Document 2J3avGvrM3R4k2KbyVBrbgLZg

Inter-Office Memo TENNECO CHEMICALS, INC. To H* B. Carr At Burlington Date September 5, 1969 From Subject F. . Kanzler At Burlington Copy to Monomer Recovery System, Status Report Project No.: 70-001 Reference: Memo to H. B. Carr from F. W. Kanzler, dated 8/20/69 R. S. Cole H. H. Duhamel J. C. Fisher E. J. Hourihan C. W. Johnston N. J. Quist G. I. Rozand P. R. Scarito ^ A. V. M. W. Williams File As outlined in the referenced memo, the Analytical Control Group ha3 initiated a program to investigate and make sugges tions for corrective action in the operation of the monomer recovery system. The problem, as defined, requires answers to the following questions: 1. Are peroxides built-up in the MVC recovery system? 2. What test methods could be used? 3. If peroxides are found, what steps have to be undertaken for removal? The following is the status of work performed thus far to ans wer these questions: 1. IXiring an earlier analysis for peroxides (6/12/69), it was found that the solids from the twin basket strainer between the first stage discharge and the second stage suc tion in the compressor of the plastlsol recovery system yielded a relatively high amount of total active oxygen (0.721$). Production was therefore requested to sample these solids at the highest frequency possible. In addtion, solid built-up in the stripper and the lines to and from the compressors were also pointed out as logical points for Production to sample. Up to now samples from the twin basket strainer and from the copolymer stripper have been analyzed for active oxygen (Table I and II). In addition to the analysis of built-up solids, recovered MVC will also be checked for peroxides. 2. Three different types of methods for peroxide analysis have been utilized. a. Iodine - Sodium thiosulfate titration (analysis level: 0.05-4$ active oxygen) COLORITE 006024 ,2 September 5 1969 b. Potassium permanganate titration (analysis level: 0.054$ active oxygen) c. Reduced phenolphthalein colorimetric determination (analysis level 1-100 PPM active oxygen). 3. Since the evidence indicated in 1.) is that peroxides are built-up in the monomer recovery system, the effectiveness of a caustic wash in reducing these peroxides for Produc tion's information was investigated. A 20$ sodium hydrox ide solution at ambient temperature with no agitation was employed, using strainer basket solids to study the reduc tion of peroxides as a function of time. The same time study was made with solids from the copolymer stripper. Figure 1 shows the loss of active oxygen over a given per iod of time in solids from the twin basket strainer and the copolymer stripper. From the data generated thus far, the following can be concluded: 1. Samples of solids as well as recovered MVC should be con tinuously monitored for peroxide levels. 2. A sodium hydroxide wash of the monomer recovery system at ambient temperature with no agitation will reduce the per oxide level by 87$ after two hours. As seen in Figure 1, no further reduction was evident up to 22 hours at these conditions. When heating was applied for two hours at a range of 50~65C (122-150F) the peroxide was completely reduced. The caustic wash should therefore be carried out at elevated temperatures as high as technically possible (60c). 3- Additional work is required to identify the different types of residual peroxides in the system. As part of this, R & D is trying to obtain more information on vinyl chloride poly peroxides mentioned in a SPI special report dated 2/4/69. An attempt will be made to then identify the peroxides not reduced by the caustic wash. 4. A caustic wash, while beneficial, is temporary and should be considered a "shock" treatment. It is more desirable to prevent the formation of peroxides on a continuous basis. 5. The addition of phenol has resulted in an apparent decrease of the peroxide level at the twin basket strainer. Table II shows the results of peroxide analysis of twin basket strainer samples. This data indicates: a. The addition by Production of caustic (6/15/69) and/or phenol (8/15/69) has been helpful in reducing peroxides in the twin basket strainer. If these peroxides are typical of what may be formed In the rest of the monomer recovery system, the conclusion is that these sources have also been reduced. COLORITE 006025 TABLE I Sample 8/20/69 T.B.S. 8/20/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. Stripper #2 Copoly Stripper #2 Copoly Stripper #2 Copoly $ Active Oxygen 0.2610$ 0.1340$ 0.3128$ 0.2829$ 0.3052$ 0.0945$ 0.0494$ 0.0466$ 0.0521$ 0.0088$ ND ND Time Washed in 20$ NaOH not treated with caustic 5 min. agitated not treated with caustic not treated with caustic not treated with caustic 45 min. not agitated 2 hrs. not agitated 22 hrs. not agitated 22 hrs. not agitated not treated with caustic 1 hr. not agitated 2 hrs. not agitated T.B.S. = Twin basket strainer ND * none detected COLORITE 006026 Sample 6/12/69 8/20/69 8/22/69 8/22/69 8/22/69 8/22/69 8/27/69 8/29/69 9/2/69 TABLE II $ Active Oxygen 0.7210$ 0.2610$ 0.3128$ 0.2829$ 0.3052$ 0.2863$ 0.1814$ 0.1398$ 0.1580$ COLORITE 006027 O COIiORITE 0 0 6 0 2 U 3- - ,September 5 1969 b. It is interesting to note that analyses run on samples from 8/20/69 and 3/22/69 are from the time period of copolymer runs in the plasoisol plant. A reduction of the peroxide level after the conclusion of the copoly mer runs can be seen. 6. To further study the effect of inhibitors on the reduction of peroxides, a small increase of the present phenol addi tion level at the fume scrubber and the use of hydroquinone to better control the recovered MVA has been recommended to Production. The level of phenol and hydroquinone will be monitored to find the maximum reduction of peroxides with the minimum inhibitor level. FWK/rjl Attachments P. W. Kanzler COLORITE 006029 TABLE I Sample 8/20/69 T.B.S. 8/20/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. 8/22/69 T.B.S. Stripper #2 Copoly Stripper #2 Copoly Stripper #2 Copoly $ Active Oxygen 0.2610$ 0.1340$ 0.3128$ 0.2829$ 0.3052$ 0.0945$ 0.0494$ 0.0466$ 0.0521$ 0.0088$ ND ND Time Washed In 20$ NaOH not treated with caustic 5 min. agitated not treated with caustic not treated with caustic not treated with caustic 45 min. not agitated 2 hrs. not agitated 22 hrs. not agitated 22 hrs. not agitated not treated with caustic 1 hr. not agitated 2 hrs. not agitated T.B.S. = Twin basket strainer ND = none detected COLORITE 006030 Sample 6/12/69 8/20/69 8/22/69 8/22/69 8/22/69 8/22/69 8/27/69 8/29/69 9/2/69 TABLE II $ Active Oxygen 0.7210/ 0.2610$ 0.3128$ 0.2829$ 0.3052$ 0.2863$ 0.1814$ 0.1398$ 0.1580$ COLORITE 006031 COLORITE 006032 20 X 20 TO THE INCH 4G 1240 i * lO INCHES :f `'i u S KEUFFEL ft E35CR CO.