Document YjbaLrYjyKwOXRgL3yXo1v8py

RESEARCH DEPARTMENT - PHOSPHATE DIVISION SHCRT FORM REPCRT Report Ho.i 2790 Work Started: Work Completed: Date Reported: October 15, 1951 Hay 15, 1952 July 3, 1952 Job No.: File No.: 171-1028 141-27-3 Investigators: A. H. Ellenburg H. B. Richards, Jr. J. E. Feltham Distribution: Research File R. L. Jenkins - St. Louis H. V. Moss C. A. Hochwalt - St. Louis N. N. T. Samaras - Dayton Edgar E. Hardy H. F. Weaver - St. Louis A. H. Ellenburg W. T. Durrett R. P. Loewen H. 0. Tittel cony For*-C. Barbre - Monsanto, 111. T. W. Daltqn - Monsanto, 111 Jack C' orn Extra TITLE: Increased Production of Aroclor by Here Rapid Rate of Chlorination INTRODUCTION: In view of the desired eight-million pound per year increase in distilled Aroclor produc tion, plant experiments were made Increasing the rate of chlorination of biphenyl to crude liquid Aroclors to determine if the Aroclors eo produced would meet the present specifica tions. SUMMARYs Several experimental chlorinations in chlorinetors 5 and 6, which have been modified for more rapid chlorination rates, were carried out on batches of 1142 and 1154 at increased chlorination rates. These fast chlorinations (up to 770 pounds chlorine per hour) were compared to normal operations (550 pounds chlorine feed) iq these modified chlorinators and to normal operations (400 pounds chlorine feed) in chlorinators 3 and 4, which have not been modified for rapid chlorination. In ill cases the Aroclors produced at the increased rates were within specifications. CONCLUSIONS: 1. Production of crude Aroclors with existing equipment has been increased about 30$ in modified chlorinators 5 and 6. 2. An additional Increase of up to 40$, over this 30% increase, is within possibility by closer control of the chlorine feed rate on Aroclor 1142. 3. The additional increase in feed rate on Aroclor 11)4 is only 15$, and on Aroclor 1160 it would be less. The inability to continue the Increase in chlorine pressure accounts for the reduced improvement. 4. Better dispersion of chlorine is not needed in the chlorination at high feed rates to obtain specification grade Aroclor. This report and the information contained herein is the property of vON-fANur. CH PiTt'C ' ; 0143051 HARTOLDMON0004802 Report No. 2790 -2- RECOMMENDATIONSi It is recommended that the four unmodified cbiorinatcrs be equipped with individual cyclone entrainment separators so that they nay be operated at mare rapid rates of chlorination, if the proposed increase in Arcelor production is to be carried out. 01*3052 HARTOLDMON0004803 Report 2790 -3- EXPERIMENTAL DATAt Notebook References - 74867-8, 74870-1, 74873, 74875-6, 74881, 74894-5, 77351-7, 77364-71, 80514-16, 82604-6. CHLORINATION DATAi TABLE I REGULAR AROCLOR 1142 CHLORINATIONS NO. 5 CHLORINATOR AT INCREASED RATE, NOS. 3 AND 4 CHLORINATORS AT NCRUAL RATE Run No. Date Chlorinator No. Avg. Rate, Lbs. Cla per Hr. Chlar. Time, Hrs. Equivalent* Chlar. Time, Hrs. Charge to Chlor., Lbs. Product Pounds Chlor. Time Before Circulating, Hrs. 455 4/21/51 4 307 10/24/51 5 389 1/11/52 3 377** 5/14/52 5 383** 5/15/52 5 437 574 378 537 521 13.0 9.9 13-5 9-5 9.8 -- -- 15.0 10.6 10.8 4000 4000 3600 3600 ' 3600 7400 7100 5900 7100 7100 4-3 3.8 -- 3.5 4.0 * The calculated time that would have been required for the chlorination of a full charge of 4000 lbs. of biphenyl. These two runs are 1154 chlorinations on which the data are given through the 1142 stage as a basis of comparison far the experimental chlorinations in this chlorinator. See Table II. / 0143053 HARTOLDMON0004804 Report No. 2790 -4- TABLE II EXPERIMENTAL 1142 CHLCEINATIOHS IN NO. 5 CHLCRINATCR Run No. Date Avg. Rate, Lbs. Cl* Per Hr. Chlcr. Time, Hrs. Equivalent Chlor. Time, Hrs. Charge