IL32663A - Process for methane oxychlorination - Google Patents

Description

B-Pocesa for fiet!mr-e 9a¾re¾loriEStion ST SKS CSXgSXCAJi- ΟΟ ΡΑΒΪ C: 30973 -The pifceenL appllcaLluti Is a uuiiLlimaLluil-ll.-p^—Of" ■Au&usL 2 , 1968. " The present invention relates to a process for the chlorination of hydrocarbons and, in particular, to an integrate process for the oxychlorination of methane.

The patent literature on the subject of chlorination of hydrocarbons is most extensive. Much has been said on the subject of processes for the oxychlorination of methane but, to date, there is not an existing, functioning, economical process in the field.

The term "oxychlorination" utilized herein in the specification and claims refers to metal halide catalyzed processes in which gaseous hydrogen chloride, chlorine, or a mixtur of hydrogen chloride and chlorine is used as a chlorinating i agent. These processes involve chlorination of hydrocarbons or chlorohydrocarbons with hydrogen chloride and an oxygen-containi gas such as air or elemental oxygen. The process takes place co veniently in the presence of a metal halide catalyst such as cupric chloride impregnated on a suitable carrier. It has been postulated that in these oxychlorination reactions, the hydrogen chloride is oxidized to chlorine and water and the chlorine reac with the organic material present in the feed gas.

An object of the present invention is to provide an economical process for the chlorination of hydrocarbons.

A second object of this invention is to provide an . integrated economical process for the oxychlorination pf methane Another object of this invention is to reduce the oxidation of methane and the explosion hazards associated with the use of pure oxygen as a feed gas to a methane oxychlorina-tion reaction zone.

Another object of this invention is to prevent the corrosive contact effect of the fluidized catalyst bed upon the reactant feed gas distribution means.

Yet another object of the present invention is to provide a method of pre-condensation zone desuperheating of the gaseous effluent leaving the reaction zone and removal of material entrained in the gaseous effluent.

A further object of the present invention is to provide a method of preventing freezing of condensate from occurring in the low temperature condensation zone.

Yet still another object of this invention is to provide a method of recovering and recycling low-boiling chlorinated methanes employing suitable reactant feed material.

Further objects and advantages of the present invention will become apparent to those skilled in the art from the following description and disclosure.

The objects of the present invention are accomplished in the following manner.

In the methane oxychlorination process of this invention, a reactant feed mixture containing methane, a source of oxygen such as air or oxygen and a chlorinating agent selected from the group consisting of hydrogen chloride, chlorine and mixtures of hydrogen chloride and chlorine is fed into a reactio zone. These reactant materials are preferably introduced into the reaction zone through a suitable gas distribution means. In a preferred embodiment a stationary bed of non-reactive, particu late material is maintained in the bottom portion of the reactio zone enveloping the gas distribution in order to prevent the corrosion of the gas distribution means. Any suitable material, e.g., quartz or other grog material, capable of withstanding reaction zone conditions may be employed. The bed of particulat material surrounding the gas distribution means prevents the fluidized catalyst bed from coming into direct contact with the gas distribution means. The reaction zone contains a suitable methane oxychlorination catalyst which is maintained as a den6e fluidized bed of catalyst particles.

Preferably, a suitable heat extraction means is maintained within the confines of the fluidized bed of catalyst.

The catalyst bed is kept in a fluidized state by the upward flow of the reaction gases. The gaseous effluent withdrawn from the reaction zone contains chlorinated methanes, hydrogen chloride, chlorine, unreacted methane, non-condensable gaseous material and entrained solid material , e.g. , catalyst fines and tars.

