IL33146A - Perchlorination process - Google Patents

Description

π * X > » n i ^ a 1 » > τ ♦ n n Perchlorination process 33146/2 The present invention relates to the thermal perchlorination of hydrocarbons and partially chlorinated hydrocarbons under elevated pressures.

Carbon tetrachloride and perchloroethylene are produced commercially by the thermal chlorination of lower aliphatic hydrocarbons as well as their partially chlorinated derivatives at elevated temperatures in excess of about 400°C. These compounds can be produced by direct thermal chlorination of methane, ethane, propane, ethylene, propylene or - la - their partially chlorinated derivatives . Hydrocarbons having 4 or more carbon atoms in the molecule can also be used, although less desirably, due to the formation. of a greater amount of hexachlorobutadiene , hexachlorocyelopen-tadiene, and hexachlorobenzene as by-products. Practically speaking, hydrocarbons or partially chlorinated hydrocarbons having from 1 to 3 carbon atoms are to be preferred for the purpose. Chemical reactions which occur are set out in some detail in U.S. Patent 2,442,324. It is known from the prior art, including U.S. Patent 2,857,438, that the optimum reaction temperature for the production of carbon tetrachloride and perchloroethylene under substantially atmospheric conditions is between 50° C. to 800° C. A particularly, desirable reactor for carrying out the perchlorinatlon reaction is described in U.S. Patent 2,806,768.

The effluent withdrawn from a perchlorinatlon the: react'§r" described, in reaction zone of/u.S. Patent 2,806,768 contains hydrogen chloride and unreacted chlorine as well, as chlorinated hydrocarbon products, including perchloroethylene and carbon tetrachloride. Some hexachlorobenzene is usually produced under perchlorinatlon conditions and is withdrawn from the effluent before it reaches the recovery zone. Chlorinated hydrocarbons (which are also referred to as "RCl" herein) are recovered from the by-product hydrogen chloride and excess chlorine, and thereafter chlorine and hydrogen chloride are separated to the desired degree. In conventional anhydrous systems for the separation of RCl from hydrogen chloride and chlorine, costly refrigeration is required in order to achieve the desired degree of separation of RCl. Also, in conventional processes where it is desirable to effect separation stripping system to make the desired separation between hydrogen chloride and chlorine. Unfortunately, the cost of installation, operation and maintenance of the prior and conventional wet hydrogen chloride absorption-stripping and drying systems employed In perchlorinatlon processes has a substantial adverse effect on the economics of such process It is, therefore, the principal object of the present invention to overcome and eliminate inheren disadvantages and to provide an economically attractive and efficient perchlorinatlon process; and to provide a combination of various simple and economical processing steps which renders the by-product hydrogen chloride gas with or without chlorine present, economically useful to subsequent known commercial processes, for production of chlorinated hydrocarbons..

Another objec of the present invention is to provide a vapor' phase thermal perchlorinatlon process which can utilize as hydrocarbon feed saturated aliphatic hydrocarbons containing from one to about three carbon atoms and chlorinated derivatives thereof, ethylenically unsaturated aliphatic hydrocarbons and chlorinated derivatives thereof containing from one to about three carbon atoms and as a portion of the hydrocarbon feed saturated aliphatic hydrocarbons and chlorinated derivatives thereof,, and ethylenically unsaturated aliphatic hydrocarbons and chlorinated derivatives thereof containing four carbon atoms .

Another object of the present invention Is to provide a perchlorinatlon reaction product containing only minor amounts of partially chlorinated compounds such as chloroform and trichloroethylene . or a major portion of perchloroe.thylene .

Another object of the present invention Is to provide an economical and efficient method for recovering relatively pure, anhydrous hydrogen chloride from the effluent of a perchlorinatlon reaction zone under an elevated pressure .

Another .object of the present invention is to provide a high pressure perchlorinatlon process which is more economical to install than prior processes of this type .

.Another object of the present invention is to provide an efficient method of separating RCl from hydrogen chloride and chlorine which does not require refrigeration to effect the desired degree of separation.

Other objects and advantages vlll become apparent to those skilled In the art from the following description and disclosure.

