particular, hydrogen chloride may be re-covered from the effluent as aqueous hydrogen chloride, and re-cycled to the oxidation reactor 202 to recover the chlorine values.
Heavier chlorinated hydrocarbons are also recovered from the effluent and employed as quench liquid in lines 246 and 249.
Vinyl chloride is recovered as reaction product from separation and recovery section 261. Ethane, ethylene chloride -recovered in separation and recovery section 261 are recycled to reactor 233 through line 245 for ultimate conversion to vinyl chloride. Dichloroethane, prefer-ably only 1,2-dichloroethane, produced in chlorination section 233a is recovered in separation and recovery section 261 and recycled through line 25 to section 233b.
Other chlorinated hydrocarbons comprised of one or more of the following chlorinated hydrocarbons: dichloroethylenes, trichloroethylene, tetrachloroethylene, trichloroethanes and tetra-chloroethanes recovered in separation and recover section 261 can be combusted, with the gaseous chlorine values of the combustion effluent being recovered in oxidation reactor 202.
Although the present invention has been particularly des-cribed with respect to the production of vinyl chloride in asystem employing two reactors, the chlorination and dehydrochlor-ination could be effected in a single zone. Similarly, separate reactors could be used for effecting the dehydrochlorination and ,:
~0~7~Z38 chlorination reactions. Furthermore, the effluents from de-hydrochlorination and chlorination may be separately quenched to separate tars and carbon.
Similarly, the separated tars and carbon could be directly contacted with molten salt in a separate reactor designed and operated for such a purpose.
As a further modification, separated tars and carbon could be combusted in the oxidation vessel.
It is also to be understood that the present invention is also applicable to the chlorination of hydrocarbons other than ethane and/or ethylene. Thus, for example, the hereinabove des-cribed embodiment is also suitable for the chlorination of methane, with reaction 233 being comprised of a single reaction section for chlorination (oxychlorination) of fresh methane feed, recycle methane and chlorinated methane recycle, if any.
-
Claims (5)
1. An improved process for producing a chlorinated hydrocarbon by contacting in a chlorinated hydrocarbon production zone a member selected from the group consisting of a hydrocarbon chlorinated hydrocarbon and mixtures thereof with a molten salt mixture containing the higher and lower valent chlorides of a multivalent metal selected from the group consisting of copper,iron, cobalt chromium and manganese and the oxychloride of said multivalent metal,which comprises:
withdrawing from the chlorinated hydrocarbon production zone a gaseous chlorinated hydrocarbon effluent, containing carbon and tars;
cooling said effluent to condense a portion of the chlorinated hydrocarbons, said condensed portion containing carbon and tars present in the effluent; and introducing at least a portion of the condensed chlorinated hydrocarbon into the chlorinated hydrocarbon production zone to contact said molten salt mixture to oxidize the tars and carbon.
withdrawing from the chlorinated hydrocarbon production zone a gaseous chlorinated hydrocarbon effluent, containing carbon and tars;
cooling said effluent to condense a portion of the chlorinated hydrocarbons, said condensed portion containing carbon and tars present in the effluent; and introducing at least a portion of the condensed chlorinated hydrocarbon into the chlorinated hydrocarbon production zone to contact said molten salt mixture to oxidize the tars and carbon.
2. A process according to claim 1 wherein the molten salt mixture contains cuprous chloride, cupric chloride and copper oxychloride.
3. A process according to claim 2 wherein the condensed chlorinated hydrocarbon portion containing the carbon and tars is stripped of a portion of the chlorinated hydrocarbon prior to introducing thereof into the chlorinated hydrocarbon production zone.
4. A process according to any one of claims 1, 2 or 3 wherein the chlorinated hydrocarbon is produced from a C1-C4 aliphatic hydrocarbon.
5. A process according to any one of claims 1, 2 or 3 wherein said cooling to condense a portion of the chlorinated hydrocarbon is effected by direct contact quenching to effect cooling to a temperature of from 100°F to 300°F at a pressure of from 0 to 100 psig.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/488,459 US3992460A (en) | 1972-03-27 | 1974-07-15 | Purging of tars and carbon from chlorinated hydrocarbon effluent |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071238A true CA1071238A (en) | 1980-02-05 |
Family
ID=23939761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA231,406A Expired CA1071238A (en) | 1974-07-15 | 1975-07-14 | Purging tars and carbon from chlorinated hydrocarbon effluent |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS5134105A (en) |
| AR (1) | AR219272A1 (en) |
| BE (1) | BE831342A (en) |
| BR (1) | BR7504457A (en) |
| CA (1) | CA1071238A (en) |
| DE (1) | DE2530517A1 (en) |
| ES (1) | ES439368A1 (en) |
| FR (1) | FR2278664A1 (en) |
| GB (1) | GB1476043A (en) |
| IT (1) | IT1039796B (en) |
| NL (1) | NL7508427A (en) |
| SE (1) | SE7508033L (en) |
| TR (1) | TR18732A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU633465A3 (en) * | 1975-09-10 | 1978-11-15 | Хемише Верке Хюльс Аг, (Фирма) | Method of reprocessing chlorohydrocarbon waste |
| JPS57116535A (en) * | 1981-01-13 | 1982-07-20 | Tokyo Shibaura Electric Co | Digital channel selection repeating device |
| JP4450401B2 (en) | 2000-12-15 | 2010-04-14 | 本田技研工業株式会社 | Snowblower scraper |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3548016A (en) * | 1967-04-11 | 1970-12-15 | Lummus Co | Chlorine values recovery and use |
| DE2261795C3 (en) * | 1972-12-16 | 1975-05-28 | Basf Ag, 6700 Ludwigshafen | Process for the production of hydrogen chloride by thermal cleavage of organic substances containing chlorine |
-
1975
- 1975-07-09 DE DE19752530517 patent/DE2530517A1/en not_active Withdrawn
- 1975-07-11 AR AR25954275A patent/AR219272A1/en active
- 1975-07-14 IT IT2540175A patent/IT1039796B/en active
- 1975-07-14 BE BE158277A patent/BE831342A/en unknown
- 1975-07-14 BR BR7504457A patent/BR7504457A/en unknown
- 1975-07-14 ES ES439368A patent/ES439368A1/en not_active Expired
- 1975-07-14 SE SE7508033A patent/SE7508033L/en not_active Application Discontinuation
- 1975-07-14 CA CA231,406A patent/CA1071238A/en not_active Expired
- 1975-07-14 GB GB2940575A patent/GB1476043A/en not_active Expired
- 1975-07-15 FR FR7522105A patent/FR2278664A1/en active Granted
- 1975-07-15 TR TR1873275A patent/TR18732A/en unknown
- 1975-07-15 JP JP8659075A patent/JPS5134105A/en active Pending
- 1975-07-15 NL NL7508427A patent/NL7508427A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| BE831342A (en) | 1975-11-03 |
| FR2278664A1 (en) | 1976-02-13 |
| DE2530517A1 (en) | 1976-01-29 |
| SE7508033L (en) | 1976-01-16 |
| NL7508427A (en) | 1976-01-19 |
| ES439368A1 (en) | 1977-02-16 |
| AR219272A1 (en) | 1980-08-15 |
| AU8302475A (en) | 1977-01-20 |
| GB1476043A (en) | 1977-06-10 |
| JPS5134105A (en) | 1976-03-23 |
| FR2278664B1 (en) | 1980-05-30 |
| TR18732A (en) | 1977-07-27 |
| IT1039796B (en) | 1979-12-10 |
| BR7504457A (en) | 1976-07-06 |
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