In passing the gaseous effluent from the reaction zone to the quench zone, the gaseous effluent passes from a conduit a a high temperature to the quench zone of much lower temperature. At the transition from hot conduit to cold quench zone, the line used to carry to gases is subject to rapid corrosion by the cooled gaseous effluent. It has been discovered that the ^sert of a short spool or collar of material which is corrosion resistant in the gaseous effluent line or pipe from the reaction zone prevents this transition zone corrosion. The term "transition zone" as employed herein refers to the point at which the temperature of the conduit connecting the oxychlorination reactor and the quench zone is at the dew point of the gaseous reaction effluent flowing through the conduit. The use of a corrosion resistant collar eliminates the need to have all the piping from the reaction zone made completely of corrosion resistant material which is generally more expensive. The collar or spool can be made of tantalum, brick-lined steel, carbon-lined steel or other corrosion resistant materials.

The gaseous effluent of the reaction zone is passed into a quench zone where it is desuperheated. The quenching reduces the temperature of the gaseous effluent to the proximity of its dew point. The term "proximity of its dew point" includes temperatures up to about 20°C. above the actual dew point of the gaseous reactor effluent. Tars and entrained catalytic fines are removed from the gaseous effluent in the quench zone.

The desuperheated gaseous effluent is passed from the quench zone to a first condensation zone which is maintained under conditions to condense chlorinated methanes and hydrochloric acid from the gaseous effluent. The condensate is passed to a suitable product recovery zone. The remaining gases are passed into a second condensation zone maintained at a lower temperature than the first zone. As a method of preventing freezing of condensate in the lower temperature condensation zone, the ratio of hydroge chloride to water in the gaseous materials is adjusted to a suitable level as described later herein. The chlorinated methanes and hydrochloric acid which condense in the second condensation zone are also passed to the product recovery zone.

A small percentage of relatively low boiling chlorinated methanes remain in the gaseous material leaving the second condensation zone. These gases are fed to an absorption zone wherein a suitable solvent absorbs chlorinated methanes from the gaseous material. The absorption zone can be operated at a high pressure than the rest of the system if desired. Solvent enriched with chlorinated methanes is fed to a stripping zone. Preferably, at least a portion of one or more of the gaseous reactants employed as feed to the reaction zone is used to strip chlorinated methanes from the solvent. The gaseous stream containing chlorinated methanes is then passed to the reaction zone The foregoing and other aspects of the invention will become more apparent from a consideration of the following illustrative description and the accompanying drawings.

Figure 1 illustrates diagrammatically, in elevation, one embodiment of the process of the present invention.

Figure 2 shows diagrammatically, in elevation, an alternative embodiment of the operation of the reaction zone illustrated in Figure 1.

Figure 3 shows diagrammatically, in elevation, modific tions suitable for the quench zone illustrated in Figure 1.

Having described the process of the present invA.ition ί in general terms , reference is now made to Figure 1.

Methane, which may be obtained from crude or refined natural gas, is introduced in line 10. The material in line 10 is passed through heater 7 into a stripping column 74 to remove low-boiling chlorinated hydrocarbons for recycle as will be discussed in more detail later. Stream 10 is pressurized in compressor 80 and fed together with recycle material to reaction zone 25 in line 12. Air is fed to reaction zone 25 in line 16. Other oxygen-containing gases or oxygen alone, which have been compressed and purified to the extent necessary to protect the catalyst in the reaction zone 25 can be employed as feed in line 16. Hydrogen chloride is fed to reaction zone 25 in line 18, which may also contain substantial amounts of chlorine and minor amounts of harmless impurities such as O2, CO2 and chlorinated hydrocarbons. Alternatively, line 18 can represent a byproduct stream from another process, such as, e.g., the per-chlorination of propylene or propylene dichloride, or from the cracking of ethylene dichloride to vinyl chloride monomer. Compression of stream 18 may be necessary depending on its source. One of the important economic considerations in this process is that impure, by-product hydrogen chloride, which is usually difficult to dispose of, can be used profitably. Additional chlorine is fed to reaction zone 25 in line 14 as needed to achieve the desired production of chlorinated methanes. Additional recycle, e.g., chlorinated methanes, is fed to the reaction zone in line 34 to achieve the desired product distribution. The addition of this material can also be used to help cool reaction zone 25 or to reduce hazards of fire and explosion during the reaction.

