Document 2q2vV0LaN5p65ebEExJxeypxL

I Monsanto CompanyOrganic Chemicals Division St. Louis Research Department SAFETY REVIEW COiVf,\!! APPROVED Ve rnal APPROVAL DATE JANmSS1 DO NOT REPRODUCE, TRANSFER, STORE OR DESTROY RETURN RtPCRi TOi OnOe.N.0 ..cS ARCH DEPARTMENT TttHrslCAL lNrO;<,,iA'(ION GROUP 1700 SOUTH SECOND STREET St. Louis Research Report No. P-1516 TENTATIVE PROCESS FOR MCS 717 (Low Temperature Capacitor Fluid) Job No. 2-21-760.01-1630043 Date: January 17, 1969 Written by: Work done by: J. D. Sullivan J. D. Sullivan J. F. He'rber HONS 057640 DISTRIBUTION OF REPORT NO. P-1516 1. 2. 3. 4. 5. 6. 7,. -iifi. 9. 10. 11. 12. 13. l4. 15. 16. 17. 18. Kile Technical Reports Library Extra Extra Extra Clrc. to Organic Res. Managers/Library J. D. Sullivan/J.F. Herier W. R. Richard Patent Department - J. E. Maurer R. H. Munch 0. W. Miller - Anniston H. F. Ray - Krunmirich Standards Dept. - Anniston Plant Standards Dept. - Anniston Plant Standards Dept. - Anniston Plant Standards Dept. - Krummrlch Plant Standards Dept. - Krurnrich Plant Standards Dept. - Krummrlch Plant This report contains confidential Information which Is the property of the Monsanto Company and which shall be disclosed only to duly authorized persons. The recipient is held accountable for the filing and safe custody of the report which must be returned on demand. 0NS 05764i TABLE OF CONTENTS Page No. INTRODUCTION................................................................. 1 SYNOPSIS OF PROCESS .............................................. 1 BILL OF MATERIALS.................. 1 PROCESS IN DETAIL..................................................... 1 DISCUSSION OF IMPORTANT VARIABLES................. 3 MATERIAL SPECIFICATIONS, ANALYTICAL METHODS................................................... 6 TOXICITY AND HAZARDS.............................................. 7 POLLUTION CONTROL ................................................... 8 HONS 057642 -1- INTRODUCTION This report Is a Tentative Process for the manufacture of MCS 717, a low temperature capacitor fluid, prepared by the isomerization of a selected chlorinated biphenyl, it will supercede the process for MCS 717 (Report #P-1501) which was successfully demonstrated in the JFQ Pilot Plant during October, 1968. Demands for larger quantities of this pro duct necessitated the modification of the process so that the reaction could be adapted to existing Aroclor production facilities at WGK and/or Anniston. SYNOPSIS OF PROCESS Crude undegassed Aroclor (spec. grav. at 25 V25C-1.3450 to 1,3500) is l3omerized with AlCls (l#-175C-2 hrs), degassed with plant air (1.5 NN max.), neutralized with calcium hydroxide and straight-takeover distilled. The distillate is treated with Attapulgus earth (0,5#-2 hrs-6oC) followed by a Porocel filtration* into thoroughly cleaned and rinsed double phenolic lined drums. * see Bill of Raw Materials BXLI, OF RAW MATERIALS The following weights of raw materials are required to pro duce 100 pounds of MCS 717. im pounds Crude Aroclor Aluminum Chloride Calcium Hydroxide Attapulgus Earth Porocel-60 Mesh** 110 1.1 0.5 0.5 1.0 -G---a---ll-o---n--s-9.82 -l-b---s--/-gS-a---l-l-o---n-- - , _ 11.20 _ ',,. * This medium is used to pack the filter for the removal of Attapulgus earth from finished product. PROCESS IN DETAIL (1) Isomerization To a reactor, equipped with a stirrer and a condenser leading to a HC1 scrubber, is charged 110 pounds of crude undegassed Aroclor (1.3450 to 1.350 at 25/25 C) and 1.1 pounds of dry Aids. The reaction mixture is held at 175-l80C for 2 hours to accomplish the isomerization. If heating facilities are r.ot available to attain these isomerization temperatures, the chlori nation of the original biphenyl can be flnished-off at l80C to 190C to suoply residual heat for the hold period. HONS 057643 -2- (2) Degassing The batch Is then cooled to 150C and degassed with the Introduction of plant air until the acidity of the crude Is reduced to 1.0 NN-1.5 NN. This was accomplished In the laboratory, in 2 to 3 hours at flow rates equiv alent to 1.0 cu.ft/hr/lb to 0.5 cu.ft/hr/lb. After the batch has been degassed, the crude Is transferred to the distillation