Document Vjqz26Jjvvn2gw24zeN8nKmYo

VINYL CHLORIDE PQSBTBfifSOURCES OF POLYMERIZATION INHIBITORS IN NO. 1 SYSTEM COPIES TO Dr. J. N. Wickert Mr. D. B. Benedict Mr. R. D. Glenn Mr. K. H. Rowland Mr. C. R. Ferris Mr. I. F. Ferrer Mr. I. R. MacMillan Mr. T. A. Wilker Mr. C. P. Bennett Mr. v/. E. Fersbacker Mr. D. L. Snyder Dr. J. P. Creagh Mr. W. C. Heidenreich AUTHORS DAT! S. 7. Clark J. V. Schilling B* C. Wood V, A. Yarborough September 13,1945 REFERENCE D-S01-10; D-773-35 FILE 34 SUMMARY Two possible sources of the inhibitor which is interfer ing with the polymerization of vinyl chloride from Vinyl Chloride Unit No. 1 were investigated. A sample of the kettle residue from the vinyl chloride refining still at Building 154 was distilled through a column of 46 theoretical plates. The fractions were analyzed on the mass spectrometer. The major components found in the sample were ethylene dichloride, propylene dichloride, vinyl chloride, acet aldehyde, and trichlorethane. Small amounts of vinyl bromide, 1,1-dichlorethane, dichlorethene, allyl chloride, propyl chloride, acetone, methyl chloride, dichlormethane, chloroform, and water were also present. Seventy per cent of the charge was recovered as good ethylene dichloride which did not affect vinyl acetate polymerization. Inhibitory material present appeared to be con centrated in fractions 1, 2, and 3. These fractions boiling between 13 and 25C. were the only ones to reduce appreciably th polymerization rate of vinyl acetate. The composite fraction contained approximately 76 per cent vinyl chloride, 15 per cent acetaldehyde, and small amounts of propyl chloride, dichlorethane, dichlorethene, and vinyl bromide. A sample of low boiling fore-fraction from the refining of ethylene dichloride at Building 42 was distilled in the labora tory using a column of 46 theoretical plates. The various fractions were analyzed on the mass spectrometer. The material was found to contain large amounts of ethylene dichloride, ethyl chloride, chloroform, and dichlorethene. Acetaldehyde, oarbon tetrachloride, dichlorethene, dichlormethane, acetone, allyl chloride, propyl chlciride, methyl chloride, and formaldehyde were present in small amounts. UCC 032498 2 No unusual compound that would reduce the polymerization rate of vinyl chloride was found in either the fore-fraction or kettle residue samples. INTRODUCTION A survey was made of possible sources of the Inhibitor which has appeared in the vinyl chloride from Vinyl Chloride Unit No. 1 during the past several months. The process was traced with the assistance*of all technical men concerned from ethylene through ethylene dichloride to vinyl chloride and its distillation in the No. 2610 still at Building 154. Two samples were selected for careful examination. The first of these was a portion of the residue which was obtained from No. 2610 still and which consisted largely of ethylene dichloride. The second sample was obtained from the fore*fraction isolated in the refining of ethylene dichloride, the raw material for the production of vinyl chloride. This fore-fraction is discharged to the sewer. The residue from No. 2610 still is also discharged to the sewer at present, but there is considerable Interest in reworking this material to recover ethylene dlchloride at Building 42. DISCUSSI The procedure involved in handling the samples was the same in eich case. Approximately 1,500 grams of sample was charged to a 2-liter flask equipped with a Glas-col heating mantle. Maintaining a- 5:1 reflux ratio, the material was distilled through a vacuum-jacketed column of 46 theoretical plates. The column was packed with 1/16-inch nichrome helices. A brine-cooled condenser was used and the low boiling fractions were collected in a dry ice-acetone cold trap. Fractions collected at appropriate intervals were examined on the Consolidated mass spectrometer. A. Kettle Residue from Still No. 2610 at Building 154 Vinyl chloride produced by the reaction of ethylene dichloride and aqueous sodium hydroxide at Vinyl Chloride Unit No. 1 is refined at Building 154- A sample of the kettle residue from refining still No. 2610 was fractionated in the laboratory through a column of 46 theoretical plates. About 4 per cent of the charge boiled below 25C. and contained mostly vinyl chloride and acet aldehyde. The major portion (62 per