Summary of the Invention These and other objects are generally accomplished in accordance with the process of the present invention by carrying out the perchlorinatlon of saturated or unsaturated aliphatic hydrocarbons as well as the partially chlorinated derivatives thereof to produce carbon tetrachloride and perchloroethylene under elevated pressures and temperatures . Preferred feed materials include Cx to C3 hydrocarbons or their partially chlorinated derivatives; however, a portion of the carbon feed can be obtained from the Inclusion of C4 aliphatic hydrocarbons and chlorinated derivatives thereof in the feed to the reactor. When the vapor phase thermal perchlorinatlon process of the present invention is carried out at pressures between about 60 and about 200 psig., and Into engineering design of a perchlorination plan are achieved. The temperatures known in the prior art, and particularly between about 475° C. and about 700° C. are suitable for the elevated pressure reaction of the present Invention. A mos preferred temperature range is between about 550 ° C. and about 6500 C.

The effluent from the perchlorination reaction is quenched and passed to a suitable partial condensation zone to condense chlorinated hydrocarbon material therefrom. The remaining gaseous material containing hydrogen chloride and chlorine can be withdrawn and used at high pressure .

Detailed Description of the Invention The process of the present invention can utilize reactors which require feed preheat to. sustain the perchlorination reaction such as taught in U.S. Patent 2, 829 , 589 , or which require external hot gas recirculation to sustain the reaction as taught in U.S. Patent 2,441, 528 , or which require a bed of fluidized material to sustain the reaction; but a reactor such as described in U.S. Patent 2 , 806 , 768 has been found suitable for the process of the present invention.

Aliphatic hydrocarbons containing up to about four carbon atoms and their chlorinated derivatives can generally be utilized to make carbon tetrachloride and perchloroethylene in the process of the present invention. It is, however, preferred to use materials containing less than four carbon atoms as reactants In the process of the present invention. The use of materials having four carbon atoms as reactants generally produces a reaction mixture which contains a larger proportion of compounds containing more than two carbon atoms than is produced when compounds having less than four carbon atoms are used as reactants .

Among the aliphatic hydrocarbons and their chlorinated ethylene dichloride, . methyl chloroform, acetylene tetrachloride, hexachloroethane , ethylene, vinyl chloride, vlnylidene chloride, trlchloroethylene, propane, propylene, n-propyl chloride, is.o ro yl chloride, dichloropropanes , dlchloropropenes , trichloropropanes , trichloropropenes , tetrachloropropanes , tetrachloropenes , and the like.

Butane, butene, chlorobutanes such as dlchloro-butanes, trichlorobutanes , tetrachlorobutanes and chloro-butenes such as dichlorobutenes, trichlorobutenes , and tetrachlorobutenes , and the like can be reacted in the process of the present invention to form carbon tetrachloride and perchloroethylene . Their use however, produces a reaction product containing a higher percentage of hexa-chlorobutadlene and hexachlorobenzene impurities, than reaction products of compounds containing less than four carbon atoms. It has been found that the partially chlorinated aliphatic C4 compounds can generally constitute a considerable portion of the hydrocarbon feed without adversely affecting the perchlorination reaction.

It must also be realized however, that highly chlorinated compounds in the hydrocarbon feed may not contribute to the heat .of reaction or may have an endothermic heat of reaction in the perchlorination process of the present Invention. It is therefore, preferred in the practice of the present invention to utilize a hydrocarbon feed mixture which has an exothermic net heat of reaction sufficient to sustain the reaction in view of the heat losses in a commercial reactor.

It has been noted that the perchlorination reaction reaches substantial completion in less than one second in the concentration of partially chlorinated compounds such as chloroform and trichloroethylene in the reaction product can each reach a concentration above 50- 100 parts per million. To avoid concentration of partially chlorinated compounds above about 100 parts per million it is preferred to allow the reaction to proceed for more than one second and preferably from about 3 to about 40 seconds and most preferably 4 to 12 seconda Longer reaction times are generally not deleterious to the reaction but merely add to the size and cost of the reactor.