equipment. (3) Neutralization After the transfer of the crude to the distillation still is complete, 0.5 pounds of calcium hydroxide is slurried Into the batch at 150<'C. The mixture Is stirred at 150C until the acidity of the crude Is reduced to 0.5 NN maximum. In the laboratory, this reduction in acidity was accomplished In les3 than an hour, under these conditions. (4) Distillation The crude Is distilled Into a stirred receiver, equipped with a constant recording specific gravity device. The distillation is continued until the specific gravity of the product approximates the specific gravity of the starting crude within + 0.005 units at 25*C/25C. In the final stages (10# Fo 15#) of the distillation, the temperature of the condensing water Is Increased to 60-65C to allow the more viscous distillate to flow into the stirred receiver. In the laboratory, this material was distilled through a 1 1/2" punched column in a pot temperature range of 207 to 230C at 30 mm. The vapor temperature at the top of the punched column varied from 190 to 225C at 30 mm during this distillation. A spray-trap type column is sufficient for this operation If the last 10# to 15# of the product Is carefully distilled to prevent excessive entrainment of high polymeric mater ials from the pot residue. Laboratory yields of distilled product ranged from 90 to 94# of the still charge. The residue from this isomerlzed crude contains approximately 3 times more solids than the residue from a regular Aroclor distil lation. . HONS OSl*'*'* -3- (5) Attapulgus Earth Treatment To the well mixed distillate Is charged 0.5 pounds of activated Attapulgus earth and the resulting slurry Is stirred for 2 hours at 6oC prior to a Porocel filtra tion* at 60C to 65C. The Attapulgus earth and the Porocel, used in this treatment, are activated by roast ing the absorbents for at least 4 hours in a 250*0 oven. * see Bill of Raw Materials , (6) Packaging The filtrate represents an electrical grade fluid and extreme care must be exercized in Its handling, sampling, packaging and storage. Trace contaminations, espec ially ionic impurities, will completely deteriorate the electrical properties of the fluid and make it un acceptable for the application. Transfer lines for the filtrate must be thoroughly cleaned, dried and flushed with the finished fluid. The same successive flushes may be used to rinse the double phenolic lined drums for fluid storage. The rinses are reintroduced Into the process during a successive Attapulgus earth treatment. If the finished product does not attain the specifica tions of an electrical Aroclor (power factor and resis tivity) the fluid is reexposed to another Attapulgus earth treatment. When the drums are transferred to storage, care must be taken not to chip the Internal phenolic coating by rough handling. DISCUSSION OF IMPORTANT VARIABLES (1) Isomerization The main feature of this new capacitor fluid Is a 10 to 15"C reduction in the pour point for low temperature applications. Because of this specification, It Is important that the directly chlorinated Aroclor has a ' specific gravity of 1.3450 to 1.3500 at 25/25C before using the raw material for this process. Chlorinated biphenyls, adjusted to the desired specific gravity by the "back-blending" of Aroclors, cannot be used In the preparation of MCS 717. Specific gravities on the well mixed crudes are determined in standardized pycnometers. M0NS 057645 Hydrogen chloride Is an Initiator for the dry AlCla catalyzed Isomerization, The crude undegassed Aroclor Is saturated with by-product HC1 and no effort should be made to degas the material before the isomerization. Degassing Regular plant air is used for degassing In the pro duction of Aroclor. Laboratory experiments show that dry air, dry nitrogen or air saturated with water vapor may be used in this degassing operation. Neutralization After the crude has been degassed and transferred to the still, calcium hydroxide is added to the batch to complete the neutralization and to protect the Iron equipment during the distillation. Calcium hydroxide is also added to the still pot charge to Improve the quality of the distillate by taking up any HC1 which may form, due to