Reaction zone 25 can be about 15 ft. in diameterrand about 20 to about 30 ft. in height, and can be constructed of or clad with Inconel or nickel or can be lined with brick or gunite in order to withstand the corrosive effects of the catalyst at elevated temperatures of the oxychlorination reaction. It is to be understood that any suitable dimensions and materials of construction can be employed. Reaction zone 25 contains a fluid bed 29 of suitable methane oxychlorination catalyst, e.g., about 5 to about 20 feet in depth. Suitable heat extraction means are preferably contained within the confines of the fluid bed to maintain the desired temperature for the methane oxychlorination.

Preferably, such heat exchange means comprises a plurality of interconnected tubes 27 through which is passed a suitable heat transfer fluid, e.g., Dowtherm A. In order to reduce corrosion of the heat exchange surfaces maintained in contact with the fluidized catalyst the temperature of the heat transfer fluid passed through the heat exchanger is maintained at a temperature between about 230°C. and about 325°C. Maintaining the temperature in this range results in an unexpectedly large reduction in corrosion as compared with teachings of the prior art. The heat transfer tubes 27 within the reactor may be constructed of Inconel, nickel or other suitable corrosion resistant materials.

The reaction feed and recycle streams are introduced into the bottom of reaction zone 25 through suitable gas distribution means 15 and 9, respectively. A stationary bed of crushed quartz (particle size between about 1/4" and about 2") is disposed in the bottom of the reaction zone to a depth which is sufficient to envelope the gas distribution means. The reaction gases pass upwardly through the catalyst at a superficial velocity which is preferably maintained between about 0.1 feet/sec and about 2 feet/sec. at reaction conditions. The temperature of the fluid bed within reaction zone 25 is preferably maintained between about 350eC. and about 600°C, although a temperature between about 370°C. and about 450eC. is most preferred. The pressure within the reactor is preferably maintained between about zero psig. and about 200 psig., although the range of from about 5 psig. to about 100 psig. is more preferred. Under these conditions the feed gases react to produce chlorinated methanes. One notable feature of the methane oxychlorina ion reaction is that only small quantities of hydrogen chloride leave the reactor, unlike the chlorination of methane in which there is formed one mole of hydrogen chloride for each mole of chlorine reacted to chlorinated methane. This is an important economic consideration, since problems of marketing, recycling or disposing of large quantities of hydrogen chloride or hydrochloric acid are minimized.

A gaseous reaction effluent is withdrawn from reactor 25 in conduit 20 at about reaction temperature. These gases are passed through a cyclone separator to remove a portion of catalyst fines from the gases. Th«i gases are then fed to a desuperheating, or quench zone 31.

The gases can be passed through a collar 28 of corrosion resistant material such as tantalum, brick-lined steel or the like, where conduit 20 enters the relatively cold quench zone 31. This is the so-called transition zone in which corrosion of line would otherwise occur due to the cooling of conduit 20 which causes condensation of acidic material at the point where line 20 is connected to quench zone 31. Insertion of collar 28 eliminates such corrosion.