The temperature of the reaction is generally controlled in the desired range by the addition of chlorinated reaction products and excess chlorine, as diluents for the reaction. The composition of the reaction product can be Influenced by the composition of the materials used as the diluent. The use of a mixture rich in carbon tetrachloride as a diluent will favo the production of perchloroethylene while the use of a mixture rich in perchloroethylene as a diluent will favor the production of carbon tetrachloride . The range of products obtainable by the utilization of diluent compositions can be seen from Table A to range from a 100 percent carbon tetrachloride product to a substantially 100 percent perchloroethylene product.

Table A shows the liquid reaction product mixtures produced by the practice of the process of the present invention. The reaction: as conducted in a substantially empty reactor of the form described in U.S. Patent 2 , 806 , 768 . The conditions were varied to show the effect of reactants, diluents, residence times and temperatures on the typical liquid reaction product mixtures of the present invention.

The liquid reaction product mixtures were obtained by totally condensing a portion of the reactor outlet stream in a 5 percent reagent grade sodium hydroxide solution.

When samples containin more than about 0.50 percent C6Clfi were collected, methylene chloride was added to the sodium hydroxide solution to prevent the C6C16 from crystallizing out of the reaction product mixture. The reaction product-mixture was separated from the sodium hydroxide solution, dried and analyzed by gas chromatography. The samples were R) analyzed on a Hewlett-Packard Model 810 using a l inch by 15 foot column packed with 20 percent Silicone SE-30 H) on Chromosorb P . A 5 micro-liter sample was used. The results tabulated in Table I show the composition of the reaction product mixture after the removal of the chlorine and hydrogen chloride .

The vapor phase thermal perchlorination reaction produces an effluent containing carbon tetrachloride, perchloro-ethylene, hydrogen chloride, unreacted chlorine, and small amounts of the by-products hexachloroethane, hexachlorobutadiene and hexachlorobenzene . This effluent is withdrawn' rom the per- ' chlorination reaction zone under an elevated pressure and passed first to a quenching zone to reduce the temperature; of the reactor effluent, at elevated pressure. Quenching is achieved, for example, by contacting the hot gaseous reaction effluent with subsequently recovered RC1. Conditions in the quench zone can be maintained such that hexachloroethane, hexachlorobenzene and hexachlorobutadiene are completely condensed together with most of the perchloroethylene, which is an excellent solvent therefor. It is important to remove hexachlorobenzene prior to introduction of the reaction effluent to the condensation zone . It is also important to remove Run 1 2 3 .4 . 5 6 Pressure 125 125. 125 125 125 125 (Pounds per square inch gauge) Temperature (Degree C) ■640 ■ 565 590 ■ 5°^ 622 Residence Time (Seconds) 8.4 " . 7.6 6.2 5.1 12.6 " 11.2 .6 (Pound mole per hour, Liquid) Liquid Reaction Products (Weight Percent) ecu 97.8 82.8 84 78 .1 82.2 63.55 73 C2 C14 1.6 I5.7 . 13.6 19 .2 I5.O 29.26 22 C2Clg 0.37 1.23 I.5 1 .72 2.5I 5.24 3 c4ci6 0.02 0.01 0.12 0 .17 O.I5 Ο.26 0 CgClg 0.19 Ο.25 0.11 0 .23 0.19 1.69 0 CHCI3 (Parts per million) 22 45 44 60 C HCI3 (Parts per million) 0 0 0 0 Weight Product Ratio CCL 51 5.27 1.5 358 Ο * (Miscellaneous Mixture) 1,1,2 -Trichloroethane by .7 1, 1, 1,2-Tetrachlor Mole Percent 1.2-Dichlorobutane .98 1 , 1 ,2 ,2-Tetrachlor 1 ,2-Dichloroethane 0.92 1.3-Dichlorobutane 1.49 1.3-chloro-2-buten Trichloroethylene O.I5 1.4 -dichlorobutene they can be returned to the reaction zone for ultimate reformation to carbon tetrachloride and perchloro-ethylene . The conditions in the quench zone can also be controlled to effect the desired degree of separation of carbon tetrachloride, which is removed In the overhead material, from perchloroethylene which can be concentrated in the bottom of the quench zone, if quench zone fractionation is employed.

