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AN ABSTRACT OF THE THESIS OF

j-9jç for the- S.___in_ahenaity-___ (Nam) (Degree) (Majrr) Date T1esjs _____ Tit1e_A tud oLtbe_E1 trQ an

-

Abstract Approved: (jor Professor)

An investigation hes been niade of the electrolysis of an aqueous solution of hydrochloric . in the presence of ethylene chiorohydrin In an electrolytic diaphra cell into which ethyiene was being intro ducod at a rate equal to its rate of absorption into the electrolyte.

Ethylene chlorohdrin has been prepared in tho cell described.

A possible reactIon niechanisni was proposed.

Th3 variables considered over a limited range wore hydrochloric acid , ethylene chloro hydrin concen:ratIon, and current density at the anode.

Evidence shows neither the concentration of the hydrochloric acid or the concentration of ethylene hlorohydrIn Is independent of the other in liniit

Ing the concentration of eth . ylene ehlorohydrin att1n able before the formation of ethylene sets in extensively.

Higher current. densities favor higher rates of electrolytic oxidation of ethylene. A STUDY OP TEE ELECTROLYSIS OP AN AQUEOUS SOLUTION OP HYDROCHLORIC ACID IN TEE PRESENCE OF ETHYLENE CHLOROHYDRIN AND ETHYLENE by

WILLIAM EARL ROAE

A THESIS submitted. to the

OREGON STATE COLLEGE

in partial fulfillment of the requirements for the degree of

MASTER OF SCIENCE May 1942 PPPfl1T1

In Charge of Major

Chairman of School Grad.uate Committee ACITOVvIEDGMEET

The author is deep1 grateful for the help and. suggestions of G. C. Ware and. G. W. Gleeson.

An appreciation is due the Department of Chemical Engineering, Oregon State College, which supplied. sorne of the materials used in this investigation, and. the Department of Chemistr3, Oregon State College, which supplied the necessarì apparatus and chemicals.

W. E. R. TABLE OP CONTENT8

Page

Introductiou ...... , ...... i

Apparatuo . . . . . s . e s I I I S I I I S a

Operational Prooed.ure ...... 10 i n.aiytioal Prooednre ...... , . . . . i 12

D180U8810]2 ...... , ...... 14 P late I ...... ,...... 18 Plate I]: ...... 19 Plate III ...... ,...... 20

Oonolusion . . , ...... s s . . i i . s s s . . s s 21

Bibliography ...... 22

Appendix ...... 23 A STUDY OP THE ELECTROLYSIS OP AN AQUEOUS SOLUTION OP HYDROCHLORIC ACID IN THE PRESENCE Q1' TYLENP CEIOROHYDRIN MID ETHYLENE

INTRODtJCTI ON

Ethylene ohiorohydrin is an important building block in today's synthetic organic . It finds use as an intermediate in the production of ethylene glycol, , and. their derivatives, anesthetics, extraction solvents, hardenable resins, etc. Although Wurtz (1) discovered ethylene chiorohydrin in

1b59, the literature has failed to reveal much about its commercial production, the only method of technical signif- icance being the interaction of ethylene with or water. Ethylene chiorohydrin is produced by the addition of hypoohlorou acid to ethylene. Hypochiorous acid. has been used. in the form of calcium hypoohiorite (2), sodium hypo- chlorite (3), or aqueous hypochiorous acid. prepared by the

(1) urtz, Ann., 110, 125, (1859); Ellis, Carleton, The Chemistry of PetroTm Derivatives, The Chemical CataT3 Co., Inc., New York, (1934); Carius, Ann., , 197, (1863).

(2) Prahm, E. D. G., Reo. Tray. Onim., 50, 261-7, (1931); O. A., 25, 2690, (1931); Norris, O. A., 13, 2740, (1919).

(3) Prahm, E. D. G., loo. cit.; Essex & Ward, U. S. Pat. 1,594,608; C. A., 20, 3170, (1926). 2 interaction of chlorine and. water (4). Irvine and. Haworth

(5) proposed. the use o± a 0.1% cupric chloride solution as a catalyst. If ethylene is passed. into an electrolytic cell where a solution is being electro- lyzed., ethylene ohiorohydrin is formed (6). Goinberg (7), in his extensive investigation of the system of chlorine, water, and. ethylene, in speaking of the reacti on

EOH + 012 HOOl + HOi + + 0H2:0H2 0H2:0H2

'i. 002: 0H201 HOCH2 0H201 states, "...... the principal factor likely to determine the ratio of ethylene chloride to chiorohydrin must lie, after all, in the relative velocities of the two reactions, ...... between ethylene and chlorine on the one hand, and. between ethylene and h,ypoohlorous acid on the other. In case the second reaction occurs with greater velocity than the first, then we should be dealing with a

(4) Prahm E. D. G. loo. cit.; Gornberg, M., J. . 0. 5., ±., 1414, f1919); O. A., 13, 2369, (1919).