In quench zone 31, the reaction gases are preferably contacted with a suitable liquid to desuperheat and remove solid material from the gaseous material. Suitable liquids include crude or partially refined chlorinated methanes introduced in line 24 as well as hydrochloric acid solution. The liquid is fed at a rate such that it is partially vaporized by the hot reaction gases, thusly achieving a temperature of the resulting gaseous mixture which is in the proximity of its dew point. The temperature of the gaseous material in line 22 also depends on the pressure and the composition of the liquid and gaseous streams entering quench zone 31. A preferable temperature range for material in line 22 is between about 60°C. and 150eC. This de-superheating of the reaction gases is advantageous in that less heat exchange area is needed to condense the product gases. The addition of crude chlorinated methanes in line 24 makes it possible to condense the chlorinated methanes products at a highe temperature and thus the condensation is more economical. The condensation temperature can be further increased by introducing partially refined carbon tetrachloride in line 24. This factor is particularly important at lower pressures, e.g., about zero to about 60 psig. Another advantage inherent in the use of quench zone 31 is that tars and catalyst fines, which are carried out of the reactor, are collected and drawn off in line 33. Quench zone 31 can, be made of brick-lined, acid proof construction or of any other suitable material. An aid to gas-liquid contacting can be employed within the quench zone, e.g., any corrosion resistant packing or tray can be used. Condensed liquid is withdrawn in line 33.

Desuperheated reaction gases leave quench zone 31 in line 22 and are conducted to condensation zone 35. The piping through which stream 22 passes must be constructed of carbon or brick-lined steel, tantalum or other suitable corrosion resistant material. Zone 35 is a water cooled condensation zone wherein both hydrochloric acid and chlorinated methanes are condensed. Condensation zone 35 is constructed of corrosion resistant material such as impervious graphite, tantalum or other resistant materials. The condensing gases arc. preferably passed through the tube side of the heat exchangers in order to conserve on corrosion resistant materials of construction. The remaining gaseous material and condensate in line 38 enter a gas-liquid separation zone 39 and condensate is separated in line 42. Line 42 contains hydrochloric acid and chlorinated methanes. Gaseous material in line 40 is conducted to refrigerated condensation zone 43, which is maintained preferably at a terminal temperature between about 10°C. and about -50°C. Prior to introduction of gaseous material into condensation zone 43, it is usually necessary to make adjustments in its composition in order to prevent freezing of the condensate formed in condensation zone 43. Two situations can occur which lead to freezing of condensate in condensation zone 43. The first case is where the gaseous material in line 40 contains a high proportion of water relative to the hydrogen chloride contained therein, i.e., less than about 12 weight percent hydrogen chloride in the hydrochloric acid condensed, such that ice will form before the terminal temperature in condensation zone 43 is reached. The second case is where th gaseous material in line 40 contains a high proportion of hydrog chloride relative to the water contained therein, i.e. , above about 50 weight percent hydrogen chloride in the hydrochloric acid condensed such that a solid hydrate of hydrogen chloride will form before the terminal temperature is reached. In either of these cases, it is possible to avoid freezing of the condensa and pluggage of the condenser by adjusting the ratio of hydrogen chloride and water in line 40 so that the aqueous liquid condensed therefrom will not freeze even at the lowest temperatures in the condensation zone 43. This adjustment is accomplished by adding an amount of hydrogen chloride or water, whichever is required, through line 36 to line 40 in order to adjust the proportion of hydrogen chloride in line 40 to between about 12 weig percent and about 50 weight percent hydrogen chloride in the hydrogen chloride-water condensate and preferably to between about 17 and about 45 weight percent hydrogen chloride.

Hydrochloric acid and chlorinated methanes are condensed in zone 43. The condensation zone 43 may be constructed of corrosion resistant materials, such as impervious graphite, tantalum, or other resistant materials. The condensed liquid an remaining gaseous material is passed in line 44 to gas-liquid separation zone 45. Any mist or fog remaining in the gas is removed in separator 51. Any moisture remaining in the stream in line 30 is removed in dryer 65, thus reducing corrosion problems The resulting gaseous stream 66 is at a temperature between abou and about -50eC. and contains, in addition to non-condensable gases, which include 02, CH^, C02, considerable quantities of methyl chloride and some methylene chloride. These light chlorinated methanes are recovered for recycle to the reaction zone 25 by absorbing them in a solvent, such as perchloroethyle carbon tetrachloride, 1,3-hexachlorobutadiene or other suitable solvent. If desired, the pressure of this stream can be raised prior to absorption to increase the absorption efficiency. The absorption is preferably carried out by counter-currently contacting the rich gaseous stream 66 with cold lean liquid solven in absorption zone 68 which may contain packing or trays to fur ther improve the contacting efficiency. The rich solvent leave the bottom of 68 and is stripped at low pressure, about zero to about 60 psig. in stripping zone 74 with ,the methane feed strea 10, or with another suitable gaseous feed stream. The methane feed or other suitable gaseous feed stream in 10 is preferably heated in 7 to supply the heat of vaporization to the chlorinat methanes. Hydrogen chloride can be introduced in line 10 inste of methane.