The overhead gaseous material withdrawn from the · quench zone retains substantially . all of the hydrogen chloride and excess chlorine- admixed with remaining RCl which includes carbon tetrachloride and residual perchloroethylene . This gaseous material is passed to a partial condensation zone, preferably comprising several partial condensers in series, in which RCl is largely condensed and separated from the remaining gaseous material comprising hydrogen chloride and chlorine. In the process of this invention the partial condensation zone is maintained under an elevated pressure which is preferably between about 6o and about 200 psig. and most preferably between about 95 and about 1 5 psig.

The terminal temperature of the partial condensation zone can be as high as from about 35° C. to about 55° C. depending on the operating pressure. These conditions permit the use of cooling water as the coolant at: the terminal region of the partial condensation zone while still achieving the degree of separation of RCl and HC1-C12 mixtures achieved in prior processes through the use of refrigeration.. Conse-quentiy, one highly advantageous feature of the present invention is the. elimination of this costly refrigeration load .

The gaseous material containing hydrogen chloride and chlorine which is withdrawn from the partial condensation zone under an elevated pressure is suitable for introduction to a wide variety of hydrogen chloride consuming reaction zones either directly or with further purification as is hereinafter exemplified. Additionally, the gaseous material containing hydrogen chloride under, an elevated pressure can be introduced to most hydrogen chloride consuming reaction zones without further compression thereof. One substantial drawback of prior attempts to utilize the hydrogen chloride off gases from prior perchlorination processes in hydrogen chloride consuming processes operated at elevated pressures, e.g., methane oxychlorinatlon, was that it required substantial compression of the hydrogen chloride or the hydrogen chloride and chlorine feed stream.

Certain hydrogen chloride consuming reaction zones e.g., methane and ethylene dichlorlde oxychlorinatlon zones, are tolerant of the presence of chlorine in the hydrogen chloride. Other hydrogen chloride consuming reaction zones such as, e.g., ethylene and benzene oxychlorinations , and methanol hydrochlorination, are not tolerant of chlorine admixed with the hydrogen chloride. Therefore, as is more fully hereinafter exemplified, the. gaseous material con- . talning hydrogen chloride and chlorine obtained from the partial condensation zone is, firstly, passed to a chlorine consuming reaction zone prior to its introduction to certain hydrogen chloride consuming reaction zones which are not tolerant of chlorine.

Numerous preferred and alternative embodiments of the present invention will become apparent from the Figure 1 of the drawings illustrates diagram-matically, in elevation, one preferred embodiment of the present invention, wherein the elevated pressure perchlor-inatlon reaction of the present invention is combined with a Ci partial chlorinatlon plant followed by a methanol hydrochlorination process or, alternatively, an ethylene oxychlorination process.

Figure 2 of the drawings shows an elevated pressure perchlorlnatlon process combined with a process for the oxychlorination of ethylene.

Figure 3 of the drawings shows the combination of an elevated pressure perchlorlnatlon process with a methane oxychlorination process.

Figure 4 of the drawings shows an elevated pressure perchlorination process combined with an ethane oxychlorination process, or, alternatively, an ethylene dichloride oxychlorination process .

Reference is now made to specific examples of operation and to. various embodiments of the process of the present invention, which are described with reference to detailed description of the several figures of the drawings.

EXAMPLE I .

Referring to Figure 1, l4.;5 lb. moles/hr . propylene vapor in line 10, 103-9 lb. moles hr. chlorine vapor in line 12 and 102.1 lb,.moles of a vapor in line 14 comprising 86 carbon tetrachloride, 5.5$. chlorine and 8. $ HC1 are admixed and injected into thermal, perchlorination reactor . A vapor stream comprising 3.9 lb. moles hr . perchloro-ethylene, 2.1 lb. moles hexachloroethane and 1.4 lb. moles hexachlorobutadiene from a hexachlorobenzene removal system described hereinafter (not shown in the drawing) is also admixed with the foregoing feed stream to the reactor. Λ suitable reactor is described' in U.S. Patent 2>8o6,768.

The maximum reactor temperature is 590° C. and retention time in the reactor is 16 seconds . Reactor operating pressure is 125 psig.