(5) frahm, E. D. G., 1cc. cit.; Irvine & Hawortb, U. S. Pat. 1,496,675; 0. A., 18, 2345, (1924).

(6) McElroy, K. P., U. 8. Pat. 1,253,617; 0. A., 12, 703, (1918); Haddan, R., Brit. Pat. 140,831; J. Soc. Chem. md., 39, 426, (1920).

(7) Goniberg, M., J. A. 0. 5., 41, 1414, (1919). ca$e of mobile eq,nilibrium, and. the principal product would be chlorohydrin, ...... provided that care be taken to maintain stirring, so that ethylene reacts on1i with the chlorine in solution and not with the gaseous chlorine. Experinents proved that such is actualli the ease." Ex- periniental evidence show$ that the formation off ethilene chlorohydrin in this reaction continues practically un- hindered. up to chlorohyd.rin of 7 to 8% (8), above which concentration the formation of diohiorides and higher proceeds at a rapidly increasing rate. Attempts to remove the h,ydrochloric acid Îormed in the reaction by the addition of calcium or retards the formation of ohlorobydrin. Removal of the chloride by precipitation methods has, in some instances, nearly stopped the formation of the chlorides, leading investigators to believe that the chloride concentration is the controlling factor in causing these undesirable side reactions (9). Shilov (10) states that the ion acte as a catalyst in the formation of ethylene chiorohydrin.

(8) Gomberg, M., loo. cit.; Bozza & Marnoli, Giori. Ohim. md. e Applicata, 12, 283-92, (1930); Gleeson, G. W., Private Ooiumunication, (1942).

(9) Gleeson, G. W., Private Communication, (1941).

(lo) Shilov, E. A., J. Chem. md.. (Moscow), 5, 1273-6, (1928); 0. A., 23, 2973, (1929). Frahm (ii) refutes the theor3 of the direct addition of hypochlorous acid. to ethi1ene by stating the reaction as an oxidation of ethy1ene to ethylene oxide followed by addition of hydrochloric acid to form ethi1ene cillero- hydrin. He supports his theory by the fact that formation of ethylene chlorohd.rin is catalyzed by copper, , cobalt, and salts which also accelerate the decompo- sition of hypochiorous acid into oxygen and hydrochloric acid. further support is given by the formation of both isobutylene oxide and trimethy]. carbine]. by passage of isobutylene into a solution of iodine and. potassium iodide

(12). If this be the case, then any reaction, chemical or electrolytic, which oxidizes ethylene to ethylene oxide should, in the presence of hydrochloric acid, yield ethyl- ene chlorohyd.rin, other factors permitting. owever, in. aqueous solutions of hydrochloric acid. ethylene glycol is the product of the hydrolysis of ethylene oxide.

omberg (7) indicates that ethylene chiorohydrin in concentrations up to i normal is of least influence in limiting the attainable concentration of ethylene choro- hydrin, and. hydrochloric acid up to 2 normal concentration does not hinder the exclusive formation of ethylene chioro-

(li) 'rahm, E. D. G., loo. cit.; C. A., 25, 2690, (1931).

(12) B'rahm, E. D. G., loe. cit.; Pogorzelski, Chem. Zentr., I, 797, (1905). hrin, but 2 nornial hroeh1oric acid in the presence of 3% eth3lene chlorohydxin, or a nornial concentration of each simu1taneous1 present favors the formation of ethylene chloride rather than ethylene chiorohydrin. Bozza and

Marnoli (is) state that the action of chlorine on ethylene ohlorohydrin becomes appreciable only when the concentra- tion of the latter becomes one molar, and that in the presence of pure hypoohiorous acid the velocity of the chiorohydrin forming reaction is independent of the con- centration of the acid. over a wide range.

