Document 8qJwRn941y68LVEQNLDkVZ7o

t = .... TENNECO CHEMICALS, INC. To FftOM Subject Dr. R. T. Gottesman Mr. P. J.~Patel AT Piscataway AT Flemington PLANT STRIPPING TRIALS - FEBRUARY d*te March 19, 1975 copy to Copy Listing - To take advantage of Pilot Plant manpower availability, as a result of the Flemington Plant shutdown for copolymer conversion, a Burlington Plant experimental stripping program was initiated to establish stripping con ditions for dispersion latexes and 315 copolymer slurries. The program also included stripping evaluations of homopolymer products. Starting February 2 and continuing through March 8 the Polymer Pilot Plant and Engineering groups carried out an around-the-clock five day per week stripping program in the Burlington Plant. Conclusions A. 315 Copolymer The double spike thermal treatment as described in Table I with vinyl acetate monomer (MVAC) add back to 315 slurries has not produced the desired VCM reduction. However, these techniques have produced a 315 dried resin having residual vinyl chloride (MVC) of 10-15 ppm with very little color deterioration. The residual vinyl acetate content of the resin prepared using the MVAC and back technique was abnormally high (0.5%). At higher agitations the MVC content in 315 slurries appeared to be reduced. B. (X) Dispersion Latex Stripping - New Agitator Study The vinyl chloride content in most latexes was substantially reduced by using a new agitator set at 20 rpm in conjunction with nitrogen sparging. The latex filterability as tested by lab leaf filter was not impaired using this procedure. The latex MVC reductions are a.s follows: 1730 Latexes 1755 Latexes 1757 Latexes - In 8-10 hours, MVC levels were reduced to < 850 ppm. - In 10 hours, MVC levels were reduced to < 1,340 ppm. - In 10 hours, VCM levels were reduced to < 1,700 ppm. (II) MVC Decay - Dispersion Resin Aging The aging of dried dispersion resins stored in our Burlington ware house showed a residual MVC content of nondetectable to < 10 ppm for most resins within 7-10 days. COLORITE 017290 2- PLANT STRIPPING TRIALS - FEBRUARY March 19, 1975 C. Homopolymer Stripping Study 200-2 Blend tank sparging, without vacuum, was relatively ineffective in that the rate of VCM reduction was slow. The MVC reduction reached a level of 476 ppm during a 14 hour time span from an initial level of 1,437 ppm. Future Plant Study A. 315 Copolymer Further testing is planned in the latter part of March to evaluate MVAC add back stripping at higher stripper agitation. Due to the poor mixing ability of our current equipment, the MVAC add back stripping technique offers very little advantage. B. Dispersion Resin - Latex Stripping The study will investigate the effect of increased agitation (45 rpm) and sparge rate on the MVC removal, latex stability and filterability. Discussion A. (I) 315 Copolymer Two stripping trials were implemented. In the first trial, five sequential batches of 315, prepared in the copolymer plant, were treated as follows: Individual batches transferred into the stripper were heated to 190F using live steam and cooled to 165F by evaporative, vacuum and full jacket cooling. At 165F, 57. MVAC (1200 lbs.) was added in three 400 lbs. increments at five minute intervals. The MVAC soaking cycle was 30 minutes at 165F without recovery; then heated to 190F with vacuum and cooled to 165F with 300 gallons of cold water injection, evaporative and full jacket cooling. In the second trial, the same procedure was followed without the addition of MVAC. The results of these tests are summarized in Table I and Table II. The residual MVC content in the resin was 10-15 ppm, but the MVAC content was abnormally high. The lack of batch to batch reproduci bility of residual MVC observed in Table II is thought to be due to poor mass transfer of vinyl chloride from the polymer particles into the aqueous phase which contains the MVAC. The reproducibility may improve if higher agitation and lower MVAC soaking temperature (< 150F) is used. COLORITE 017291 PLANT STRIPPING TRIALS - FEBRUARY 3 March 19, 1975 (II) Higher Agitation 315 Stripping (No MVAC Add Back) In this study 315 slurries were