Aug. 17, 1948. C. M. FONTANA 2,447,323 ABSORBENT MEDA

IWWEWTOR

4770'RAVEY

Aug. 17, 1948. C. M. FONANA 2,447,323 OXGEN ABSORBENT MEDIA Filed Aug. 7, 1944 3. Sheets-Sheet 3 ???

3. ?

20

20 % of CoAA2 SAZT 4.S. CUPRIC CALOALDE A /ELT 77Z/ 32 MOZ. 272 ACZ AF TVG. 3 Celeste 4. Föntaga AY ???ht??????????? 47 ????????? Patented Aug. 17, 1948 2,447,323 UNITED STATES PATENT OFFICE ?2.44?.32? OxG3NASSORSENT SEA Celeste ME, Fontging, Dallas, Tex, assignor, by mesme assignments, to socony-Vacuum 0i: Company, incorporated, New York, N.YY., a cor poration of New York Appleation August 8, 1944, Seria No. 543,349 Claim. (C. 2 This invention relates to a method of extract The most widely used method for producing ing oxygen from the air by the use of molten is the electrolytic method. Other methr comprising the of in admixture ods involve.the recovery of chlorine from hydro . . with metal , especially gen . The prior art &mployed in general, chlorides such as postassium chloride. More par two methods for converting chloride ticularly the invention is concerned with the preparation of melt mixtures of copper chlorides catalyticto chlorine. oxidation The offirst hydrogen method chloride involves to directchlo and chloride in concentrations so ad rine. Common among the catalysts employed justed that the melting points of such mixtures have been copper halides supported on porous are sufficiently low that oxygen may be absorbed 10 materials such as pumice. Promoted copper Catar from the air by the liquid melts as hereinafter lysts having some other substance added to in described and as described in greater detail in prove their catalytic activity have also been pro U. S. Patent 2,418,402. The invention is also con posed. Addition agents suggested as effective are cerned with the preparation of such melts for oxygen compounds of , beryllium, mag utilization in the process of making chlorine and 15 nesium, bismuth, antimony, uraniuxin and rare chlorinated hydrocarbons as described and earth metal compounds. These catalytic proc claimed in U. S. Patents 2,407,828, 2,418,930 and esses all suffer from the same disadvantage, viz., 2,418,93. the products from the catalytic converters re The present invention concerns the optimum quire difficult and expensive treatment in order concentrations of the chlorides of copper and of 20 that quantitative yields of pure chlorine be ob potassium chloride in said melts to obtain high, tained. rates of oxygen absorption from the air, and also The second method proposed in the prior art to produce melts which are liquid at tempera for the production of chlorine is a cyclic tWor tures of operation of the various steps of the stage process, involving in the first stage, abr processes, thereby making possible continuous 25 sorption of the in a metal cyclic operation. oxide, whereby the metal oxide is converted to Numerous methods have been proposed in the the chloride, and, in the second stage, the recon prior art for the preparation of oxygen from air. version of the metal chloride to the oxide and chlo These methods may be classified as those involv rine by means of oxygen at a higher temperature. ing physical methods of separation such as lique 30 The “Mond” process is a typical example of such faction followed by fractionation of the liquid air a process in producing only a dilut? chlorine con and those involving chemical methods such as taining gas and having the additional disadvan absorption and desorption of oxygen by chemical tage of the necessity of alternately cooling and oxidation and reduction of solids such as oxides heating a stationary mass in the converter over a of polyvalent metals, the higher oxides of which 3 5 considerable temperature range while changing are reducible by heating at moderately high Over from One stage of the operation to the other, temperatures. One of the earliest commercial resulting in heat losses and inefficient use of the methods of the latter class involved the absorp Converter during the heating and cooling opera tion of oxygen by the lower oxides of barium or tions. As in the case of a more efficient method manganese to form the higher oxides of these 40 for producing oxygen, the present invention sup metals which were then desorbed of oxygen either plies a medium for oxygen absorption and heat at elevated temperature or reduced pressure. transfer thus making possible a continuous cyclic These methods proved cumbersome in practice process for producing chlorine. and in the case of barium oxide (Brin's process) A third process to which my invention is an im required relatively pure air with respect to car 45 portant contribution is that of recovering hydro bon dioxide content. Hence liquefaction methods gen chloride in the form of alkyl halides such as were later adopted. However, liquefaction meth methyl chloride described in detail in the here ods are intrinsically expensive involving costly inabovementioned U. S. Patent 2,407,828. Hydro high pressure refrigeration equipment. The pres gen halides, such as hydrogen chloride, are lib ent invention relates to a chemical method adapt 50 erated in the production of alkyl inter able for continuous production of oxygen from mediates by halogenation of hydrocarbons and in ordinary air by employing melts of copper chlo the conversion of such halides to the final prod rides with alkali metal chlorides in such propor lucts; hence the commercial feasibility of these tions as to give liquid media for maximum rate processes usually depends upon the economical of oxygen absorption. 55 recovery of the acids and their recon

