Patented Apr. 9, 1946 2,398,179 UNITED STATES PATENT OFFICE. P MANUFACTURE OF ETHYL CHLoRIDE Eugen Gottfried Galitzenstein, London, and Cyril Woolf, Finchley, London, England, assign ors to The Distillers Company Limited, Edin burg, Scotland, a British company No Drawing. Application March 9, 1944, Serial No. 525,758. In Great Britain December 28, 1942 20 Claims. (CI, 260-652) It is known that ethyl chloride is formed when densed out. The yield of pure ethylchloride, ob potassium or barium salts of ethyl sulphuric acid tained over a period often hours, was 102 grams are treated with hydrogen chloride (Berichte der or 93 per cent of the theory. Deutschen Chemischen Gesellschaft 1878, 11, 1929). In British specification No. 370,211 there Eacample II is described a process in which ethyl chloride is Into a stirred mixture of 220 grams diethylsul produced when ethyl Sulphuric acid is caused to - phate, 36 grams sulphuric acid (98 per cent) and . react with a qieous hydrochloric acid at tempera 6 grams bismuth oxide, dry hydrogen chloride tures exceeding 100° C. and at elevated pressures was introduced at the rate of about 6 grams per Such as 24 atmospheres. w O hour whilst maintaining a temperature of 80° C. We have found that ethyl chloride can be pro in the reaction liquid. The escaping gases were duced Satisfactorily according to the present in washed with water and then with milk of lime, vention by reacting gaseous hydrogen chloride dried with calcium chloride and the ethyl chlo with preformed sulphuric esters of ethyl alcohol ride condensed out. In 20 hours 163 grams of in the presence of a compound of antimony, bis practically pure ethylchloride were collected, the nuth or tin as catalyst at temperatures between yield being 90 per cent of the theory. 40' and iO C. The chlorides, oxides, sulphates or carbonates of antimony, bismuth and tin may Eacample III be used. . A stirred mixture of 105 grams diethylsulphate, The reaction between ethyl hydrogen sulphate 20 70 grams sulphuric acid (100 per cent) and 17 and hydrogen chloride proceeds according to the grams anhydrous tin tetrachloride was treated equation: with a stream of about 7 grams per hour of dry hydrogen chloride at a temperature of 98°C. The (1) Cahs.HSO4-HCl=CasCl--H2SO4 escaping vapours were led through a fractionat and can be carried out at normal pressure. 2 5 ing Column at the top of which a vapour tem Instead of ethyl Sulphuric acid, diethyl Sulphate perature of 13 C. was maintained by means of a can be used. We have found that when ethyl reflux condenser. After washing and drying eth chloride is produced by the interaction of hydro ylchloride was condensed at the rate of 12 grams gen chloride and diethyl sulphate in the presence per hour. of compounds of antimony, bismuth or tin, the 30 It will be inferred from Equations 2 and 1 initiation of the reaction is facilitated by the that on completion of the reaction between the presence of Some free sulphuric acid in the reac esters of sulphuric acid and hydrogen chloride, tion mixture at the Commencement of the reac free sulphuric acid is present together with the tion. The probable function of this free sul metal compounds. We have found that the spent phuric acid is to cause the formation of ethyl 35 liquids resulting from the reaction between ethyl sulphuric acid according to the equattion: . sulphuricesters and hydrogen chloride have the power of absorbing ethylene thus reforming the original sulphuric acid esters. The reformed es The following examples illustrate the process ters are capable of reacting again with hydrogen of the invention as a batch process: 40 chloride to produce ethylchloride without the Eacample I necessity of further addition of compounds of antimony, bismuth and tin. A stirring fiask was charged with 214 grams Accordingly, therefore, our invention includes ethylsulphuric acid. 14 grams of anhydrous an a process for the manufacture of ethyl chloride timony trichloride were added and dry hydrogen 45 from ethylene. The process consists of a number chloride was then introduced at the rate of about of cycles, each cycle comprising two stages. In 8 grams per hour whilst maintaining the liquid the first stage, ethylene is absorbed by sulphuric at a temperature of 90° C. Stirring was con acid. Compounds of antimony, bismuth or tin