subjected to 190F using steam and cooled to 165F using evaporative, vacuum and full jacket cooling. Stripper #3 was used for the improved agitation study. In Table III, MVC contents in the slurries under improved mixing conditions are displayed. The study of the double spike thermal technique with MVAC add back will be evaluated in stripper #3 during the latter part of March. B. (I) Dispersion Resin - Latex Stripping A low shear, high pumping rate agitator was installed on stripper #4 and set at a speed of 20 rpm for the initial trials. Seventeen thirty (1730), 1755 and 1757 latexes were stripped utilizing 15-20 in, Hg. vacuum at 100-110F, and nitrogen sparge. The completed tower batches were stripped for two hours with the vacuum recovery system and then switched to the steam jet system. Foaming was con trolled by the periodic addition of tributyl phosphate defoamer through a spray nozzle. The residual MVC results are summarized in Table IV and in Graphs 1 through 3. It can be seen that a significant reduction in residual VCM content without deteriorating lab leaf test filterability was obtained. The 45 rpm study planned in March should further improve the rate of VCM reduction. (IX) MVC Decay - Dispersion Resin Aging Pallets of 1750, 1756, 1755, 1757 and 0565 were sampled daily for the analysis of residual MVC. It was found that for most resins MVC content decays to N.D - 10 ppm level within 7-10 days. (Ill) 200-2 Blend tank sparging MVC data is shown in Table V. Miscellaneous In addition to the previously discussed projects, the Pilot Plant has assisted Process Engineering on the following projects: (i) (ii) (iii) Monitoring of 315 special batches, Monitoring of 903 blending system for dispersion foam resin, and Analysis of slurries and latexes for MVC contents. PJP/amp Attachments P. J. Patel COLOR!TE 017292 TABLE I COPOLYMER STRIPPING 315 TEST DATA DOUBLE SPIKE EXPERIMENTS Samole Source Residual MVAC Average MVC pon MVC Range Resin Color L ab Control Drier -- 78.3 69-84 89.4 -1.1 3.2 'G' MVAC Add back Double Spike Drier 5034 'H' No MVAC Add back Double Spike Drier 1196 13.8 4.5-27 88.6 -0.7 4.5 10.8 7.7-16.1 89.1 -0.7 4.5 30 Min, COLOR!TE 017293 TABLE II RESIDUAL HVC EVALUATION 315 SLURRIES DOUBLE SPIKE EXPERIMENTS 'G' Series 5% MVAC Add Back Sample Residual MVC (ppm) MVAC (ppm) G-l 290 4,289 G-2 43 5,565 G-3 G-4* 1,290 141 9,006 10,437 G-5 G-6 . 231 88 4,912 7,048 G-7 G-8 - 697 69 15,007 9, 728 G-9 G-10 . 990 14 7,295 7,679 Blend Tank 290 8,241 'R' Series No MVAC Sample Residual MVC (ppm) MVAC (ppm) H-l H-2 473 104 7,029 2,079 H-3 H-4 331 20 2,832 1,237 H-5 150 3,736 H-6 89 1,897 H-7 H-8 362 95 3,614 1,939 H-9 H-10 725 35 3,864 2,030 Blend 58 2,198Tank "315 Slurries" 1st Spike 2nd Spike MVC Average (ppm) 'G' 'H' 700 408 71 69 COLOR!TE 017294 TABLE III IMPROVED AGITATION VS. MVC (ppm) 315 SLURRIES PRELIMINARY DATA Normal Agitation Stripper #2 After First Spike ("H" Trial) MVC(ppm) Average 408 a) 150 - 725 Improved Agitation Stripper #3 MVC Csmnl Average Range 234(2) 167 - 302.4 (1) Average of 5 batches. (2) Average of 4 batches. COLORITE 0X7295 TARLE IV NEW AGITATOR STRIPPING STUDY DISPERSION LATEXES 1730 Latexes 92 94 93 96 97 98 99 2 Hours 6,493 6,086 6, 350 3,569 4,637 9, S53 5,476 Residual MVC (pom) 6 Hours 8 Hours 10 Hours % Moisture Cake -- --" 1, 955 1,392 3,217 2,227 ___ 256 850 -- -- --- 5,630 -- -- -- -- -- 25.3 28.8 22.3 26.7 25.8 23.3 22.9 Comments No Sparge Sparge 7.3 era Sparge 7.3 era Sparge .25 era Sparge .25 era Sparge .25 CFM Sparge .25 CFM 1755 Latexes 86 10,814 958 22.6 Sparge 25 CFM 85 4,140 -- -- 1,340 23.1 No Sparge 1757 Latexes 89 90 91 13,428 10,442 9,792 -- "" " 9,186 23.5 No Sparge -- 1,642 22.1 Sparge 1.5 CFM 1,590 25.0 Sparge 7.3 CFM COLORITE 017296 TABLE V HOMOPOLYMER STRIPPING EXPERIMENT 200-2 BLEND TANK SPARGING Sample Hours MVC (ppm) Slurry 95-1 0 1,437 95-2 2 1,131 95-3 4 1,015 95-4 6 787 95-5 10 626 t 95-6 14 476 Dry Product = 280 ppm Stripped 200-2 with proper D.B.T. 900 ppm Note: Biend Tank #5. Nitrogen Sparge Rate 50. SCFM. COLORITE 017297 K C L ffF tL ft EStlEJt CO . O il | 3 CYCLE! X 70 O lV ttlO ttt COLORITE 017298 COLORITE 017299 COLOR!TE 017300