to Chlcr., Lbs. 278 10/16/51 756 7.5 -- 4000 303 10/25/51 515 11.0 -- 4000 341 11/20/51 568 10.0 -- 4000 293* 3/25/52 639 8.0 8.9 3600 381* 5/15/52 786 6.5 7.2 3600 Product, Lbs. -- 6500 5900 -- -- Chlor. Time Before Circulating, Hrs. -- . -------- -- 1.42 1.5 * 1154 Chlorinations, data taken only through 1142 stage. NOTES Runs 278, 303, and 341 were carried out by the plant and data given to Research. Runs 293 and 381 were carried out in the plant by research personnel. TABIE III REGULAR 1154 CHLORINATIONS AT INCREASED RATES Run No. 799 819 977 Date Chlor. No. Avg. Rate, Lbs. Cla Per Hr. Chlor. Time, Hrs. 10/25/51 10/30/51 12/20/51 5 5 6 671 505 545 12.2 16.2 15.0 Charge to Chlor., Lbs. 3600 3600 3600 Product, Lbs. 7400 -- -- Chlor. Time Before Circulating, Hrs. 3.2 3.8 3.2 0143054 HARTOLDMON0004805 Report Ho. 2790 -5- TABLE XV EXPERIMENTAL 1154 CHLOSINATIOHS Run Ho. Bate Chlor. No. Avg. Rate, Lbs. Cl, Per Hr. Chlor. Tine, Hrs. Equivalent Chlor. line, Hrs. , Charge to Chlor., Lbs. Product, Lbs. Chlor. Tine Before Circulating, Hrs. 292 66 86 10/22/51 1/15/52 1/18/52 5 6 6 618 671 693 14.7 12.2 11.8 13.3 -- -- 4000 3600 3600 7700 7330 7440 -------1.0 1.0 TABLE V AROCLCR CHURIKATION HATES Aroclor 1142 1154 Operating Conditions 1. Regular plant operation 2<5 Increased plant operation .* Experimental operation r*- Regular plant operation < 2. 3* Increased plant operation Experimental operation Avg. Rate, Lbs. Cl, Per Hr. 410 545 770 415 575 660 % Increase Over Condition 1' 2 -- -- 33 -- a88 -- -- 39 -- 59 15 [ \ 0143055 HARTOLDMON0004806 Report No. 2790 Data on Laboratory Distilled Aroclora from Rapid Chlorinationss TABLE VI AROCLCB 1242 ANALYSES Property % Recovery on Distillation Color, AFHA Condition Sp. Qr. at 25*C. Acidity Inorg. Cl., ppm. Viscosity, S.U.S. at 100*F. D. X. at 100*C. _q Resistivity, ohm-cm X 10 at 100'C. Ref. Index at 25 *C. Pour Point,*C. Rater, ppm. Dist. Range, *C. Corrected 10Jf 50* 90* Corrosion Test 278 Him Number 303 341 293 381 . 96.7 20+ Clear 1.384 0.001 0.05 85.4 4.68 98.4 -- Clear 1.380 -- -- -- 4.80 95.0 25 Clear 1.378 -- -- -- 4.82 98.8 -- Clear 1.388 -- -- -- 4.86 98.4 35 Clear 1.390 0.001 0.05 89.8 4.89 11,000 5,700 1,400 4,500 1.6263 1.6245 1.6243 -- -18 86 -- -- -- -- -- -- 6,400 1.6253 -18 90 317 331 350 337 366 352 passes -- 329 337 353 -- 332 339 357 ---- 332 339 354 passes Control Specification 100 max. Clear 1.378-1.388 0.014 max. 0.1 max. 83 i 5 4*7-n4.9 5OO min. 1.6245-1.6265 -14 max. 35 max. 0143056 HARTOLDMON0004807 Hepart No. 2790 TABI VII AROCLCR 1254 ANALYSES Property Run Number 292 6 86 ? Recovery in Distillation 97.6 Color, AFHA Condition 45 Clear Sp. Gr. at 65*C. Acidity, '52-iBOH Inorg. Cl., ppm. 1.498 0.001 0.05 Viscosity, S.U.S. at 98.9*C. D. K. at 100*C. Resistivity, ohm-cm X 10"^ at 100 *C. 45-2 4-23 12,000 Refractive Index at 25*C. Pour Point, *C. 1.6379 8 Water, ppm. 33 Evap. Loss at 100*C., ? 0.024 Distillation Range *C., observed 10? 354 50? 360 90? 370 Corrosion Test P&8SS8 96.3* 95 63 Clear 35 Clear -- -- 1.498 0.001 -- 0.05 -- 45-4 -- 4.15 3,400 7,300 1.6380 1.6387 -- 8 -- 35 -- 0.032 355 360 371 --'-- 354 359 368 pas968 ^ No lime in distillation -7- Control Specifications ___ ___ 100 max. Clear 1.495-1.505 0.01 max. 0.10 max. 44-47 4.15-4.35 >500 1.6370-1.6390 8-12 35 max. 0.4 max. 350-355 355-362 362-379 01*3057 HARTOLDMON0004808 Report No. 2790 -8- Qraphs* Data for the curves, Graphs I, IX, and III are tabulated as followsi GRAPH I SPECIFIC GRAVITY OF CHLCRINATEJ) BIPHENYL VS. % CHLORINE at 25*C. Sp. Or. % Cl. 1.182 1.267 1.383 1.452 1.543 1.623 1.807 1.033 ** 21 32 42 48 54 60 68 0 at 65C. Sp. Gr. % Cl. 1.155 1.243 1.348 1.414 1.505 1.587* 1.773* 1.000** 21 32 42 48 54 60 68 0 * Estimated from 25 *C. curve Extrapolated