cent) of the charge boiled between and S3.5 centigrade. A specific gravity of 1.25 at 20/15.6C. indicated this material to be fairly cure ethylene dichloride. Details of the distillation are shown in Table I. The residue, comprising 22 per cent of the charge, had a boiling range of 96 to 127 centigrade. Results of a standard distillation of a 100-cc. sample of the residue are listed in Table II. Samples of the various fractions were examined on the Consolidated mass spectrometer. In addition to ethylene -dlchloride, vinyl chloride, and acetaldehyde, the sample also contained methyl chloride, water, dichlorethene, 1,l-dichlorethane, dichiornethane, and chloroform. UCC 032499 - 3- Snail amounts of vinyl bromide, allyl chloride, propyl chloride, and acetone were also found, and the standard distillation revealed the presence of propylene dichloride and trichlorethane in the residue. Results of the spectrometer analyses are shown in Table III. A summary of the quantitative data on the original sample based on the distillation and spectrometer analysis is given in Table IV. The inhibitory effect of the various fractions was determined by means of a modified vinyl acetate activity test. One cc. of contaminant was added to 22 cc. of one-period vinyl acetate containing 0.40 gram dibenzoyl peroxide. The number of 15-second heating periods required to start polymerization is an indication of the activity of the vinyl acetate. The contaminating material appeared to be concentrated in the lower boiling fractions. A composite of fraction 1, 2, and 3 boiling between 13C. and 25<'C. reduced the activity of vinyl acetate from one period to three periods. These fractions contained primarily vinyl chloride and acetaldehyde with small amounts of dichlorethane, dichlorethene, propyl chloride, and a trace of vinyl bromide. The ethylene dichloride fraction did not affect the activity of vinyl acetate at all. Results of these activity tests are shown in Table V. The slight effect noted in the fore-fraction, and fractions 4, 5, 6, and 7 may have been caused by acetaldehyde. No unusual and potent polymerization retarder was discovered by the analysis. B. Fore-Fraction from Ethylene Dichlorlde Refining Still The ethylene dichloride used for the synthesis of vinyl chloride at the No. 1 Unit is made and distilled in the vicinity of Building 42. A 2-gallon sample of low boiling fore-fraction from the refining of ethylene dichloride was received. Some of this material was distilled through the laboratory column of 46 theoretical plates. Twenty-nine per cent of the charge boiled below 26C. and contained approximately 70 per cent ethyl chloride and 5 per cent acetaldehyde. A fraction containing-ethylene dichloride and comprising 35 per cent of the charge boiled at Q3C. and had a gravity of 1.258 at 20/15.6 centigrade. Fractions 3 and 4 boiling between 50 and 78C. comprised over 7 per cent of the charge and contained mostly chloroform, carbon tetrachloride, and ethylene dichloride. Other components of the charge were identified as dichlorethenes, dichlormethane, 1,1-dichlorethane, acetone, allyl chloride, propyl chloride, methyl chloride, and formaldehyde. The residue, amounting to about 16 per cent of the charge, contained 90 per cent ethylene dichloride. Complete distillation data are shown in Table VI. V -4- The fractions from the distillation were analyzed on the mass spectrometer. The analyses are shown in Table VII. The analytical data for the original sample obtained from the distilla tion and spectrometer studies are summarized in Table VIII. No inhibitor was found in the sample. TABLE I Sample: Date: Column: Packing: Theoretical plates: Reflux ratio: Fraction No. Fore-fraction 1 2 3 4 5 6 7 8 9 10 11 12 Residue Kettle residue from still No. 2610 8:00 a.m., June 9 1945 Vacuum-jacketed, 30 by 1,560 mm. 1/16-inch nichrome helices 46 5:1 Temperature, C'C. Below 13.2 13.2 to 14.5 14.5 to 20.0 20.0 to 25.2 25.2 to 45.0 45.0 to 47.0 47.0 to 60.0 61.0 to 67.5 67.5 to 70.0(1) 70.0 to 71.5(1) 71.5 to 82.0(1) 82.0 to 82.8 82.8 to 83.5 Above 96 Percentage of charge 1.29 0.27 0.43 1.32 1.20 0.26 0.67 1.20 3.76 1.05 1.98 4.60 57.95 22.51 (1) These fractions were heterogeneous water and dichloride mixtures.. Water was not evident in the sample as received, but during storage rain leaked into the container. i JOG 032 5 O'! \ -5 - TABLE II Standard Distillation of Residue from Table I Cc. I.b.p. 2 5 10 15 20 25 30 Temp., C. 96.0 97.0 97.2 97.9 98.0 98.5 98.8 99.0 Temp., Cc. c. 35 99.4 40 99.6 45 100.0 50 100.0 55 100.5 60 101.1 65 102.1 70 103.5 Cc. "73-- 80 85 90 92 94 94*9 95.2 Temp., C. 105.5" 108.0 110.9 111.8 114.2 119.0 120.0 127.0 TABLE III Mass Spectrometer Analysis of Fraction from Table I Compound Vinyl chloride Acetaldehyde Methyl chloride Carbon dioxide Propyl chloride 1.1-Dichlorethane Dichlorethene Vinyl bromide Allyl chloride Acetone Chloroform Di chlormethane Forefraction 96.7 0.1 0.1 3.0(1) - * v - Composite of fractions 1. 