244,828 3 version to the corresponding halide. Prior art 4 m methods have attempted the recovery and recon as methyl chloride, this may be accomplished in version of halogen acids by processes wherein the à sepàtrate Žone by contacting the neutralized oxidation of the acid and the chlorination of oxychloridepressed by the molten equation: mass with as ex methane are carried out simultaneously. For ex ample, it has been suggested that methyl chloride be produced by passing a mixture of methane, hydrogen chloride and air, or oxygen, over a sup As described in detail hereinbelow, I have illus ported copperhalide catalyst. In the use of meth trated my process diagrammatically in Figure ods involving simultaneous oxidation of hydro O wherein is shown the application of the copper chloric acid and chlorination of hydrocarbons, chloride-potassium chloride melts in a process for particularly methane, the yields of chloroneth. converting hydrogen chloride to alkyl chlorides mes are low and considerable hydrogen chloride using copper chloride-potassium chloride melts passes through the converter unchanged and the in Optimum concentration of potassium chloride, chloromethanes are highly diluted with cuprous chloride and capric chloride. The process vapor and air, thus requiring additional and ex 5 incorporates three successive steps wherein the pensive processing to obtain the chloromethanes principal reactions occurring in the steps are ill in purified förii?i. lustrated by Equation 1, Equation 3 and Equation 5 respectively. The first reaction zone is desig A primary object of the present invention is to nated as the preoxidation zone, the next zone is provide melts of copper chloride with alkali metal 20 designated the oxidation-neutralization zone and halides, preferably with potassium chloride, for the final Zone, the chlorination zone, utilization as absorbent media for oxygen in im Since it is desirable to maintain the melt in a proved continuous cyclic processes for the produc liquid state in the operation of a continuous cyclic tion of oxygen, and for the production of chlorine process, the choice of composition of the melt to or chlorinated hydrocarbons from hydrogen chlo 925 be used is determined (i) by the freezing point ride involving an oxidation step. of the melt as affected by change of composition A further object of the invention is to provide relative to proportions of cuprous chloride and melts of the chlorides of copper with potassium cupric chloride in successive steps of the process chloride in such proportions that maximum rates and by the mole percent of potassium chloride in of absorption of oxygen from the air can be ob 30 the melt, (2) by the desired rate of oxidation of taimed at operating temperatures adaptable to the melt, and (3) by the desired rate of chlorina improved methods of producing oxygen, chlorine tion by the melt. . . or chlorinated hydrocarbons. It has been found that potassium chloride as a An additional object of this invention is to third component in admixture with cupric and produce a carrier supported mixture of chlorides 35 cuprous chlorides produces melts of relatively low of copper and potassium chloride in such pro freezing points and other suitable properties, and portions of potassium chloride to copper chlorides hence is a desirable component in such a mixture that the heated mixture of chlorides will show for reducing to continuous cyclic operation proc high rates of oxygen absorption. esses involving the use of these components such Still another object of the invention is to pro 40 as for the production of oxygen, for the oxidation duce oxygen absorption melts of copper chlorides of organic materials, for the production of chlo with potassium chloride in proportions such that rine and for the chlorination of hydrocarbons. said melts may be readily maintained in the liq I have found that in addition to producing rela uld phase in all of the steps and transfer opera tively low freezing pointmelts of copper chlorides, tions in the methods referred to above for pro 45 potassium chloride at optimum concentrations ducing oxygen, chlorine, or chlorinated hydrocar greatly increases the rate of Oxidation of cuprous bonS. chloride in the melt. I have further found that Other and further objects of the invention will these optimum concentrations with respect to be apparent from the description thereof and from rate of Oxidation correspond very closely to mini the appended claims. 