values for biphenyl 0143056 HARTOLDMON0004809 Heport No. 2790 GRAPH IX SPECIFIC GRAVITY VS. TOTAL CHLORINE FEKD FCE 3600 LB. CHARGE OF BIPHENYL It can be shown that for chlorination of biphenyl - -9' 0.972 X + 2 I where X total weight of chlorine feed, pounds T weight of biphenyl charged, pounds Z decimal fraction of chlorine in the product (i.e. for Aroclor 1254, Z - 0.54) Using this equation, and reading the % chlorine vs. specific gravity curve. Graph I, the following data are obtained for a 3600 lb. charge of biphenyl! % Chlorine 10 20 30 40 50 60 70 Sp. Gr. at 65'C. 1.067 1.144 1.229 1.325 1.445 1.600 1.825 Total Weight of Chlorine Feed. Its. 797 1,788 3,050 4,710 7,010 10,360 15,740 HARTOLDMONOOQ4810 Report Ho. 2790 GRAPH III RATE OF CHLORINATION VS. TUB CHLCRINATCR NO. 6 AROCLQR 1154 REGULAR RON 977 -10- Time Elapsed, Hr. Specific Gravity at 65*C. 0 1.58 2.58 3.58 4-58 5-58 7.08 8.08 9.08 10.08 11.08 12.08 13.08 14-33 15.00 Average Rate 1.000 1.068 1.092 1.129 1.172 1.202 1.272 1.312 1.333 1.368 1.416 1.430 1.475 1-485 1.506 Cumulative Wt. of Cla Feed, Lbs. Increase in Cl,, Lbs. ____ 800 1,100 1,600 2,200 2,650 3,750 4,430 4,800 5,450 6,360 6,650 7,630 7,840 8,300 T.- -- - 800 300 500 600 450 1,100 680 370 650 910 290 980 210 460 Avg. Rate per Interval, Lbs. Cl2 Feed Per Hr. Cl3 Back Pressure Psig. ,,__ 506 300 500 600 450 734 680 370 650 910 290 980 168 687 553 H 15 15 20 20 20 25 25 25 25 25 25 28 28 28 01*3060 HARTOLDMONOOQ4811 Report No. 2790 -11- AROCLCR 1154 EXPERIMENTAL RUN 66 Time Elapsed, Hrs. Specific Gravity at 65*C. 0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 12.17 Average Rate 1.000 1.060 1.078 1.120 1.160 1.209 1.246 1.285 1.316 1.361 1.403 1.445 1.490 1.498 Cumulative Wt. of Cla Feed, Lbs. 700 930 1,470 2,030 2,760 3,340 3,980 4,500 5,300 6,120 6,980 7,950 8,150 Increase in Cl,, Lbs. 700 230 540 560 730 580 640 520 800 820 860 570 200 Avg. Rate Per Interval, Lbs. Cl Feed Per Hr. _____ 466 460 540 560 730 . 580 640 520 800 820 860 970 1,177 670 Cla Back Pressure, Psig. 16 18 20 20 24 24 28 28 32 32 32 35 35 35 01*3061 HARTOLDMONOOQ4812 Report Ho. 2790 -12- AROCLCR 1154 EXPERIMENTAL RUN 86 Time Elapsed, Hrs. Specific Gravity at 65*C. 0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9-0 10.0 11.0 11.75 Average Rate 1.000 1.070 1.087 1.130 1.168 1.215 1.255 1.296 1.333 1.378 1.420 1.467 1.500 Cumulative Wt. of Clg Feed, Lbs. Increase in Cl*, Lbs. Avg, Rate Per Interval Lbs. Cla Feed Per Hr. 830 1,030 1,600 2,150 2,850 3,490 4,150 4,810 5,630 6,470 7,650 8,180 830 200 570 550 700 640 660 660 820 8(0 1,180 530 - -r --. 553 400 570 550 700 640 660 660 820 840 1,180 707 696 Cl* Back Pressure, Psig. 16 18 18 20 22 24 26 28 30 32 34 34 34 0143062 HARTOLDMONOOQ4813 SPEC IFIC GRAVITY PER CENT CHLORINE 01A 3063 HARTOLDMONOOQ4814 % CHLORINE TOTAL W EIGHT OF CHLORINE FEED , POUNDS SPECIFIC GRAVITY AT 65*C. I'*306<, HARTOLDMONOOQ4815 0143065 900 oownnv 700 600 500 400 300 200 100 0 TIME IN HOURS HARTOLDMONOOQ4816 Report No. 2790 -13- DISCPSSIONi Chlorinators 5 and 6 have been modified for rapid chlorination by installation of small individual cyclone entrainment separators with return lines to the chlorinators. Normal plant operation in these two chlorinators is faster than in the unmodified chlorinators, but observation of the plant operations indicated that the time of chlorination might be even further reduced by better control of chlorination rates throughout the chlorination. Graph III of this report shows the rate curve for a normal plant chlorination, Run 977, which is typical of the rate curve for usual plant operation. The rate of chlorination starts low, builds up in excess of 700 to 8CO pounds per hour toward the middle stage, sometimes greater than 1000, and