The hot reactor exit gases in line l6 are cooled by contact in quench zone l8 with recycle liquid from line 22 thereby condensing hexachloroethane, hexachlorobutadiene, hexa-. chlorobenzene and perchloroethylene which is removed in line 17. Stream 17 is withdrawn at a rate to avoid dissolution of hexachlorobenzene in the base of 18 and is sent to a vaporizer system (not shown) in which perchloroethylene is largely returned to the bottom of the quench column while a small amount of perchloroethylene vapor containing nearly all the hexachlorobutadiene and hexachloroethane is returned to the reactor inlet. This procedure leaves an accumulating amount of hexachlorobenzene behind, as a liquid, which is then removed from the vaporizer.

A crude RC1 stream 23, comprising the net production and containing by-product hexachloroethane formed in the quench zone and recovery zone is sent to a fractional distillation purification system (not shown) for recovery, subsequent neutralization and drying of .7 lb. molesAir. technical carbon tetrachloride and .17.5 lb. moles hr. perchloroethylene product. About 0.5 l . moles hr. by-product hexachloroethane along with 2.7 lb. moles hr. perchloroethylene recycle from the distillation system is returned to the perchlorination reaction zone 15 either as a liquid or as a vapor .

The remaining gases are passed in line 19 to partial condensation zone 20, which is maintained at a terminal temperature of about 40° C. Chlorinated hydrocarbons are condensed and recycled in line 22 to provide reflux in zone l8. The composition of reflux stream 22 is 86^ CC14, 5.5% Cl2 and 8.5 HC1. The remaining gas in line 24 which leaves partial condensation zone 20 contains 12.5 lb. moles/hr. Cl2, 87 'lb. moles/hr. HC1, and 2.4 Lb. moles hr. CC14. The pressure in zone 20 is maintained about 115—120 psig.

The foregoing non-condensable gas stream is then admixed with chlorine from line 27 Introduced into an operating methyl chloride partial chlorlnation zone 25· A suitable methyl chloride partial chlorlnation zone is described in U .S . Patent 3,126,419. The methyl chloride reactor operated with the following feed prior to introduction of the perchlorlnation effluent.

TABLE I Fresh CH3CI i 64.0 lb; moles/hr.

Recycle CH3CI 90.5 lb. moles/hr.

Cl2 -87.I lb. moles/hr.

CH2CI2 28.3 lb. moles/hr.

HC1 42.7 lb. moles hr.

Maximum temperature in zone 25 is 450° C, while producing a reactor effluent consisting of: TABLE II HC1 128.2 lb. moles/hr.

CI2 ' Trace CH3CI 18 .9 lb. moles/hr. > When the perchlorinatlon zone effluent In line 2 Is introduced in the methyl chloride partial chlorinatlon zone 25, the feed to the methyl chloride partial chlorinatlon reactor becomes the following: TABLE III .215.8 lb. moles/hr 87.I lb. moles /hr 123.2 lb. moles /'hr 2.4 lb. moles/ hr 24.0 lb. moles/hr 452.5 lb. moles/hr.

The exit gas leaving the reactor after stabilizing to the foregoing Table III feed condition is as follows: TABLE IV HC1 210.3 lb. moles/hr.

Cl2 Trace CH3CI 151.8 lb. moles/hr.

CH2C12 68.8 lb. moles hr.

CHCI3 15. lb. moles, hr.

CCI4 6.2 lb. moles/hr. 452.5 lb. moles, hr.

The partial chlorinatlon effluent in line 26 is quenched in zone 28 and passed in line 29 to partial condensation zone 30, where it is cooled stepwise (cooling water condenser followed in series by a refrigerated condenser) to a temperature of about -5° C . at 100 psig. to the quench zone 28; and the net chlorinated hydrocarbon crude product is withdrawn in line 32. This material is sent to a conventional product distillation system, and neutralizing and drying system for recovery of technical, chlorinated hydrocarbon products .

Non-condensable gas leaving the recovery system in line .34 analyzes as follows: ■ ' TABLE V Cl 174.1 lb. moles/hr.

CI g Trace CH3C1 23.7 lb. moles/hr.

Part of the non-condensable gas in line 3.4 is then Introduced to a conventional methanol hydrochlorinatlon zone 38 for production of 64.0 lb. moles/hr. methyl chloride.