50 imum melting compositions of the copper chlo Cuprous chloride may be converted to the ride-potassium chloride mixtures. cupric oxide-cupric chloride complex form by re Potassium chloride occupies a unique position acting the molten chloride with air according to as a third component in regard to freezing point the following equation: depression of the copper chloride Salts. (1) 2CuC+4O2->CuO.CuCl2 55 chloride as a third component does not give a comparable lowering, but a part of the potassium The molten mass containing the complex chloride in the melt can be replaced by sodium "oxychloride' may be treated in succeeding steps chloride or other alkali metal chlorides without to make oxygen, or chlorine or to chlorinate hy appreciably altering the extent of the lowering. drocarbons such as methane. If it is desired to 60 Thus crude potassium chloride containing appre make oxygen, the molten mass is heated in a ciable amounts of other alkali can second step to reconvert the same to cuprous chlo be used, the effect of such impurities being to ride and free oxygen according to the equation: further lower the freezing points. (2) CuO.CuCl2--AH-2CuCl--40 I have found that melts suitable, with respect 35 to both freezing point and rate of oxygen absorp If it is desired to recover hydrogen chloride by. tion contain from 20 to 50 mole percent potassium reconversion to chlorine, the molten mass con chloride, the preferred range of potassium chloa taining oxychloride is contacted with the Waste ride content being from 25 to 45 mole percent. gas containing the hydrogen chloride and reac The basis for the above preferred limits will be tion takes place according to the equations: 70 come clear in the subsequent discussion and by (3) CuO.CuCl2--2HC1->2CuCl2--H2O reference to Figure 2. Cupric chloride forms a complex of the COm (4) 2CuCla--AH-2CuCl--Cla position KCuCl4, with the potassium chloride of If on the other hand it is desirable to utilize the the melt. As a first approximation it can be chlorine directly to produce alkyl chlorides such 75 considered that the melt after it has been used

244,828 6 for chlorination or oxidation will be approxi 50 to 55 mole percent cuprous chloride. Such mately a mixture of of cuprous chloride in . a mellt will be in quid form at - temperatures KCuC. Such a mixture is to be understood as above about 250° C. and the mixture will remain included in the ternary system cuprous chloride, in liquid form even though in the oxidation cupric chloride and potassium chloride. For ex neutralization step, the relative concentration of ample, a mixture consisting of 30 mole. percent cupric chloride to cuprous chloride may change potassium chloride, 15 mole percent cupric chlo from an initial ratio of 15:55 to a ratio as high ride and 55 mole percent cuprous chloride is to as 50:20 since the temperature of the melt mix be considered identical with a mixture consisting ture increases, as a result of the exothermic of 55 moles cuprous chloride, CuCl, and 5 moles O character of the oxidation reaction, to 450° C. or of the complex KaCuCl4 or a mixture containing even 500° C. in that part of the reactor where 78.6 mole percent of cuprous chloride and 21.4 these higher concentrations of cupric chloride mole percent of the complex KaCuCl4. The for predominate. The freezing point of a melt have mation of this complex causes a part of the ing a composition of 50 mole percent cupric cupric chloride to remain practically inactive for . chloride, 20 mole percent cuprous chloride and 30 chlorination as shown in Figure 3 where the rate mole percent potassium chloride is about 430 C. of chlorination of methane in arbitrary units is The above ratios of cupric chloride to cuprous plotted against percent of the copper in the Cupric chloride should not be interpreted as limitations chloride form for a melt containing 30 mole per On the melt composition. In fact, the Only neces cent KC. 20 sary specification for making up the melt for However, it may also be seen from Figure 3 that the chlorination processes is On the ratio of at higher temperatures the said complex begins potassium chloride to copper chlorides, since the to show some activity. For example, the 400 C. ratio of cupric chloride to cuprous chloride in chlorination rate curve may be extrapolated ap the melt changes in use. For example, in the proximately as a straight line to zero chlorina 25 process described below, regardless of whether tion rate at the point where 21.4 mole percent of the starting melt contains substantially all of the copper is cupric chloride which represents the copper chloride in the cupric form or sub the cupric chloride "tied up' as inactive complex, stantially all of the copper chloride in the cuprous K2CuCl4. On the other hand the chlorination form, the range of ratios of cupric chloride to