Stripping zone 74 contains suitable packing or trays 75. The lean solvent leaving 74 in line 77 is cooled to a temperature of between about 10°C. and about -50°C. in 79 and then returned to the absorption zone 68. Lean gas in line 32 from 68 is passed through heater 70. The lean gas is then eith vented or fed to a furnace or heater where the methane remainin therein may be beneficially burned for its heating value.

Condensed liquid derived from the condensation zones in lines 42 and 46 is combined and passed to tank 47 in line 26. The liquid is allowed to settle in tank 47 to separate an aqueou hydrochloric acid phase from a chlorinated methanes phase.

The condensed hydrochloric acid may be sold as aqueous acid, or a portion of it can be recirculated to the quench zone 31. Alternatively, such acid can be dehydrated by distillation in the presence of strong calcium chloride solution, and the resulting dry hydrogen chloride then either recycled as part of stream 18 or sold as a product as of the process.

A stream of crude chlorinated methanes is withdrawn from tank 47 in line 24 and passed to the quench zone 31 previously described. Alternatively, the crude chlorinated methanes can be separated into a light fraction and a heavy fraction containing carbon tetrachloride which is recirculated to zone 31. The remaining condensed chlorinated methanes are drawn off in line 53 and sent to a suitable product recovery zone. In one embodiment of the product recovery zone, stream 53 is fed to one or more distillation columns. As much methyl chlor ide as is needed as an isolated product is separated as is desired. The remaining methyl chloride is recycled, e.g., in stream 34 to be further chlorinated. If no net methyl chloride production is desired, no methyl chloride distillation column is required. In this case, the methyl chloride can be removed entirely from the product stream in a methylene chloride distillation column wherein product methylene chloride is separated as desired, the remaining undistilled product stream being recycled, e.g., in stream 34. The product stream or streams contain the desired marketable amounts of methyl chloride, methylene chloride, chloroform and carbon tetrachloride.

Reference is now made to Figure 2, which illustrates an embodiment of the invention in which essentially pure oxygen as distinguished from air is fed to the methane oxychlorination reactor 25. In this embodiment, vent gases in line 32 are admixed with a gaseous material comprising oxygen in line 16 and such mixture is conducted into reactor 25. This dilution of the pure (>2 feed is advantageous in that it reduces the amount of methane which is oxidized and at the same time reduces the explosive hazards associated with the feed to a methane oxychlorination reaction zone using pure as part of the feed. The vent gases in line 32 are a mixture containing CO, CO2» CH^, and (^, as well as a small percentage of ^ and CH3CI. The composition of vent gases varies depending upon the operation of the recovery system and the ratio of vent gas recycle to oxygen feed. Use of vent gas as diluent permits unexpectedly greater utilization of CH^, CH^Cl and O2 which might otherwise be lost to the atmosphere or be employed as low cost fuel. Moreover, this method of diluting O2 feed as compared with using enriched air reduces the 2 concentration in the system, thereby reducing the extent of gas purging which is required. The reactor effluent is withdrawn through cyclone separator 129 and passed in line 20 for processing as described with reference to Fig. 1 or Fig. 3.