Methanol hydrochlorination is well known for example, see U.S. Patent No. 1,834, 089 or French Patent No. 1,471, 895 . The methyl chloride product is usually obtained as a dry vapor from the methanol hydrochlorination recovery system which is then compressed to about 125 psig. and returned in line 37 to the partial chlorlnation zone 25 as a vapor.

Alternately, the methyl chloride product can be obtained as a liquid and be fed by centrifugal pump to the partial chlorlnation zone as a. highly atomized feed as in U.S. Patent No. 3 , 126 , 419 , or it may be vaporized ahead of the partial chlorlnation zone and added s a vapor as per U.S. Paten 3 , 126 , 419. This material is the methyl chloride feed described in Table I.

The remaining non-condensable gas in line 34 includes 102.4 lb. moles hr. HC1, 13 ·9 lb', moles/hr .. CH3CI , Into the bottom of an adlabatlc, Irrigated sieve plate scrubbing column 40 which is fed at the top with C2C14 at a temperature of -20° C. as absorbent feed. The previously chilled perchLoroethylene leaving the bottom of scrubbing column 40 in line 41 and containing 13-9 lb. moles/hr. CH3C1 can be returned to quench zone 28 allowing recovery of the methyl chloride and perchloroethylene . Alternately, a stripping column (not shown) can be installed for the purpose of stripping the 13.9 lb- moles/hr. CH3CI from the perchloroethylene. The CH3CI is returned to line 32. The perchloro-" ethylene, is cooled and chilled for closed circuit recycle back to scrubbing column 40.. The scrubbed gas leaving the top of column 40 in line 42 has the following composition at' 100 psig.

■ ■ TABLE VI HC1 102.4 lb. moles/hr.

C2C14 .04 lb. moles/hr'.

The material in line 42 is introduced together with ethylene in line 43 and air (or other Suitable source of oxygen) in line 44 to an ethylene oxychlorination zone 5 in which essentially all of the HC1 is converted principally to ethylene dichloride. A suitable ethylene oxychlorination process is described, for example, in British Patent No. 1,104,666.

EXAMPLE II The thermal perchlorination feeds and effluent are the same as in Example I. Referring to Figure 2, the. non-condensable gas exiting condensation zone 20 in line 24 contains 12.5 lb. moles/hr.. Cl2, 87 lb . moles Αιτ·. HC1 and bottom of an Irrigated sieve plate scrubbing column 5C which is fed at the top with an absorbent comprising C2C14 at ° C. Stream 51 containing 2 A lb. moles, hr . CC14 and. a small amount of chlorine and hydrogen chloride can be returned to the quench zone l8.. The gas leaving the to ' of this adiabatic scrubbing column in line 52 consists of the following: .

TABLE VII HC1 87 lb. moles/hr .

.Cl2 12. lb. moles hr.

C2C1 OA lb. moles,hr .

The gas in line 2 is mixed with 59-0 -lb. moles/hr. ethylene introduced from line ^ a d introduced to a catalytic addition chlorination reactor 55· Reactor contains suitable means for catalyzing the addition chlorination of ethylene along with suitable means for removing the exothermic reaction heat. The indirect cooling system provided for the reaction zone is such that the maximum temperature reached is between 100° C. and 200° C. for a vapor phase reaction or 0° to 6o° C. for liquid phase reaction.

Essentially, complete reaction of CI2 with excess ethylene takes place, and the effluent of zone 55 is passed in line 58 to ethylene oxychlorlnation zone 45 where air is added and reaction takes place in conventional ethylene, oxychlorlnation equipment as described in Example I.

EXAMPLE III The thermal perchlorlnation feeds and effluen are the. same as in Example I. Referring to Figure j5, the non-condensable gas exiting condensation zone 20 in line 2 consists, of 12.5 lb. moles/hr. Cl2, 87 "lb. moles, hr. HC1 and 2.4 lb. moles/hr. CC14. This material is admixed with methane and air or oxygen. This combined vapor is then fed' to methane oxychlorination reaction zone 60 such as, e.g., described in British patent No. 587,969, to produce methyl chloride, methylene chloride, chloroform, carbon tetrachloride, and a small amount of perchloroethylene (denoted as RC1 in Figure 3).