It is with these facts in mind that an investigation of the electrolysis of an aqueous solution of hydrochloric acid and. ethylene chlorohyd.rin in the presence of ethylene has been carried out, with the intention of obtaining evi- dence substantiating, or not substantiating some of these statements, and. possibly suggesting a process whereby the commercial production of ethylene ehlorohydrin in an elec- trolytic cell might be feasible.

(13) Bozza & Mamoli, Giorn. Chini, md. e Applicata, 12, 283-92, (1930); Brit. Chem. Abs., A, 1269, (1930); 11Ts, Carleton, loe. cit., 489. APPARLTUS

The electrolysis was carried, out in a cell designed.

with the following intentions; separation of anolyte and

catholyte, removal of hydrogen gas from the cathode,

sealing against gas loss in the anode compartment, re-

circulation of ethylene ana chlorine, thorough mixing of

ethylene with anolyte, temperature control, and, low,

variable current density.

The cell, as shown in figure 1, consisted. of an 800 cc

pyrex beaker (a) of dimensions approximately 6 x

covered with a glued-up cork stopper (b) of proper dimen-

, a ])JT sions 3" x porous cup diaphragm (e) , a cathode

cooling coil (d) , a wire spiral cathode (e) , a

four inch cylindrical platinum screen anode (f) of one inch

diameter, a gas recirculation pump and. stirrer (g) eq,uippeö. with a seal (h), an anode cooling coil (i), an

ethylene inlet and sampling opening (j), a hydrogen outlet

(k) , and. a thermometer (i). ,,s an added. precaution against gas leakage, the cork cover was held. on with heavy rubber bands said the whole cover sealed with paraffin.

The ethylene gas was supplied, to the celi under a slight from a twelve liter gas reservoir. The gas was forced into the cell by a small and. nearly constant hydrostatic pressure supplied by an automatic valve ar- Isvel

4

Iectrolytic Cell

fig. i rangement (shown in figure 2) sensitive to pressure changes

of one millimeter of mercury.

The stirrer and gas recirculation pump was desigûed. with the purpose in mind o± rapid circulation of the anolyte past the anode combined with a maximum distribution of ethy1ene in bubbles of minimum size, thus keeping the solution saturated with ethylene and providing a maximum liquid-gas interface. The stirrer is shown in figure 3.

The current for electrolysis was supplied by a 28 volt generator with a series bank of twelve storage cells floating on the line.

The schematic diagram of the complete setup is shown in figure 4. II/I f mf

T. gc*c L- ¡ r.

£%t+ r

t$ plo.iStSr

Ii ti iL

4 OPERATIONAL PROCEDURE

The nethod. of carrying out this research was to introduoe into the electrolytic cell 650 cc of solution of the proper pred.eterinined constituents and concentrations, then to sot the apparatus in operation ana make the neoes- sary analyses at aefinite intervals of time. The variable most difficult to control was the current strength. Due to variations in the resistance of the cell during electrolysis the total current passing through the cell fluctuated ± 0.1 ampere, making a possible total error of around 4% in the number of ampere hours of electrolysis. Closer control would necessitate the use of a coulonieter. Due to the construction of the cell any variations in current density were made by changing the current rather than the anode area. It is not known what effect the variation of current concentration thus incurred has upon the mechanism of the cell reaction. In all the runs made the temperature of the anolyte was maintained at 2OC. t 2. No attempts were made to determine the effect of varying the operational tempera- ture, due to both lack of immediate time ana the inherent characteristics of the cell which prohibited high tempera- ture operation. Some observations of temperature effect on 11 the ch1orohyrin forming reaction are on recorä. in the literature (14).

The rate of stirring was maintained constant at all times during the investigation. As complete a distribution of ethy1ene in the anolyte as possible was had. by stirring at a maximum speed, the optimum conditions of distribution being approached (15).

The ethylene ch].orohydrin used, in this research was the anhydrous '98% Purity blend manufaotured. b the Union

Carbide and. Corporation, This material analyzed. approximately 98.6q0 ethylene chlorohydrin by the hydrolysis method and by an acetylation method. The ethylene used was of the grade accepted by the American Medical Association for use as an anesthetic, produced by the Ohio Chemical and. Manufacturing Company. All chemicals used. in analysis and, elsewhere in the experiment were of standard C. P. analytical grades.

(14) JIaddan, R., loe. cit.