2. 3 ... 76 15 Some Some Some Trace - - Composite of fractions 4. 5. 6, 7 54 - Some 10 20 Trace Some Some Some Trace (1) Probably absorbed from dry ice-acetone cold trap. UCC V "6* TABLE IV Analysis of Kettle Residue from Still No. 2610 Sampled at 8 a.m., June 9, 1945 Boiling Compound Concentration, 56(1) point, C. Methyl chloride Vinyl chloride Acetaldehyde Vinyl bromide Dichlorethene 1,1-Dichlorethane Dichlormethane 0.35 2.8 2.1 Small amount Stoall amount Small amount Trace -24.0 -13.0 20.9 5.8 37.0 57.3 40.0 Allyl chloride Propyl chloride Acetone Ethylene dichloride Propylene dichloride Water Trichlorethane Unidentified residue Chloroform Small amount Small amount Small amount 70.4 8.0(2) 8.0(2) 2.3(2) 4.7 Snail amount 44.6 46.4 56.5 83.7 96.3 100.0 113.0 Above 115 6l.O (1) Based on material recovered from distillation, (2) Estimated composition based on a standard distillation run on the residue from the fractionation. TABLE V Vinyl A.cetate Activity Tests(1) Contaminant(2) None Pore-fraction Composite 1, 2, 3 Composite 4, 5 Erection 6 Fraction 7 Fraction 8 Fraction 9 Fraction 10 Fraction 11 Fraction 12 Residue Heating periods 1 2 3 2 2 2 1 1 1 (1) One cc. of contaminant is added to 22 cc. refined vinyl acetate containing 0.4 gm. dibenzoyl peroxide. The number of 15-second heating periods required to start polymerization is an indica tion of the activity of the vinyl acetate. Vinyl acetate con taining no inhibitory material requires only 1 heating period. (2) Fractions from laboratory distillation of kettle residue. 0 U_< 032503 V -7- TABLE VI Sanple: Date: Column: Packing: Theoretical plates: Reflux ratio: Pore-fraction from ethylene dichloride refining still 6:00 p.m.f June 5, 1945 Vacuum-jacketed, 30 by 1,560 mm. 1/16-inch nichrome helices 46 5:1 Fraction No. Fore-fraction 1 2 3 4 5 6 Residue Temp., C. Below 26 26 to 45 45 to 50 50 to 60 60 to 78 78 to 82 8> - Sp. gr.. 20/l5.6*C(. - 1.254 1.413 1.442 1.290 1.258 1.277 Per cent of charg< 29.1 0.91 2.28 3.67 4.01 4 86 35.30 16.6 TABLE VII t Hass Spectrometer Analyses of Fractions from Laboratory Distillation of Fore-Fraction from Ethylene Dichloride Still Fore- Compound fraction 1 2 Ethyl chloride 70 10 Some Acetaldehyde Dichlorethene 5 Some Some Some 80 ' 90 Dichlormethene Acetone Some Some Some -- - Allyl chloride Propyl chloride - Some Some - Some - Chloroform Some Some Carbon tetra- chloride Some - - Ethylene dichloride(l) ** - - Formaldehyde Some - Methyl chloride * Some 1,1-Dichlor- ethane(1) Some Some Some 3_ Some - 30 Some - 60 4 - Some Some 4 - Some - 80 5 10 - - Some - Some - Some - 10 Some 75 - 6 - Some - Some - Some - 90 - Resi due - Some -- Some - Some - 90 - (1) No distinction was made between 1,1-dichlorethane and 1,2-dichlorethane in these analyses, but the boiling range of the various fractions serves to indicate the particular dichlorethane present. UCC 032504 -8- TABLE VIII Analysis of Fore-Fraction from Ethylene Dichloride Refining Still Concentration, Boiling Compound 95(1) - point, C. Ethyl chloride 21.2 12 Ethylene dichl'oride(2) 52.5 83.7 Acetaldehyde Chloroform 1.5 6.1 20.9 61 Dichlorethenes Carbon tetrachloride Dichlormethane 4.0 0.4 Some 37 76.8 40 l,l-Dichlorethane(2) Acetone Some Some 57.3 56.0 Allyl chloride Trace 44.6 Propyl chloride Trace 46.4 Formaldehyde Some -21 Methyl chloride Some -24 (1) Analysis based on total weight of material recovered from distillation* (2) Although no distinction was made in the mass spectrometric analyses between the two dichlorethanes, the boiling range of the fractions in which dichlorethanes were found indicated that ethylene dichloride was the principal component of the sample. edm H2E- c . IAJ PROCESS DEVELOPMENT LABORATORY ucc 032505