EXAMPLE IV The thermal perchlorination feeds and effluent are the same as in Example I. Referring to Figure 4, the non-condensable gas exiting the condensation zone 20 in line 24 is fed to a fractionation column 65. Preferably, the contents of line 24 are dried, e.g.,- to a water content less than about -20 ppm in an irrigated concentrated sulfuric acid drying column prior to introduction to Column 65. This preferable treatment minimizes the . formation of hydrates of HC1 and Cl2 and thereby improves and extends the operation of Column 65. Refrigerated reflux condenser 68 returns liquid HC1 reflux in line 70 to the top of Column 65. The bottom product consisting primarily of Cl2 is recycled to the thermal perchlorination reactor in line 67. The overhead product consisting of substantially anhydrous, purified HC1 is passed in line 72 to an ethane oxychlorination zone 74 where it is admixed with ethane and air or oxygen. Zone 74 produces principally ethyl chloride and dlchloroethanes . . An example of an ethane oxychlorination zone is described in British Patent No. 938,096.

EXAMPLE V Referring again bo Figure 4 , this example is conducted the same as Example IV except that the HCl In line 72 is passed through valve 75 in line 77 Into an ethylene dichloride oxychlorination zone 78 where it is admixed with . ethylene dichloride and air or oxygen. This process produces trichloroethylene and perchloroethylene as described, for example, as a second stage reaction In British Patent 90^ , 0 .

EXAMPLE VI This example is conducted the same as Example IV except that the HCl in line 72 is admixed with benzene and air or oxygen. This mixture is fed to a benzene oxychlorination reaction system, for example, either according to the Raschig (Prahl) process described in British Patent ."562 , 817 or as described in Chem. and Met. Engr . 47 , No. 11 , Pages 770 — 775 , ( 1940 ) . Chiefly, monochlorobenzene is formed with good hydrogen chloride utilization and with only minor amounts of polychlorinated benzene by-products being formed .

EXAMPLE VII- This example is conducted the same as Example IV except that the HCl in line 72 is admixed with acetylene and air or oxygen. This mixture is fed to an acetylene oxychlorination reaction system, e.g., as described in British Patent 1 , 090 , 783 . . Products of the reaction include dichloroethylene , trichloroethylene arid some more highly chlorinated ethylenes or ethanes . Steam and inert gases may also be Introduced with the feed raw materials in such an acetylene Dechlorination process to improve yields by EXAMPLE νΐΐΐ This example la conducted the same as Example IV except that HC1 In line 72 Is admixed with . ethylene . This mixture is fed to a liquid or vapor phase hydrochlorinatlon reactor containing an active catalyst for production of ethyl chloride. A suitable liquid phase ethyl chloride process is described, e.g., In Canadian Patent 448,020.

EXAMPLE IX This example Is conducted the same as Example IV except that HCl in line 72 is admixed with, toluene. This mixture is. fed to a toluene chloromethylation process containing toluene and paraformaldehyde In the presence of zinc chloride, e.g.., as described in. Blane , Bull . Soc . Ohim . ,. 1923, 313. In this reaction, the chloromethyl group is introduced to the toluene ring in high yield and the reaction is carried out either in a batch or continuous manner .

Having thus described the invention with reference to numerous examples of operation thereof, many modification and alterations will become apparent to those skilled in the art without departing from the spirit and scope thereof.

Claims (14)