titled throughout the Operation. The vapours are added to the resulting liquid and the second escaping from the stirring flask consisted of ethyl 50 stage of the process consists in reacting the mix chloride accompanied by Some excess of hydrogen ture with hydrogen chloride to produce ethyl chlo chloride which was removed from the ethyl chlo ride. These two stages comprise the first cycle. ride by Washing with Water and then with Caustic In the first stage of the second cycle, ethylene is soda solution. The vapours of ethyl chloride again absorbed following which, hydrogen chlo were dried with calcium chloride and then Conn 55 ride is again passed through the liquid reaction 2 2,898,179 medium, which still contains the catalyst remain liquid showed an increase in Weight of 47 grams ing from the first cycle, producing ethyl chloride: corresponding to an absorption of 0.9 no of this constitutes the second stage of the second ethylene per mol of sulphuric acid. The ten cycle. Further cycles are the same as the second perature was then raised to 90' C., hydrogen chlo cycle. s ride was introduced and ethylchloride condensed We prefer to carry, out our process in a sub out of the effuent gases. When the production stantially anhydrous medium using sulphuric acid /rate of ethylchloride began to decrease, the hydro of between 100 per cent and 95 percent by Weight. gen chloride stream was stopped, the temperature We have found it to be advantageous in the lowered to 70° C. and ethylene introduced (begin stages of ethylene absorption to introduce ethyl ning a second cycle of Operations) and the ab ene until the concentration of ethyl groups pres sorption of ethylene was continued until an in ent (in the form of the sulphuric esters of ethyl crease in weight of 38 grams had occurred thus alcohol) has reached between 0.7 to 12 mols per again bringing the total amount of ethyl groups mol of sulphuric acid. Such mixtures of diethyl present to 0.9 mol per mol of Sulphuric acid. sulphate, ethylsulphuric acid and sulphuric acid s The Subsequent introduction of hydrogen chloride have been found to be the most suitable for the was carried out at 90° C. Further cycles followed production of ethylchloride. Furthermore we in a way similar to the last cycle. After a Work have found it unnecessary to continue the hy ing time of 150 hours the yield of ethylchloride drogen chloride introduction to the point of com produced based on ethylene absorbed amounted pletion of the reaction: we prefer to stop the flow 20 to 88 per cent of the theory. of hydrogen chloride when the rate of ethylchlo Instead of pure ethylene, gas mixtures contain ride production slackens off. This generally oc ing ethylene, e. g. mixtures of ethylene and paraf curs when the concentration of ethyl groups has fin hydrocarbons; can be used. We have found it fallen to the neighbourhood of 0.25 mol per mol advantageous to employ elevated pressure in the of sulphuric acid present in the reaction medium. 92.5 ethylene absorption stage when using ethylene By leaving some unreacted ethyl groups in the so admixed with other gases. The corresponding lution, the subsequent absorption of ethylene is stages of ethylchloride production may be car enhanced, as is already known from prior British ried out in a separate vessel and at ordinary pres specification No. 221,512. sure. Previous processes (e. g. that described in The following examples illustrate the process of 30 United States specification No. 2,125,284) relating the invention as a Continuous process consisting to the direct reaction between hydrogen chloride of a number of successive cycles. and gas mixtures containing ethylene have proved to be technically unsatisfactory as the presence of Eacaraple IV inert gaseous substances depresses the rate of for A stirring vessel was charged with 180 grams mation of ethylchloride and gives rise to difficul sulphuric acid (98 per cent) and 12 grams an ties in the recovery of the diluted ethylchloride. hydrous bismuth chloride. The contents of the However, the ethylchloride obtained by our proc vessel were stirred and maintained at 70° C. dur ess, is contaminated only with hydrogen chloride, ing the whole operation. Dry ethylene was intro which is readily removed. duced at the rate of 11-12 grams per hour for 4 40 Instead of a stirring