then decreases toward the end. This behavior results from inadequate control of the chlorine pressure being supplied to the chlorinator. It seemed apparent that by controlling the chlorination more closely to give more uniform rates, considerable time might be saved during a chlorination. Two experimental plant runs were made during which the chlorine was admitted at a faster rate throughout the run. Chlorinator 6 was chosen for these tests because it is one of two chlorinators equipped with small individual entrainment separators as well as the large cyclone separators. Chlorinators 1, 2, 3> and 4 are equipped with the large separa tors only. The first test run. No. 66, required twelve tours and ten minutes to complete the ohlorination. The chlorine was admitted at an initial back pressure of sixteen pounds and after gradual increases for the first several hours, the pressure was increased four pounds every two hours until a final pressure of thirty-five pounds was reached. This pressure was maintained at thirty-five pounds for one hour and ten minutes with no appar ent difficulty. The second test run. No. 86, required eleven hours and forty-five minutes. This run was started at an initial chlorine pressure of sixteen pounds; however, during this test, the pressure was increased two pounds every hour until a maximum pressure of thirty-four pounds was attained. At the beginning of Run No. 66, the chlorine tank car was practically full, and during the run the pressure of the car decreased from 80 to 76 p.s.i.g. The only unusual observation was that the chlorine vapor linp coming out of the vaporiser turned cool when a back pressure of thirty-five pounds was reached. At the beginning of Run No. 86, the chlorine tank car was about half full, and while the pressure of the car remained constant throughout the run, the pressure was only 63 p.s.i.g. The maximum back pressure of thirty-four pounds could not be increased at the conclusion of the run. Circulation of the material in the chlorinator was started only one hour after chlorina tion was started. The usual plant procedure is to wait three or four hours; however, because chlorine was going in at a faster rate, circulation was starter earlier. The temperature of the chlorinator was easily maintained within the required operating temperatures of 105*C. to 150*C. HARTOLDMONOOQ4817 Report No. 2790 -14- At the conclusion of each run, thB trappings, or material collected by the cyclone separa tor, irere drained. Material from chlorinators 3, 4, 5 and 6 totalled approximately onehalf of a 55-gallon drum. This was considered normal by the operator. Graph III also shows the rate curves for these two experimental chlorinations. There appears to be little difference in raising the pressure four p.s.i.g. every two hours, and in raising it two p.s.i.g. every hour. Both of these runs started at about 500 pounds of chlorine per hour, gradually increasing toward the middle of the run, and then entered a somewhat greater upward trend toward the end of the run. These curves of course show only the general trends in the rates. There is still considerable variation, but not as wide as in the regular runs. Tjie reduced time of chlorination is adequate proof of the effectiveness of the method. Table III and Table IV show the detailed data for the 1154 chlorinations, both regular and experimental operation. Table V shows the averages of the chlorination rates under the various conditions and gives the percentage increases in each case. An increase of nearly 60% was realized in the experimental Aroclor 1154 chlorinations over the regular plant operations. An increase of nearly 40* has already been shown in plant operations on No. 6 chlorinator over operations on the