Reference is now made to Figure 3 which illustrates a preferred method of desuperheating the gaseous reactor effluent in line 20. The gaseous effluent in line 20 is at about the temperature of reaction in 25. Since line 20 is a conduit of small cross sectional area compared to reactor 25, the velocity of aseous material in 20 is hi h relative to the velocit in reactor A. or in quench zone 31. Quench liquid, which is preferably liquid chlorinated methanes, hydrochloric acid or mixtures thereof, is sprayed into line 20 by means of line 21, thereby deeuper-heating the gaseous effluent to a temperature in the proximity of its dew point, e.g., 100°C. to about 150°C. Excellent contact is obtained between the hot reactor gases in line 20 and the quench liquid in line 21 by reason of the high velocity in line 20.

Preferably, the liquid chlorinated methanes, hydrochloric acid or mixtures thereof in line 21 are obtained from the oxychlorination process, e.g., from tank 47. Desuperheated material is contacted with additional cool liquid from line 56 in quench zone 31.

Liquid is withdrawn in line 33 and recycled, at least in part via line 50 pump 52 and line 54 to water cooled heat exchanger 55.

The liquid is preferably cooled to between about 30 and about 120°C. and most preferably between 40 and 80°C. This additional cooling in 55 results in improved heat transfer characteristics in the system.

Example 1 As a specific example of the operation of the oxychlorination process represented in Figure 1, reference is made to Tables I and II.

TABLE I PROCESS OPERATING CONDITIONS Temperature °C. Pressure PSIG Unit Number (Fig. 1) To£ Bottom Inlet Outlet (Reactor) 440 440 95 90 (Heat exchange tubes) 260 250 30 20 (Quench zone) 130 300-400 90 89 (First condenser) 130 45 89 85 (Second condenser) 45 -25 85 83 (Crude product tank) 25 25 -(Absorption zone) -20 4 83 82 (Stripping column) 10 10 2 1 i TABLE II PROCESS FEED RATES ALL FLOWS ARE IN POUND MOLE Chemical Unit Numbers in Figure Formula 10 12 14 16 18 20 CH4 . 420 420 168 - CH3C1 110 140 CH2C12 8.6 224.9 CHC13 91.7 cci4 12.4 HC1 321.6 52.8 H20 507.5 N2 1350 1350 1 359.1 47.7 °2 CO 10.5 co2 52.5 ci2 80.1 33.7 1.1.

PHASE V V V V V V Vapor Liquid TABLE II (Continue PROCESS FEED RATES ALL FLOWS ARE IN POUND MOLES/H Chemical Unit Numbers in Figure 1 Formula 30 32 34 36 38 40 CH 168 168 168 , CH3C1 110 30 218.7 190 CH2C12 8.6 792.1 259 CHC13 332.2 47.5 cci4 44.8 3.2 »-» HC1 3.0 52.8 0.7 H20 507.3 30 w2 47.7 47.7 47.7 47.7 CO 10.5 10.5 10.5 10.5 co2 52.5 52.5 52.5 52.5 ci2 PHASE V β Vapor L = Liquid Example 2 This example illustrates the embodiment described with reference to Figure 2. This example is carried out essentially as specified in Example 1 except that about two-thirds of the vent gas in line 32 is recycled and admixed with substantially pure (>2 in line 16 for introduction to reaction 25. A numerical example is presented in Table III.

TABLE III ALL FLOW RATES ARE LB. MOLES/HOUR Unit Numbers in Figure 2 Chemical 32 32 16 10 Formula Vent Recycle O Feed CH+ Feed CH4 56.0 112.0 308.0 °2 15.9 31.8 327.3 CO 10.5 21.0 co2 52.5 105.0 Example 3 This example Illustrates the embodiment described with reference to Figure 3. A numerical example is presented in Table IV.