(15) Bozza & Mamoli, loe. cit.; Ellis, Carleton, loe. cit. ANALYTICAL PROCEDURE

The analytical procedure involved in the periodic

examination of the cell contents consisted of three parts, namely, analysis for total acidity, hydrochloric acid con- tent, and. the sum of hydrochloric acid and ethylene chlore- hydrin. A one cc sample was used in each part.

Total acidity was determined by against standard sodium carbonate solution using methyl orange as indicator.

Hydrochloric acid content was determined by titration of the neutral solution from the determination of total acidity with standard silver nitrate solution using a 5% solution of potassium chromate as indicator (the Mohr titration).

The analysis for the total of the ethylene chlore- hydrin and hydrochloric acid. was made by first neutralizing the hydrochloric acid in the sample with 3 normal sodium , then adding 3 oc of 3 normal and heating in a steam bath for 15 minutes. This gave quantitative and reproducible hydrolysis of the ethylene chlorohydrin. 'ollowing this treatment the solution was allowed to cool, and was neutralized to the phenolphthalein end point with normal . The total chlorides were determined by the aforementioned Mohr titration. 13

The hydro1ysis treatment, as described, had little effect on the higher chlorides formed during electrolysis.

With 1mori. samples of ethylene chloride of higher con- centration than expected in the cell, treatment with 10 cc of 5 normal sodium hydroxide and heating in a steam bath for one hour gave a hydrolysis of only 3%. DISCUSSION

The variables whose effects were observed, in this re- search were hydrochloric acid. concentration, carrent

density, and. concentration o± ethylene chloroh1yd.rin.

The plates showing the course of the reactions in the cell show in all cases that three distinct types of re- action occur as the electrolysis proceeds. These are shown on the curves oy the three periods of definite slope of the chlorohydrin line.

During the first period of electrolysis a theoretical yield of ethylene chiorohydrin was obtained., assuming the reaction at the anode to be

cf- 2(e) + 012

012 + HOH 1101 + H001

11001 + 0H2:0H2 : 1100211401

This period. lasted in all cases only five ampere hours and the length of the period appears to be independent of the concentration of acid and the carrent density.

During the second. period the ohlorohydrin line assumes another slope. Some ethylene d.ichloride is formed during this period., but the amount of ethylene used does not fall off from the amount necessary for theoretical chlorohyd.rin formation. This fact shows that the amount of dichioride formation is negligible. The amount of hydrochloric acid 15 d.ecomposed. does not quite o11ow the theoretical line, suggesting a certain amount of decomposition of water.

Confirming this is the fact that at odd. times the quantit7 of hydrogen being evolved at the cathode was measured. and. found to oonorm quite close1y to 100% cathode current

efficienci. j assuming the oxidation of ethylerie at the anode b,y the oxygen evolved. from the electro1sis of water, the theoretical amount of ethylene can be near1 accounted for, the rest probab1y being used. in the forma- tion o± dichlorid.es, higher chlorid.ee, and. , which are just d.etectable. This oxid.ation may be explained. b the add.ition of nascent oxygen at the electrod.e to the unsaturated ethylene molecule, giving ethylene oxide which hyd.rolyzes to glycol, or according to the peroxide theori o± anod.io oxidation, the hvdrogen peroxid.e liberated. at the anode reacts with the ethylene molecule giving glycol directly.

The third period begins when the concentration of chlorohydrin reaches the point where, in conjunction with the concentration of hydrochloric acid., it is conducive to

the formation of ethylene chlorides.

+ CH2:C2 - 0102H4C1

During 'this period measurable quantities of the chlorides were formed..

During the third period some acid was formed., aug- j

gesting the further electrolytic oxidation of glycol,

ethylene, and ohiorohydrin to aliphatie , substituted and. hydroxy acids. Whether the oxidation con- tinues to yield 002, 00, ROH in the case of the aliphatic

acids, or 012, HOi, ROH in the case of ohioroacetie acids

(16) is not certain. The exact nature of electrolytic

oxidation has not yet been stated in a manner acceptable

and applicable in all cases, and the nature of the solvent, added ions, etc., has a great effect on the evolved prod-

ucts (17).

The effect of varying the hydrochloric acid. concen-

tration is shom in comparison of Plates i and II. In

Plate I the acid. concentration i8 approximately half that

shown in Plate II. 'These curves show that at a hydrochio-

Tic acid concentration of 0.722 normal, the maximum con-

centration of chiorohydrin attainable before the dichioride

forming reaction sets in is 8%. At an acid concentration

of 1.485 normal, the maximum concentration of chiorobydrin

attainable before the d.ichloride forming reaction sets in

is o%. By examination of the slopes of the second period.

of the two ohlorobydrin curves, the current efficiency of

(16) Roake, W. E., "Electrolytic Oxidation," a summary of Reading & Conference, Oregon State College, 1941.