unmodified chlorinators. Table VII gives the analyses of the Aroclors from tjie experimental operations, all of which are within speci fications . Several experimental runs were carried out on Aroclor 1142 in chlorinator 5* Table I gives typical data for regular 1142 chlorinations as compared to the experimental chlor ination data given in Table II. Comparison of data in' these two tables shows that an increase of about 33% in plant production has been brought about in chlorinator 5, arri that a further increase of 41^ over this rate is possible, or a total overall increase of 83%. This comparison is tabulated in Table V. It should be pointed out, however, that this increase in production was accomplished on only one chlorinator, and that a similar increase on all the chlorinators would be largely dependent upon an adequate supply of chlorine to maintain these increased feed rates. Table VI gives the analyses of the Aroclor 1242 samples from the experimental 1142 chlor inations. All of these samples were within specifications except that from Run 278 which had an unusually wide distillation range. Runs 303 and 341 were made at lower rates of chlorination and gave satisfactory Aroclors. It was then thought that finer dispersion of the chlorine by a glass cloth might make possible more rapid rates without producing off-grade Aroclor. Run 293 was made with such a cloth over the chlorine distirbutor and specification grade Aroclor resulted; however, the rate of chlorination was not as high as in Run 278. Subsequent examination of the glass cloth revealed that it had farmed a matte-like material and had so constructed the flow of chlorine that the resulting pres sure had ripped the cloth at the seam. For this reason, it was considered entirely un satisfactory for this application. Furthermore, the data for Run 381 show that speci fication grade Aroclor 1242 can be produced at even a faster rate than employed in Run 278, and without further modification of the equipment. This rate of 786 pounds of chlo rine per hour is the highest overall average rate yet attained in an experimental plant chlorination. It must then be concluded that the glass cloth is of no value in the chlo rinator, and that the wide distillation range obtained in Run 278 was not due to the rapid chlorination rate, but was probably due to higher chlorinated trappings being charged to the chlorinator. 0lOOb7 HARTOLDMONOOQ4818 Eepart No. 279& -15- From the foregoing facts it may be stated that an increase in production of about 30% has already been accomplished in the plant on No. 5 and No. 6 chlorinators, and that an addi tional increase of up to lfi% over this 30% is within possibility depending largely upon the chlorine supply available. Although no specific test was run on Aroclor 1260, regular production during periods of fast chlorination rates was satisfactory. Theoretically, there is also less chance of varying the isomer distribution of the Aroclor 1160 then of the 1142. Therefore, any change in properties is unlikely in view of the successful Aroclor 1242 and 1254 tests. In consideration of the maintenance of equipment, the erosion of the distributor plate will be greater at the high chlorine feed rates. Observations have indicated that the plates may last only about a third as long as at the slow feed rates of 4OO-5OO pounds per hour. Increasing the number of holes in the distributor plate would help in lessening the erosion. The replacement of catalyst may also be a more frequent practice. At the higher feed rates, the chances of localized high temperatures in the reaction zone are good and will allow more iron chloride to be formed, thus using up the iron turnings at a faster rate. be 7-22-52 0143068 HARTOLDMONOOQ4819