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A-/?* 70-0 0) INTER-OFFICE COMMUNICATION TENNECO HYDROCARBON CHEMICALS July 31, 1969 TO: FOR: FROM: RE: Laboratory Files D. J. Cleckley G. R. Harvey ' Calibration change for VCM Light Ends Analysis SUMMARY A sample of our VCM from a hold tank was analyzed by chromatography for the light hydrocarbons by several laboratories. The results indicate the THC laboratory analyses have been high by a gross amount. On Friday, August 1, 1969, it is planned to change the THC factors to bring them in line with the ocher laboratories. The sample analyzed by the laboratories will be retained to routinely calibrate the chromatograph. In addition a gas blending kit has been purchased so that blends can be made to recheck the standard. INTRODUCTION Propadiene, methyl acetylene and 1,3 butadiene are impurities of our vinyl chloride monomer product which must be kept below the specification level required by Tenneco Plastics Division. The impurities are in the PPM range. There have been disagreements in chromatographic analyses for these components among laboratories, both inside and outside the company. The economic consideration of the acceptance or rejection of an entire car load of product has required that the analysis differences be resolved immediately. COLORITE 005856 * 2- - DISCUSSION As a basis for comparing analyses among laboratories, and in order to check reproducibility of our analyses, a cylinder of hold tank product was collected. Samples from this cylinder have been analyzed by car laboratory, the Tenneco Plastics laboratory and by three laboratories of vinyl chloride producers outside the company: Dow Chemical Company, Freeport; Pittsburgh Plate Glass Company, Lake Charles and Continental Oil Company, Lake Charles. The results are tabulated in Table I. A comparison of the results shows very good agreement among the outside laboratories. Our laboratory reported answers much higher than the outside companies -- five times higher in the case of propadiene. Tenneco Plastics was in closer agreement with the outside laboratories but was two and one half times higher for propadiene. The calibration factors for the THC laboratory analyses were derived in tne Fall of 1968 and based on Dow's analyses of various samples. Tne expectant of taxing"TTow1 s analyses was used because it was believed they would be satisfactory. Tenneco had just become aware of the importance of these impurities while Dow was experienced in vinyl chloride monomer production. We did not make a primary standard. it the TKC metnod of analysis, a liquid sampling valve is used to introduce me sample into the chromatograph. The separation is on a traoury- pr.osphate column at loC to 2CC. Components are detected by hydrogen re are severe- possible reasons why sensitivity of the THC o: C c__cC and so the temperature can change with room temperature change. (*0 4 mu_tv electrometer cable was recently changed. (3) Carrier flow rate is dirricult.to measure and Se _j not checked frequently. (4) Human error hut been observed in measuring the relatively narrow peak widths. I personally visited each of the outside laboratories to deliver the Mr. iiny Coudcau was the chemist directly involved at ix.r during the v_^tw -o rreeport on July 15, 1969. Messers Jack Skaggs and Rodney Webb at were also interested in the problem. Mr. buddy hann was the host at Hittsourgn Plate Glass with Mr. Bob Pertuit giving his full attention to our COLORITE 005857 sample. Mr. Ed Feveto was Che chemist at Continental Oil. Messers Pertult and peveto were taken to lunch during the visit to Lake Charles on July 17, 1969. The most obvious observation was that each laboratory used a different method. The only common points were gas sampling and flame ionization detection. Dow vaporized the sample across a heated valve, Pittsburgh Plate Glass across an unheated valve and Conoco across capillary tubing immersed in oil at room temperature. Dow and PPG sampled with a commercial valve while Conoco used a syringe. Dow did not know their sample size, PPG used 0.5ml and Conoco 5,0 ml. Dow separated on a tributyl phosphate column at 20C thermostatically controlled; EEC separated on an undisclosed column with programmed temperature beginning at 50C; Conoco separated on bis2 - (2 methoxyethoxy) room temperature. Dow measured peak height, PPG measured peak area as we do and Conoco measured peak area electronically by an Infotronlcs integrator. Dow corrects their calibration factors once per week by running a standard blend, as does Conoco once per shift. PPG does not use a standard blend but Instead accounts for all components and normalizes to 100Z, using relative response factors, CONCLUSION The analyses of the outside laboratories would appear to be approximately correct because of the remarkable, uncollaborated agreement using diverse techniques. If this is so, the THC laboratory should correct its method to be in agreement with the others. RECOMMENDATION Unless reasons are presented otherwise, the VCM analysis method'of calculation will be changed Friday, August 1, 1969 to bring the analyses in agreement with the outside laboratories. The analysis of each component will be reduced by the ratios shown in Table I between the average analysis of outside laboratories and the THC laboratory analysis. An exception is propadiene factor which has already been reduced by one third on July 23, 1969, based on preliminary data. The propadiene reduction on August 1 plus' the previous one third reduction will equal the ratio shown in Table I. A new scale will be provided for the VCM Control Room process analyzer. COLORITE 005858 TABLE I COMPARATIVE ANALYSES, VCM STANDARD BLEND #2 Hold Tank Sample, July 11, 1969 LABORATORY THC Tenneco Plastics Dow PPG_______Conoco Average, Ratio, outside (outside labs__\___________labs) /THC DATE ANALYZED July, 1969 propane Propylene Isobutane Propadiene Butane Butene - 1 Methyl acetylene Methyl chloride 1,3 Butadiene 18-22 23 32 11 11 42 107 49 3 <1 3 i <1 82 18 9 93 15 0.6 1\.9 i. 19.7 0.8 0.8 2. 