rate curves at higher temperature deviate from a 3. - cuprous chloride present in the melt for on linear relation in the neighborhood of 21.4 per stream operation will assume the same values, cent cupric chloride, the deviation being greater which values will depend spmewhat on the oper the higher the temperature. This shows that the ating conditions. These values of mole ratios complex KaCuCl4 becomes more active at higher of çupric chloride to cuprous chloride for con temperatures as a result of partial thermal de 35 tinuous on strean operation will lie within the composition into free cupric chloride and free range of from about 1:10 to about 10:1. potassium chloride. Therefore, I do not wish to I do not wish to be restricted to the circulation be restricted to operation in the range of percent of the liquid molten - salt mixtures per se since cupric chloride in excess of that required to form the preferred compositions may be absorbed or the complex K2CuCl4. 40 impregnated on suitable inert porous supporting In view of the approximate limitation of activ materials and circulated by any of the Well known ity of cupric chloride by the formation of the “fluid" techniques. Such materials as alumina, complex KCuCl4, I have determined rates of alumina gels, silica gels, aluminarsilica gels, full absorption of oxygen as a function of mole per er's earth, infusorial earth, pumice, kieselguhr, cent of potassium chloride along a line correa 45 etc., may be employed. These carrier materials sponding to mixtures of potassium chloride with may be impregnated with the salt mixtures by KCuCl4. The results are shown in Figure 2 any of the well known methods but preferably wherein the rate of oxidation at 400 C., ex by absorption of the salts from a concentrated pressed in arbitrary units, is plotted against mole aqueous , for example, a concentrated percent of potassium chloride in the melt. From 50 solution of cupric chloride and an alkali metal the curves in Figure 2 it is clear that a maximum chloride such as potassium chloride containing rate exists. Also in Figure 2, are plotted the the preferred ratio 20 to 50 moles of alkali metal allowable ranges of cuprous chloride change as a chloride to 100 moles total of the two salts. function of mole percent potassium chloride at Where the chlorides are supported on inert various temperatures, the range at any point be carriers freezing point considerations are not ing limited on the one hand by the freezing point controlling and hence, any alkali metal chloride of the melt and on the other by the inactivity of may be used to modify the rate of reaction. KCuCl4, which as pointed out before becomes The material after filtration and drying may somewhat active at the higher temperatures. It be crushed. If the impregnated carrier is to be is seen that for temperatures between 300 C. 60 suspended in a gas such as in air for the produc and 450° C. a maximum change in cuprous chlo tion of oxygen as described and claimed in co ride content is possible for melts containing from pending application, Serial No. 548.350. filed 25 to 45 mole percent potassium chloride. It may August 7, 1944, by Edwin Gorin and applicant, thus be seen that the preferred potassium chlo the particle size of the crushed impregnated ride content with respect to both rate of oxygen 65 carrier so used will be within the range of 10 absorption and freezing point is from about 25 mesh and 10 micron size, preferably within the to 45 mole percent with the outer limits from range of 30 mesh and 50 micron material. The about 20 to about 50 mole percent potassium impregnated carrier may be used for chlorin chloride. tion or if it is to be used for oxygen absorption as In making up my copper chloride-potassium, described above, the cupric chloride content is chloride melt, I may introduce fresh melt having. first partially reduced to cuprous chloride, for a composition approximately 30 to 35 mole per example, by contacting with a hydrocarbon at cent potassium chloride, and 70 to 65 mole per temperatures within the range of 400° C. to 500 cent chlorides of copper of which approximately C. By this procedure the above described melt 15 mole percent consists of cupric chloride and 75 is formed in situ. The total amount of chloride 7 impregnated on the carrier by the above method thereby control the degree of oxidation in pre will be within the range of from about 20% to oxidizer 2 and also to some extent control the 65% by weight of the impregnated product, pref temperature of the air entering tower T. I pre erably from about 30% to about 50% by weight. fer to oxidize the melt in tower f2 to approxi The amount of mixed chlorides on the support mately the of the oxychloride and cop should not be too high to retain the free flowing per Oxide in the melt. This amounts to 1 to 8 characteristics of the impregnated powdered mole percent of the total copper salt or approxi solid at temperatures above the of mately 3 to 30% of