(17) Brookman, 0. J., Eleotro-organic Chemistry, John Wiley & Sons, Inc., New York, Chapman & Hall, Ltd., London, 1926. the ch1oroh'drin forming reaction is 61.5% in the lower acid, concentration and 7$ in the higher acid concentra- tion. These facts seem to indicate that the hdrooh1oric acid concentration is a strong factor in determining the maximum oonoentration of chlorohyd.rin attainable before the unwanted. side reactions set in. However, the fact that the curves show a theoretical amount of chlorohyd.rin forned. in the first period in both cases to the conclusion that the acid, concentration alone is not the controlling factor, but that it works in conjunction with the concentration of the ethylene chlorohydrin.

The effect of variations in current density is sho'wu in the comparison of Plates I and. III. The only noticeable difference is in the slope of the ohlorohydrin lines during the second. period.. At a current density of 0.378 amperes per square inch the current efficiency of the ohlorohydrin forming reaction is 61.5%. In Plate III, at a current density of 0.189 amperes per square inch, the current efficiency for that reaction was 74%. This indicates that the optimum conditions are approached. by increasing the anode area per volume of cell. The effect of variations in the concentration of ethylene chiorohydrin is tied up with the concentration of hydrochloric acid. These effects are shown by the presence of the three definite slopes o± the chiorohydrin lines in

Plates I, II, and III. Cs' ---- * 24 LI - I. C V4> 20

Is r- L&I -I fTI p (A 4m -I r I EEIIIE r- , - : .__ ..__ S=::: 0zVI LLJQ 'z - - . HCI E 8 ' !EiiIIIIIIIÏ)2rXY II tAcic -)__ 4 2 uni _ÏIIIIIIIIIIIIIIÏw w 50 40 50 :. i. AMPERE HOURS PLATE I L ------///- - __ L _ //

I. -J -J wo i__t ---- 'i Q r- -I 'na -- . I------.2 - l'i z / .4 Lii X -J '-C (n D _ IuIIIuI m

LiJO I 1 __ __ t D ___ __ I L I--- L:,cr ) (OCLI14CI

i_____;r a, _ I_'-P---ï----IIIIIIIII lo ZO 50 40 50 TO 80 AMPERE HOURS

PLATE lt (3 I ______ri

-I -J w -I C., f,'

(I,

I, (n zI- X-I w .i( I-

I r' _____ u a z i. - f,,

I _ .4 ______u

O IO *0 30 40 50 70 60 90 AMPERE HOURS PLATEIff ot\J CONCLUSI ONS

The following conclusions apply within the ranges investigated:

1. It is possible to prepare ethylene chloroh.ydrin by the introduction of ethylene gas into an electrolytic cell in whioh an aqueous solution of hydrochloric acid, is being electrolyzed., the ethylene combining with the hypo- chiorous acid formed, by the reaction of evolved. chlorine with water.

2. In all electrolyses observed, the formation of ethylene ehlorohydrin at a theoretical rate continued. until a concentration of approximately 0.15 normal was reached.

3. Higher anode current densities favor higher rates

of electrolytic oxidation of ethylene.

4. Evidence obtained in this investigation indicates

that as a factor in determining the maximum concentration

of ethylene chiorohydrin attainable before the formation of

ethylene chloride sets in, neither the concentration of the

chlorohydrin or the concentration of hydrochloric acid is

independent of the other. Together, they set the maximum

li rai t.

BIBLIOGRA.PHY

Bozza & M.ino1i. Giorn, China. lucI. e pp1icata, 12, 283- 92, (1930); 0. A., 24, 5021, (1930). Brockniari, C. J. Electro-organic chemistry. John Wiley & Sons, Inc., New York, Chapman & Hall, Ltd.., London, 1926. Carius, Ann. 126, 197, (1863). 1lis, Carleton. The cheinistr of derivatives. The Chemical Catalog Co., Inc., New York, (1934).