1. What is claimed is:

   1 . A process which comprises carrying out the vapor phase thermal perchlorlna ion of suitable hydrocarbon and partially chlorinated hydrocarbon feed materials under an elevated temperature and a pressure which is above about βθ psig. to produce a vaporous effluent comprising chlorinated hydrocarbons, hydrogen chloride and unreacted chlorine, quenching said effluent, passing the cooled gaseous material to a partial condensation zone maintained under an elevated pressure between about 6o psig. and about 200 psig. and a terminal temperature up to about 55 ° C. to condense chlorinated hydrocarbon material therefrom, and withdrawing gaseous material containing hydrogen chloride and chlorine from said partial condensation zone.
2. 2 . The process of Claim 1 in which said thermal perchlorlnation reaction is carried out under an elevated pressure between about oO and about 200 psig.
3. 5 - The process of piaim 1 in which said thermal perchlorlnation reaction is carried out under an elevated pressure between about 100 and about 150 psig.
4. 4 . The process of Claim 1 in which said partial condensation zone is maintained at a pressure between about 95 and 1^5 psig. and a terminal temperature between about 35 ° C. and abou 55° C .
5. 5 . The process of Claim 1 in which said gaseous material containing hydrogen chloride and chlorine withdrawn from said partial condensation zone is passed as feed material to a hydrogen chloride consuming reaction
6. 6. The process. of Claim 1 in which said gaseous material containing hydrogen chloride and chlorine withdrawn from said partial condensation zone is passed as feed material to a chlorine consuming reaction zone and then to a hydrogen chloride consuming reaction zone .
7. 7· The process of Claim 5 in which chlorine is removed from said gaseous material prior to its- introduc- ■ tion to a hydrogen chloride consuming reaction zone. .
8. 8. The process of laim i in which said gaseous material comprising hydrogen chloride and chlorine withdrawn from said partial condensation zone is passed as feed material to a partial chlorlnatlon zone.
9. 9- The process of Claim 1 in which said gaseous material comprising hydrogen chloride and chlorine withdrawn from said partial condensation zone is admixed with-ethylene and subjected to addition chlorlnatlon conditions to convert the chlorine content thereof to ethylene dlchlorlde and passing the resulting material to an ethylene' o.xychlorlnatlon reaction zone . .
10. 10. The process of Claim 1 in which said gaseous material comprising hydrogen chloride and chlorine withdrawn from said partial condensation zone is admixed with ethylene and subjected to addition chlorlnatlon conditions -to convert the chlorine content thereof to ethylene di-chloride removing a portion of the ethylene dlchlorlde thus formed, and passing the resulting material to an ethylene oxychlorination reaction zone.
11. 11. The process of Claim 1 in which said gaseous material containing hydrogen chloride and chlorine withdrawn from said partial condensation zone is passed as feed material to a methane oxychlorinatlon reaction zone operated at an elevated pressure below the operating pressure, of said partial condensation zone.
12. 12. The process of Claim 1 in which said gaseous material containing hydrogen chloride and chlorine withdrawn from said partial condensation zone is passed to a purification zone wherein chlorine Is separated from the resulting substantially anhydrous, purified hydrogen chloride, and passing such hydrogen chloride as feed material to a hydrogen chloride consuming reaction zone.
13. 15-. The process of Claim 12 in which a portion of said purified hydrogen chloride is withdrawn as a product.
14. 14. The process of Claim 12 in which said

    hydrogen chloride consuming reaction zone is selected from the group consisting of an ethylene oxychlorinatlon reaction zone, an ethane oxychlorinatlon reaction zone, an ethylene diehloride oxychlorinatlon reaction zone, a benzene oxychlorinatlon reaction zone, an acetylene oxychlorinatlon reaction zone, an ethylene hydrochlorlnation reaction zone, a toluene chloromethylation reaction zone, and a

    methanol hydrochlorlnation reaction zone.

    of Claim 7

    15· The process /which comprises carrying out a

    •of the feed material vapor phase thermal perchlorination reaction under an elevated temperature at an elevated pressure above about 6o psig. to produce a vaporous effluent comprising hydrogen chloride, chlorinated hydrocarbon material including carbon tetrachloride, perchloroethylene, hexachloroethane, hexa-chlorobutadiene, hexachlorobenzene, and unreacted chlorine, withdrawing said effluent and passing same to. a quenching zone maintained under conditions to condense hexachloro-. · ethane, hexachlorobutadlene, hexachlorobenzene and perchloroethylene therefrom, passing the remaining gaseous material to a partial condensation zone maintained under a pressure between about 6o and4 about 200 psig. at a terminal temperature up to about 55° C. to condense

    chlorinated hydrocarbon material from a remaining gaseous material comprising hydrogen chloride and chlorine, and passing at least a portion of said remaining gaseous material as feed material to a suitable hydrogen chloride consuming reaction zone.

    l6. The process of Claim 15 in which a portion of said remaining gaseous material is passed as feed material to a chlorine consuming reaction zone and then to a hydrogen chloride consuming reaction zone .