12 4 17 17 17.6 0.5 1.8 0.8 18.6 1 97 33 0.6 2. 1. 19. 0.8 0.8 1.6 9. 4. 0.20 0.18 0.25 0.18 0.27 . 0.27 0.20 0.20 0.44 All data on ppm by weight. COLORITE 005859 'ffjitx&di Ufa c"'v',w ^-C ---'**&***-/- -2IT 't yuyj^ zImxa^ ''fort O^'fdd $) '- JUL 251969 COLOR!TE 005860 C4 f- V An analysis of Tables I and II show the following: In those systems employing 0.050 phm Lupersol 11 as the catalyst, there is no noticeable change in the initial polymerization kinetics l/kSLV\ wlaioh i -fCirVt<) yCcxf .on the t3jc^e of water used in-making up the suspension*^).' <fiy distilled cold a**d hot demineralized water, and well water,werrymsed. The conductivity of the distilled and deionized waters were about the same (0.5--2.0 ppm as NaCl) while the conductivity of tjie well water jags*exceeded our scale reading of 20 ppm as NaCl. (I am informed that the conductivity of well water is about 2,000 ppm as NaCl. The metals present in well water must consist of less than 5 ppm Fe-1"1" according to our results. In all probability, the major impurities in well water r , r o** are probably Ca , Mg , Na, K+ and/or other monervarlgn-t metals.) It should be noted that the use of recovered, rather than virgin, MVC results in a slower kinetic rate of polymerization. ++ <>/ Upon the addition of Fe , the degree of conversion a^beT two hours hegii*ttg--accelerates markedly. The addition of one drop of concentrated HC1 to the suspension system to lower the pH. from about 6 to 2.5 also 1I increases the percent conversion when low amounts of Fe are added since the presence of dydrogen ions usually catalyses a Redox system. Fe + RiOORa ff-\> _Fe+++ + Rj 0 + Re0` The presence of about 150 ppm Fe"^ (added as FeCLE) drastically increases the percent conversion 4--5 times that of the control. Increasing the Fe level to 500 ppm does not appear to increase the degree of conver sion over that noted when 150 ppm Fe++ is added. The addition of Fe+++ (rather than Fe++) has a much less marked effect on the polymerization kinetics. The increase in kinetic rate noted when Fe1TT (as FeCl3) is added can be attributed to a^catalytic effect in the decomposition of Lupersol 11 and/or trace impurities of _i -I Fe -. COLORITE 005861 2- - It must be noted that the use of Fe^ (5--500 .ppm) results In a thin coating appearing on the sides of the coke bottles which is fairly easy to clean off by scrubbing. Such a coating is not evident when Fe is the additive. Also, the addition of Fe`H' results in dumping of the resin particles,* the higher the Fe++ level, the more difficult it is to break such clumps although no really extremely hard-to-break aggregates are formed. The higher the Fe"^ level, the darker is the color of the dried resin. Addition of Fe does not cause a film to be formed on the inner surface of the Coke bottle as does the use of Fe++. In addition. |Umping is noi|evident in those systems where Fe+++ was used, but the or of the dried resins wherein Fe+++ was added are slightly darker than those having equibalent amounts of Fe++++ in the polymerization formula. Table II indicates there is no change (other than a darkening in the dried resin) in the degree of conversion after the first few hours when lauroyl peroxide replaces Lupersol 11 as the catalyst. COLORITE 005862 TABLE I Effect of Various Ingredients on the Percent Conversion of Vinyl Chloride After Two Hours Reaction Time Using 0.050 phm Lupersol 11 as Catalyst 133F. Formulation Changes A % Conversion ;,-pH 2.5 / Cold Deionized H2O Cold Deionized H2O + Recovered MVC Well Water 4 (-5*) Well Water + Recovered MVC Recovered MVC 5PPM Fe- (pH = 5.7) (-5*) (-5$) +5% 5PPM Fe4 + Recovered MVC ^>PM Fe4 + Recovered MVC + Cold Deionized H20 5PPM Fe4 5PPM Fe4 5PPM Fe4 (PH = 2.5) (pH = 2.5) + Recovered MVC (pH = 2.5) + Recovered MVC + Well Water 5PPM Fe4 (pH = 2.5) + Recovered MVC + Well Water + 0.5PPM Ionol 5PPM Fe^ (pH = 2.5) + 0.5 PPM Ionol 50 PPM Fe** 50 PPM Fe4-*" (pH = 2.5) 150 PPM Fe** 150 PPM Fe*4" (pH = 2.5) < 500 PPM Fe*4" 500 PPM Fe*4" (pH = 2.5) 500 PPM Fe^"* + Recovered MVC v ppm Fe"1^" f0 ppm Fe*** 500 ppm Fe***" (pH 2.5) +10% +5% +5% +5% +10% +100% +150% +4oo--550# +400--550$ +4Q0--550JS +400--550# +300--400# +25# +50# +50# COLORITE 005863 TABLE II Effect of Various Ingredients on the Percent Conversion of Vinyl Chloride of Vinyl Chloride After Two Hours Reaction Time Using O.I85 phm L2C>2 as Catalyst at 155F. Formulation Changes pH = 2.5 50 ppm Fe++ 150 ppm Fe44 500 ppm Fe44". 500 ppm Fe44 (pH = 2.5) 50 ppm Fe44 500 ppm Fe44 500 ppm Fe444 (pH =2.5) A % Conversion -- COLORITE 005864