vessel, other suitable de hours. The ethylene supply was then cut of and vices can be employed for alternately contacting dry hydrogen chloride introduced at the rate of the liquid reaction medium with ethylene and about 9 grams per hour to start the production of with hydrogen chloride. For instance the two ethylchloride. When the rate of formation of gases may be alternately passed into a coil sys ethylchloride dropped below a figure of 6 grams tem through which the liquid reaction medium is per hour the introduction of hydrogen chloride circulated at high speed with aid of a pump. - was cut off, the passage of ethylene was restarted The experiments on which the present inven and the second and subsequent cycles carried out. tion is based proved that the presence of Con The results of the entire operation are Sun pounds of antimony, bismuth or tin is essential marized in the following table: 50 for the manufacture of ethylchloride from hydro gen chloride and the ethyl esters of sulphuric acid. Ethylene No ethylchloride production could be obtained Ethylene absorp Ethylt ethylchloES absorbed tion chloride ride pro- Tief when working according to United States specif period produced duction cation No. 2,284,467 in which there is described period the production of alkylchlorides by contacting an

Grains. Hot Grams outs Hours olefine and hydrogen chloride with sulphuric acid 4. 5% 9 (97 to 100 per cent) at atmospheric pressure and 33 54 9% 3. 34 1033 at a temperature between room temperature and 32 1. the freezing point of sulphuric acid. 3. 0. 11 What we claim is: 2 12% 1. A process for the manufacture of ethyl chlo 2 ride which comprises reacting substantially an 2 hydrous gaseous hydrogen chloride with a sub 41 89 10 stantially anhydrous preformed sulphuric ester 85 of ethyl alcohol in the presence of free sulphuric The yield of ethyl chloride based on ethylene acid of a concentration of 95% to 100% and in absorbed was 94 per cent of the theory. The re the presence of a catalyst of the class consist action liquid was still active after the tenth cycle. ing of compounds of antimony, tin and bismuth 70 at a temperature between 40 C. and 110 C. Eacample V 2. A process according to claim 1 wherein said 183 grams of sulphuric acid (100 per cent) con sulphuric ester is ethylhydrogen sulphate. taining 12 grams anhydrous antimony trichloride 3. A process according to claim 1 wherein said were heated to 70° C. and ethylene introduced sulphuric ester is diethyl sulphate. whilst stirring until the weight of the reaction 5 4. A process according to claim 1 wherein a 3.89879 3. mixture of diethyl sulphate and stgauric acid is wherein the ethylene mixed with inert gas is fed employed. under superatinospheric pressure. 5. A process according to clair wherein said 16. A continuous process for the manufacture preformed sulphuric ester contains ethyl groups of ethyl chloride which comprises alternate stages to a value between 0.7 3rd .2 nois per mol of 5 of ethylene feed into sulphuric acid of a concen sugihuric &cid. tration of 95% to 100% containing a catalyst of 6. A process according to claim wherein the the class consisting of compounds of antimony, feed of hydrogen chloride is stopped when the tin and bismuth at a temperature of about 70° C. content of ethyl groups in the reaction qugi has and gaseous substantially anhydrous hydrogen failer to a waite in the eigbo riod of .25 ro O chloride feed into the sulphuric ester-sulphuric perino of Suipitric scid. acid mixture thereby produced at a temperature . A process for the Ethatufacture of ethyl cho of about 90° C. ride which corrprises reacting sustantially al 7. A continuous process for the manufacture hydrous gaseous hydroger chloride Witti. 