Essex & Ward.. U. S. Pat. 1,594,608; 0. A., 20, 3170, (1926). Prahm, E. D. 2. The preparation of glycol ch1orohydrin. Reo. Tra.v. Chini., 50, 261-7, (1931); 0. A., 25, 2690, (1931).

Gomberg, M. Eth1ene chlorohycirin & ø,ødichloroethyl sulfide. J. A. 0. 5., 41, 1414, (1919); 0. A., 13, 2369, (1919). Had.d.an, R. Brit. Pat. 140,831; J. Soc. Chern. md., 39, 426, (1920).

Irvine & Haworth. U. S. Pat. 1,496,675; 0. A., 16, 2345, (1924).

icE1roy K. P. U. S. Pat. 1,253,617; 0. A., 12, 703, (19l3. forris, C. A., 2740, (1919). Pogorzelski, Ohem. Zentr., I, 79'?, (1905). Roake, W. E. Electrolytic oxidation. A sumrnar of read- ing and conference, Oregon State College, 1941. Shilov, E. A. J. Cliem. md. (Moscow), 5, 1273-6, (1928); C. A., 23, 2937, (1929). Wurtz, Ann. 110, 125, (1659). APPEIDIX 23

TABLES

PLTB I

Plate I is the combination of two series of data of the same system.

Series A

Current Density -- 0.378 amp./sq. in. Constant HOi -- 0.768 normal

.m.pore Hours Equivalents otal Acid Liters Oblorohdrin Minus HOi Ethylene Porined. Used

o o o o 2.5 0.058 0 1.0 5.0 0.098 0 ¿.1 7.5 0.125 0 3.2 10.0 0.148 0 4.2 12.5 0.189 0 5.2 15.0 0.217 0 6.3 17.5 0.248 0 7.3 20.0 0.279 0 8.4 22.5 0.309 0 9.4 25.0 0.339 0 10.5

Series B

Current Density -- 0.376 amp./sq. in. Constant HOi -- 0.722 normal

.àmpere Hours Equivalents . Total Acid. liters Ohiorohydrin Minus HOi Ethylene Pormed. Use

o 0.470 0 0 2.5 0.495 0 1.1 5.0 0.529 0 2.1 7.5 0.534 0.003 3.1 10.0 0.558 0.012 4.0 12.5 0.550 4.9 15.0 0.566 0.012 5.7 20.0 0.600 0.025 7.0 25.0 0.626 0.028 8,2 PLATE II

Current Density -- 0.378 arnp./sq.. in. Constant HOi -- 1.485 normai impere Hou.r$ Eq.uivaient$ Total Acid. Liters Ch1orohd.rin Linu.s ECl Ethylene Pormed. Used.

o o.oi o o 2.5 0.038 0 1.1 5.0 0.107 0 2.1 7.5 0.122 0 3.2 10.0 0.163 0 4.2 0.222 0 5.3 :is.o 0.244 0 6.3 17.5 0.266 0 7.1 20.0 0.299 0 7.7 22.5 0.313 0 8.1 25.0 0.335 0 8.7 27.5 0.341 0 9.3 30.0 0.365 0 9.5 32.5 0.339 0 35.0 0.402 0.022 10.4 37.5 0.404 0.022 10.6 40.0 0.415 0.034 11.1 25 PLATE III

Plate III is the combination of two series of d.ata of the same system.

Series A Current Density -- 0.189 amp./sq. in. Constant HC1 -- 0.782 normal Ampere Hours Equivalents Total Acid. Liters Chiorohydrin Minus HC1 Ethylene Formed. Used.

o o o o 2.5 0.043 0 0.8 5.0 0.086 0 2.0 7.5 0.117 0 3.2 10.0 0.156 0 4.5 12.5 0.190 0 5.5 lo.0 0.22 O 17.5 0.254 0 7.3 20.0 0.296 0 8.5 22.5 0.321 0 9.5 25.0 0.359 0 10.5 7.5 0.384 0 11.6

Series B Current Density -- 0.189 amp./sq. in. Constant HOi -- 0.710 normal Ampere Hours Equivalents Total Acid. Liters Chiorohydrin Minus HOi Ethylene Formed. Used.

o 0.469 0 0 2.4 0.524 0 1.5 4.9 0.543 0 ***** 2.5 6.7 O 3.4 11.7 0.582 0 5.2 17.9 0.579 0.003 21.0 ***** ***** 7.1 23.2 0.617 0.010 28.2 0.627 0.024 9.1 36.9 0.670 0.030 11.3