slight decomposition of the fluid, during the distillation. Furthermore, the Ca(0H)2 pro motes the removal of any Cl-groups which have reacted by addition rather than substitution, in the original biphenyl chlorination. This reduction In labile chlorine Improves the chloride stability of the finished fluid for electrical applications. Distillation ' The most important factor in this distillation Is the realization that Aroclors are not pure materials. Aroclor contains innumerable, closely boiling Isomers having widely varying fluidities. As the distillation temperature increases, the chlorine content and the viscosity of the distillate increases. These are the reasons for preheating the condensing water and agita ting the contents of the receiver. The higher boiling isomers affect the fluidity of the product throughout the entire viscosity range but especially at the pour point. Isomerization substantially increases the specific gravity of the crude Aroclor even after the neutraliza tion solids are removed. An additional purpose of this distillation is the separation of the higher isomer products from the polymerized materials formed during the Isomerization of the crude Aroclor. Available spray-traps and/or demlBters are recommended for this operation. If a highly effective column is used, repre sentative isomerized Aroclor cannot be obtained at reasonable temperatures and pressures. Increasing the specific gravity of the starting raw material would not overcome this distillation end-point difficulty. This HONS 057646 -5- alternate gives a higher viscosity fluid at the desired specific gravity level and is accompanied by substantial yield losses in the still residue. During the isomerization and degassing, A1C13 as wall as acid tars sublime onto the free-board of the reaction vessel. For this reason it is imperative to transfer the batch to another pot before distilling the crude. The crude can be distilled from the same reaction vessel if the batch is held at reflux, under reduced pressure, until the return flow is colorless and the acidity of the batch is 0.5 NX or less. After the isomerization run is completed the plant equipment may be cleaned out with a regular run of Aroclor 1248, It la recommended that this batch of Aroclor 1248 be segregated from the regular Aroclor production and be used for the formulation of Pyaraul fluids. (5) Attaoulgus Earth Treatment Attapulgus earth treatments are very effective in lower ing the power factor and increasing the resistivity of electrical grade Aroclor fluids. Samples of the finished fluid, submitted for electrical properties, must be withdrawn through specially cleaned pipettes or thiefs into specially cleaned amber bottles with aluminum foil-lined caps. The finished fluid as wall as the inner surfaces of sampling devices and- sample containers must be protected from outside contamination and must not be touched with "salty" human hands. If the finished goods is stored for a prolonged period of tine in plant equipment, awaiting analyses and/or packaging, It Is recommended that the batch be blanketed with a nitrogen atmosphere. In the pilot plant demonstrations of MCS 717 the filters were lined with Porocel (60 mesh) to speed the flow rates and eliminate possible contaminations by other suitable filter aids. In large scale production, the passage of the distilled material through a fixed bed - of Porocel would be a suitable purification for this product. . (0) Packaging The same precautions employed in handling and sampling of electrical fluids must be observed in their packaging and storage. Double phenolic lined drums are satis factory for general storage and local hauling. For HONS 057647 -6- long distant shipping, invoivir.3 the usual rough handling, a double epoxy-phenolic lined drvjn is recommended. These' drums may be purchased from Bradey-Voornan (Chicago) Nosco (Granite CityJ or Florida Drum Company (Pensacola, Fla,). MATERIAL SPECIFICATIONS, ANALYTICAL METHODS A. Material Specifications U) Ravr Materials (a) Crude Aroclor Sped flc Gravity 1.3450 to 1.3500 at 25/25C (b) Aluminum Chloride Code #11560 (c) Calcium Hydroxide (Hydrated Lime) Code #38800 (d) Attapulgus Earth Code #19400 (e) Porocel (60 mesh) Anniston (2) Finished Product Specific Gravity at 25/25C within 0.002 to 0.005 units of crude Viscosity at 210F at 100? at +20 F 1.9 to 2.2 cs. 10 cs to 11 os 600 cs to SCO cs Pour Point -30C min. (-3SC to -36 C typical) Dielectric Constant 100C 4.3 min. Resistivity 100C 5000 x 10s ohm-cm Power Factor 100C '' - 60 cycles 0.3; 100 cycles 0.1)5 WGK Method Number Inorganic (Free) Chlorldesreport Hydrolysis Stability Test 0.2 ppm (max) T2092 T20S7 ' ' Monsanto Stability Test 0.02 ppm (max) Thermal Chemical Chlorides 0.5 (max) 11,503 12,722 KONS 057648 7- The fluidity of the finished product he 3 not been firmly established but reasonable ranges for viscosities and pour points are listed above. These ranges were determined by laboratory runs and pilot plant demon strations . The effects of higher boiling Aroclor isomers on the fluidity of the product increases as the temperature is reduced. However, low temperature viscosities (l.e. +20F) have been very consistent with pour point determinations. Furthermore, low temperature viscosities are more accurate, more reproducible and more meanlngful than absolute pour point determinations. Pour points were determined in regular ASTM tubes sus pended from a specially designed holder, which was mounted inside a frost free cold chest (Thermotron Corp.), equipped with accurate temperature controls. By means of an external rotating device, the tubes were rotated, through a 45 angle, from the vertical position to a horizontal position and the timing for the test was started. Flowing motions, on the surfaces of the oonstant temperature fluids, were observed through a frost-free sight glass. The lowest temperature, at which flow waB observed within 5 seconds (ASTM), was desig nated as the pour point of the fluid. TOXICITY AND HAZARDS Aroolor is a liquid, under normal conditions, having a medium toxicity range for liquid ingestion and a high toxicity range for vapor inhalation. The maximum allowable concen tration is 1 mg/cublc meter. This material can cause derma titis, systemic poisoning from the fumes and yellow atrophy of the liver,- There are skin, mucous membranes and eye irritation encountered in handling Aroclors. However, the crude Aroclor, used as the starting material in this process, is saturated with HC1. Hydrogen chloride is a gas and is very toxic. It is hazardous to teeth, skin, eyes and mucous membranes. Aroclors offer no fire hazard. Aluminum chloride reacts with small amounts of water with such violence as to start a fire in the presence of organic materials. Containers of this material should be stored completely enclosed or under a dry inert atmosphere. It reacts with moisture in the skin or mucous membranes to form a strong acid which can result in severe burns. Avoid inhaling the dust and wash affected areas with large amounts of water. Wear rubber gloves and goggles when handling this material. . HONS 0576*9 -8- Calcium hydroxide Is not dangerously toxic but is very hazardous to the eyes. It will burn the skin and the dust will affect the mucous membranes. In general, Attapulgus earth is not toxic. Persons handling large amounts of this absorbent should wear a respirator to avoid Inhalation of the dust which contains silica. POLLUTION CONTROL The following weights of waste materials will have to be disposed of from the various process steps in the production of MCS 717. Pounds of Waste Materials per 100# MCS 717 Process Steps Pounds Isomerization & Degassing Neutralization Distillation Attapulgus Earth Treatment Filter Cake 0.01# HC1 None 5# to 10# Residue 0.5# Attapulgus 1.0# Porocel 1.5# Residual HC1 contained In the original crude and the small amount of HC1, evolved during the Isomerization, will be dissolved In a water scrubber and sewered. The still residue. Including chlorination tars, Isomerization polymers. Iron, aluminum and calcium salts along with highly chlorinated biphenyl. Is transferred hot to a suitable container and sent to the toxic dump. TKe" filter cake, from the Attapulgus Earth treatment, will go to the solid disposal interment. ms 1/17/69 File Copy Approved by Manager of Research: J. D. Sullivan W. R. Richard (Date) M0NS 057650