TABLE IV ALL FLOW RATES ARE LB. MOLES/HOUR HC1 Unit Numbers in Figure 3 Take¬ Chemical off Formula 20 21 31 50 56 22 28 (33) CH, 168 168 CHoCl 140 140 CH2C12 224.9 224.9 CHClo 91.7 91.7 CC1; 12.4 12.4 HC1 52.8 243 1870 1870 38.5 14.3 H20 507.5 1853 14240 14240 406.0 101.5 N, 1350 1350 47.7 47.7 CO 10.5 10.5 CO, 52.5 52.5 CI, 1.1 Temp. eC. 440 45 110 100 45 77.5 110 100

Claims (13)

WHAT IS CLAIMED IS:

1. A methane oxychlorination process which comprises: (a) reacting a gaseous material comprising methane, an oxygen-containing gas and a chlorinating agent selected from the group consisting of hydrogen chloride, chlorine and a mixture of hydrogen chloride and chlorine in a reaction zone in the presence of a suitable fluidized oxychlorination catalyst to produce a gaseous effluent containing chlorinated methanes, unreacted chlorinating agent, non-condensable gaseous material including methane, and entrained solid material; (b) desuperheating said effluent and separating entrained solid material therefrom; (c) passing the desuperheated effluent to a condensation zone maintained under conditions to condense chlorinated methanes and hydrochloric acid from a remaining gaseous material containing non-condensable material including methane, and relatively low-boiling chlorinated methanes and separating condensate from the remaining non-condensable gaseous material (d) separating a stream comprising relatively low-boiling chlorinated methanes from said remaining non-condensable gaseous material including methane, and passing at least a portion of said chlorinated methanes to step (a) .

2. The method of Claim 1 in which said reacting is carried out at a temperature maintained between about 350eC. and about 600°C.

3. The method of Claim 1 in which said reacting is carried out at a temperature between about 370°C. and about 450 °C.

4. The method of Claim 1 in which said reacting is carried out at a pressure between about zero psig. and about 200 psig.

5. The method of Claim 1 in which said reacting is carried out at a pressure between about 5 psig. and about 100 psig.

6. The method of Claim 1 in which said effluent from step (a) is desuperheated to a temperature between about 60 and about 150 °C.

7. The method of Claim 1 in which said condensation zone of step (c) is maintained at a terminal temperature between about 10 °C. and about -50 °C.

8. The method of Claim 1 in which solid pluggage is avoided in the condensation zone of step (c) by addition of hydrogen chloride or water, whichever is required, to material flowing through the condensation zone such that the resulting condensate contains between about 12 and about 50 weight percent hydrogen chloride.

9. The method of Claim 1 in which solid pluggage is avoided in the condensation zone of step (c) by addition of hydrogen chloride or water, whichever is required, to material flowing through the condensation zone such that the resulting condensate contains between about 17 and about 45 weight percent hydrogen chloride.

10. The method of Claim 1 in which said oxygen-containing gas comprises oxygen; and admixing at least a portion of said remaining non-condensable gaseous material including methane of step (d) with said oxygen prior to its introduction to said reaction zone of step (a). 52663/2 - 24 -

11. h@ method of Claim 1 in which methane is ro g into contact with said β tream comprising relatively low-boiling chlorinated methanes i a stripping zone to produce a giseous mixture comprising methane and lou-boiling chlorinated methanes tihich is passed to said abaction sone of step (a),

12. The method of Claim 8 wherein the aslatively low-boiling chlorinated methanes are separated from the remaining non-condensable gaseous material including methane with a suitable solvent under absorption conditions, a solvent stream containing th© relatively low-boiling chlorinated methanes is sepa; ted, the oolvont stream is contacted with a methane or hydrogen chloride containing gaseous feed Stream under conditions to strip low-boiling diorinated methanes from the solvent stream, and the gaseous feed stream containing the low-boiling chlorinated raethanes is mssed to the reaction zone.'

13. 2 method of Claim 12 in which the solvent is selected from the group consisting of perehloroethylene, carbon tetrachloride, and 1,3-hexachlorobutadiene· For the Applicants i E