the total conversion of cu the supported mixture of chlorides. . . prous chloride to cupric chloride per pass In order to illustrate specifically the manner through the oxidation zones. in which my novel salt composition may be pre The oxygen enriched melt becomes cooled pared for use as a carrier impregnated reactant, Somewhat as it passes through tower 2 due to 0.70 mol of cupric chloride, and 0.30 mole of Contact with cold air and limited extent of oxi potassium chloride were dissolved in water to dation therein, and hence cooler 9 may not be form 250 cubic centimeters of solution. The necessary for COoling the melt as it leaves tower solution was added to finely pulverized infusorial 2 through line 20 in which case the valve in by earth to form a slurry. The material was filtered pass line 2 is opened and the valve in line 20 and the solid was dried at 150° C. and pulverized. is closed whereby melt is sent directly to the The anhydrous powder contained 23.6 weight per Oxidizer-neutralizer tower T. In case cooler 9 cent of cupric chloride salt and 5.6 weight per 20 is used, the hot melt may be heat exchanged cent of potassium chloride. The impregnated with hydrocarbon feed to chlorinator 24 intro powder was heated to 500 C. without agglomera duced to cooler 9 through line 25, thereby con tion and was shown to react in a manner serving heat of oxidation for use in the chlorina analogous to a 30 mole percent potassium chlo tion step. If, on the other hand, it is desirable ride melt except for a greatly accelerated rate to remove heat from the system, cooling fluid of reaction due to the extent of exposed surface. may be introduced to cooler (9 via lines 3 and The cupric chloride was partially reduced in situ 25 and removed from cooler 9 via lines 39 by contacting the mass with methane at about and 32. 410° C. and the resulting powder was found to In packed tower the heated melt is con absorb oxygen rapidly from a stream of air in a 30 tacted with heated air leaving tower 2 through temperature range from 300° C. to 450° C. After line 5 and introduced to tower at a multi contacting the oxide containing powder with plicity of points through valved lines 6a, 6b hydrogen chloride the powder was used to chlo and 6c. Hydrogen chloride in amounts of about rinate methane in the temperature range from four moles per mole of total oxygen absorbed by 350° C. to 525 C. The rate of chlorination was 35 the melt, in the form of of at rapid at temperatures above about 375 C. least 20% concentration but preferably more In order to illustrate the manner in which the concentrated, in a hydrogen chloride equivalent improved copper chloride oxygen absorbent melts quantity, is introduced at a multiplicity of points may be used, the following description of an near the bottom of tower T through line 34 a diabatic process for the chlorination of methane 4) provided with a conventional compressor. The is given in connection with Figure 1. mixture of rising air and hydrogen chloride re Referring to Figure 1, a molten mixture con act with the descending melt to produce at the sisting of about 30 mole percent potassium chlo tower exit a melt of maximum cupric chloride ride, 55 mole percent of cuprous chloride and 15 Content. mole percent cupric chloride is introduced at a As stated above, the melt issuing from the pre temperature within the range of from about 350 oxidizer 2 is saturated with respect to oxide C. to about 400° C. through line O and pump content of the melt which progressively dimin f to packed preoxidizer tower f2 where it is ishes in passing down through tower as in contacted with air introduced to tower 2 by creased concentration of hydrogen chloride is means of compressor f4 in line 3. I prefer to encountered by the melt. The Oxide content is operate the preoxidation tower at pressures above finally diminished to a very low value at the atmospheric, pressures as high as 25 or 35 at bottom of reaction tower 7 in the zone of high mospheres being suitable for this operation. est hydrogen chloride concentration. This con The function of the preoxidation step is to dition prevents contamination of the chlorinated produce a part of the unstable oxychloride, 5 5 product with Water vapor formed by neutraliza CuO'CuCl2 in a Zone ahead of the oxidation tion. The water vapor is eliminated from tower neutralization step in order to supply an absorb along with the oxygen depleted air through ent for any hydrogen chloride present near the line 35. The temperature of the melt in tower top of the oxidation-neutralization tower de ranges from a maximum of 375 C. at the scribed below. Fresh cuprous chloride melt or 60 top of the tower to a range of 4.25° C. to 525 C. recycle cuprous chloride melt containing either as the melt leaves the tower through line 36 free cupric chloride or the complex KaCuCl4 con leading to the top of chlorination tower 24. If ing in contact with water vapor in the effluent desired, the melt may be