8 Sle of ethyl chloride which comprises absorbing eth stantially anhydrous preformed sulph tie ester s ylene in Silphuric acid of a concentration of 95 of ethy in the presence of free sphuric acid to 100%, adding a catalyst of the class consisting of a concentration of 95% to 200% and alcoho of compounds of antimony, tin and bismuth, re iri, the presence of a catalyst of the eiass consist acting the resulting sulphuric ester-Sulphuric ing of compounds of antisony, tin and bismuth acid mixture with Substantially anhydrous gase at a temperature between 40 C. and 30 C, until 20 ous hydrogen chloride at a temperature of 40 to the cerent of ethyl grougs is he reaction Sigid 10° C., continuously distilling off formed ethyl has failer to a value in the neighborhood of 9.25 chloride and returning the sulphuric acid-con moi per no of sulphuric acid, stopping the feed: taining residue to the ethylene absorption stage. of hydrogen chloride, feeding ethylene into the 18. A continuous process for the manufacture reactio; lictiid to regeneate (E& sail sphatic 23. of ethyl chloride which comprises absorbing eth ester-Sulphitric acid Enixture & irid hereafter re ylene in Sulphuric acid of a concentration of 95 starting the feed of hydroger chloride. to 100%, adding a catalyst of the class consisting 3. A process &ccording G claix. whereir the of compounds of antimony, tin and bismuth, re feed of ethylete is stopped ge; the coiter, of acting the resulting Sulphuric ester-sulphuric ethyl groups in the eactic liquit as reached 3. acid. Enixture with substantially anhydrous gase a value between 0.7 and i.2 Eto's pex ino) of sui ots hydrogen chioride at substantially atmos phulic acid. pheric pressure at a temperature of 40° to 0° 9. i. process 3Ccording to clair Wherei She C., coStinuously distring of formed ethyl cho feed of ethylene is stopped wire the context of ride &nd returning the sulphuric acid-containing ety groups in the reactic litici has reached residue to the ethylene absorption stage. a waite between O. aidi .2 nois per no of st 29. A continuous process for the manufacture phic acid aid the feedi of hydrogen chioidie of ethyl chioride whichi comprises absorbing eth is stopped where the criteit of ety groups in yieize in Sulphuric scid of a concentration of 95 the eactio; clid 8s gaiei, to a value in the to 60%, adding a catalyst of the class consisting Reigh curhood of 0.25 to ge!' go of Suipitric of coerigotrids of 328irony, tin and bismuth, acidi. - reacting the resulting sulphuric ester-suiphuric 6, & co; i:::CS grocess for 8.2e Iri&ntiagtire &cid mixture with substantially anhydrous gase of etyl chloside which comprises aeriae g;3ges Otis hydrogen chloridie at substantially atmos of ethylene seed into Suipitric acid of 8 cc):ce:- pheric pressure at a temperature of 70° to 90° tr8tion os 95% to i00% COE airing a Cats:ySt. 45 C. Continuously distiling off formed ethyl chlo cf the class consisting of coligo Eicis of artificity, ridie and returning the sulphuric acid-containing ti; &lid bisiniti and gaseous Sustaitially 8 residue to the ethere absorption stage. Sciots lydireger chorida feed into the Sui 20. A continucus process for the manufacture pitric ester-stylphuric. &cid sixte thereby pro of ethyi chloride which comprises introducing duced at a teiperatuse of 40 C. to 0 C. 5. ethylene into 95 to .00% sulphuric acid, contain ii. A. contiguous process according to claim. () ing 8 catalyst of tire class consisting of coin wherei, the terpe'8:3e (if (i.e. "eaction liquid pct:tidis of Eritroy, tir and bismitti, in an ab digging She stage oi ethylise feedi is over than Sorbet, withdrawing front said absorber a reac during the stage of fe&ciig Sdrogen cioride, tion product, consisting of ethyl sulphurie esters 12. A. continuous process accordirig (g cisir C 55 3rd Siph Eric acid, containing between 0. Inoi Wherein, the stage of feeding etiye is is ext 2nd 2 mols of ethyl groups per no of sulph tric rated when the reaction liquid cottairs etity: acid and introducing it to a reactor, introducing groups to a value betwee: (...? ≠ i.2 nois per Substantity anhydrous gaseous hydroger cho Itoi of Stiphilic acid. ridie into said reaction product, maintaining a i3. A. continuous process according to claim. iC temperature in said reactor of between 40° and Wherein the stage of feeding gaseous hydrogen. 60 if 0 C., continuously withdrawing ethyl chloride chloride is tening;ess when the reaction liquid therefron and continuously recycling to said ab costairs etyl groups to a w8.itze is the eigh Sorber the partially exhausted resction product, bouillood of 0.25 re ge; no gi stiptic acidi. containing ethyi groups in the ratics of about 0.25 ié. A continois process according to clair, G no per no of sulphuric acid. wieieir the ethylene feed is a mixtee of ethy 65 ele & Eid S.I. iiiet gas. EGEN GOEIERED GALZENSN. i5. A continuous process Becording to cisir i0. CYRIE, woo F.