heated by any suitable gas from the oxidation-neutralization tower means, as by a furnace (not shown), after leav hydrolyzes to a certain extent to form HCl. ing tower via line 36, before introduction to Hence, recycle cuprous chloride is first partly chlorination tower 24. Loss of HC in the over converted to the oxychloride in the preoxidation head via line 35 from tower f is minimized by tower before entering tower f. An additional preconversion of cuprous chloride in the melt in function of the preoxidizer is to heat up the tower (2 to the oxychloride which absorbs any main air stream passing as overhead from pre excess hydrogen chloride reaching the top of oxidizer 2 through lines 5 and valved lines 6a, tower f. If desired, the traces of HCl and vola 6b and lic to the oxidizer-neutralizer . By tilized melt loss through line 35 may be recovered the proper adjustment of the valves in line 3 by condensing a small fraction, for example, 2 and by-pass line f, I may by-pass the preoxi or 3 percent of the steam in the effluent stream dizer 2 with a part of the necessary air, and 75 by means of a chilled packed tower (not shown), 244,828 O the condensate being returned through the EC tion rates and hence, reduced size of Syge as feed line 34. This effluent stream may also be sorber, i do not wish to be linited to such lise Sed for preheating the methane feed to tower of the melits since they can ke used With egal 26 or as a source of additional heat or power. advantage in an analogous process for the pror The operation in tower is preferably carried duction of free chlorine, for the production of out at pressures in excess of atmospheric, free oxygen, or for the oxidation of organic ma though preferably at somewhat lower than the terials or in any process in which 8, guid or operating pressure of preoxidation tower 2. carrier adsorbed melt is used to absorb oxygen. In packed tower 24 the melt, rich in cupric The foregoing description has been made chloride, contacts countercurrently methane was rather detailed for clearness of understanding pors introduced at the bottom of the tower via only, and no unnecessary limitations should be line 28, compressor 3 and valved line 38 and is understood therefron, but the appended claim thereby converted to a cuprous chloride rich net should be construed as broadly es permissible di with simultaneous formation of a mixture of view of the prior art. chloromethanes, predominantly methyl chloride. clain: : By proper adjustment of the valves in lines 38, A composition of matter consisting essentially 39, 40, 3 and 32 the methane feed to chlorina of a melt of potassium chloride, cupsous chloride tion tower 24 may be used as a cooling means for preoxidized melt in cooler 9, or the methane and cupric chloride said potassium chloride bes may be used as cooling means for overhead ing present in amounts within the range of from product from tower 24 in exchanger 4. The about 25 mole percent to about 45 Inole percent, temperature of the met in chlorination tower said cuprous chloride being present in amounts 24 will vary from a range of 4.25° C. to 525 C. at within the range of from about 5 inole percent to the top of the tower to 375 C. to 425 C. at the about 65 mole percent and said cupric chloride exit from the tower in line 42 depending on the being present in amounts within the range of extent of preheating of the methane feed. The frompercent. about 10 mole percent to about 8 a.s.le pressure maintained in tower 28 is usually some What less than the pressure in tower 7. Super CELES: A, SONANA, atmospheric pressures are preferred although tower 24 may be operated at atmospheric pres REFERBERICES, GËTE: sure. The products of the reaction of the hy 80 The following references are of record in the drocarbon with the cupric chloride melt in tower file of this patent: 26 are chiefly the chlorohydrocarbons such as chloromethanes and hydrogen chloride a mix UNITED STATES PATENTS ture of which products is taken overhead via Number Nare DS8 line 33 to a fractionation system for further ? 2,206.399 GrosWenor ------July 2, 1940 processing. In tower 24 the melt is converted 2,280,683 -----ThOInBS' ?? --? ???????? .??? ,21 1942 from a high content of cupric-low content cus prous chloride melt to a low cupric chloride-high FOR3GN PASSES cuprous. chloride melt which is recycled to pre 60 Number Country Date oxidation tower 2 via lines 42 and 0 and pump 3,171 Great Britain ------1863 ... I prefer to maintain a liquid level of melt 214,293 Great Britain ------Apr. 24, 1924 in towers 2, and 24 which I accomplish by 197,955 Germany ------June 3, 1906 ??ans of float control valves in lines 20, 86 and OTHER REFERENCES While I have described an essentially adiabatic é5 "Sulfuric Acid and Alkali,' ange, voluzne , process for making chlorinated hydrocarbons Gurney and Jackson, London, 1911, pages 438-443, utilizing my copper chloride-potassium chloride 451,489? melts in a manner to obtain improved oxida