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A BATCH POLYSTYRENE REACTOR RUNAWAY: A CASE HISTORY BY RONALD J. WILLEY, PhD. PE. NORTHEASTERN UNIVERSITY PREPARED FOR SACHE A PRODUCT OF THE CCPS-AICHE NEW YORK, NEW YORK 2000. ST. LAWRENCE RIVER. PROVINCE OF QUEBEC CANADA. ISLE OF MONTREAL. LACHINE CANAL. LASALLE. THE ACCIDENT
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A BATCH POLYSTYRENE REACTOR RUNAWAY: A CASE HISTORY BY RONALD J. WILLEY, PhD. PE. NORTHEASTERN UNIVERSITY PREPARED FOR SACHE A PRODUCT OF THE CCPS-AICHE NEW YORK, NEW YORK 2000
ST. LAWRENCE RIVER PROVINCE OF QUEBEC CANADA ISLE OF MONTREAL LACHINE CANAL LASALLE
THE ACCIDENT OCTOBER 13, 1966 LATE EVENING INITIAL EVENT STYRENE VAPOR COMBUSTION
5POLYMERIZATION REACTORS IN THE BUILDING2 REACTORS WERE USED FOR THE PROCESS DESCRIBED BELOW
PHYSICAL PROPERTIES OF STYRENE·MOLECULAR WEIGHT 104.5·BOILING POINT 145C·FREEZING POINT -30.6C·FLASH POINT 31C·AUTOIGNITION TEMPERATURE 490C CH=CH 2
ADDITIONAL PROPERTIES OF STYRENEFLAMMABLE LIMITS IN AIR (VOL%) 1.1 TO 6.1OSHA PEL 50 PPMWILL POLYMERIZE AT ROOM TEMPERATURE IF UNINHIBITEDHEAT OF POLYMERIZATION 74.5 MJ/KMOLCP, HEAT CAPACITY 1.69 J/G
ARRHENIUS EQUATIONk Rate constantA Pre-exponential constantEa Activation energyR Gas ConstantT Absolute temperature
EQUATIONS TO PREDICT TIME, Dt, TO RUNAWAYa is a proportionality constantT1 is the initial temperature
ADIABATIC TEMPERATURE RISE OF CATALYZED STYRENE (HYPOTHETICAL EXAMPLE) from Boyle 100 o C, 10 MIN TO RUNAWAY At ~130 t, MINUTES 10 D 1 TIME, 0.1 100 150 200 o BATCH TEMPERATURE, C
STYRENE POLYMERIZATION METHODSANIONIC POLYMERIZATIONCATIONIC POLYMERIZATIONFREE RADICAL POLYMERIZATIONZIEGLER NATTA POLYMERIZATION
FREE RADICAL POLYMERIZATION INITIATION . . CH=CH CH-CH R CH-CH R 2 + R . 2 2 . PROPAGATION R . n + D
STYRENE TO POLYSTYRENE BATCH PROCESS1. LOAD THE REACTOR WITH STYRENE2. ADD POLYMERIZATION CATALYST3. HEAT TO 95°C4. HOLD FOR 2 TO 8 HOURS
STYRENE TO POLYSTYRENE BATCH PROCESS CONTINUED5. TRANSFER TO FORMING UNIT AT ABOUT 75% CONVERSION6. OPEN FORMING UNIT AFTER FULL CONVERSION. REMOVE PS BLOCK7. CRUSH PS BLOCK8. TRANSFER SOLIDS TO EXTRUDER
THE RELIEF SYSTEM TO ROOF OUTSIDE BUILDING SIGHT GLASS RUPTURE DISC REACTOR INSIDE BUILDING
TIME LINE EARLY IN THE DAY OF EXPLOSIONTIME NOTE2:30 POLYMER A PRODUCED19:30 STARTED POLYMER B BATCH19:30 LOADED MATERIAL19:40 STARTED HEATING21:15 HEATED TO 92°C
TIME LINE BEFORE EXPLOSIONTIME TEMP,C NOTE21:15 92 21:45 110 R.O. (REACTOR OPER.) IN CANTEEN21:51 115 21:55 119 22:00 126 R.O. RETURNED FROM CANTEEN
TIME LINE MINUTES BEFORE EXPLOSIONTIME TEMP,C NOTE22:02 130 R.O. CHECKS IN22:03 132 R.O. ORDERS DUMP22:04 137 3 MEN ATTEMPT DUMP22:07 170 R.O. ORDERS 3 BOLTS ON FLANGE22:08 R.O. ORDERS EVACUATION
INVESTIGATIONCOMPARISON/CONTRAST OF TWO REACTORS ITEM REACTOR 1 REACTOR 2 (THE OTHER) (THE SUSPECT) RUPTURE DISC INTACT RUPTURED MANWAY INTACT INTACTDUMP VALVE CLOSED 1/4 OPENSIGHT GLASS INTACT MISSINGANSWER: FAILED SIGHT GLASS
Courtesy Prof. Chuck Sheppard, Univ. of Tulsa
EXTENT OF EXPLOSION11 PEOPLE KILLED130 TON CAR OF VINYL CHLORIDE TIPPED OVERGUARDHOUSE DESTROYEDBRICKS FOUND 400 FEET AWAY
TNT EQUIVALENTBASED ON THE ESTIMATED OVERPRESSURES AND AMOUNT OF STYRENE RELEASED BEFORE THE INITIAL COMBUSTIONTHE COMBUSTION WAS AS IF 6.6 TONS OF TNTEXPLODED AT ONCE
FIRE PROTECTION SYSTEMSSPRINKLER SYSTEMSFIRE WATER PUMPSFIRE RATED WALLS AND BARRIERS
BROKEN SPRINKLER MAIN REMAINS OF POLYMERIZATION BUILDING
PROPERTY DAMAGE SUMMARYPOLYSTYRENE BUILDING DESTROYEDBUILDINGS 1,4,5,8,&12 SUFFERED FIRE AND WATER DAMAGEPUMP HOUSE DESTROYEDSEVERAL AUTOMOBILES DAMAGED
INVESTIGATIONSEARCH FOR THE ROOT CAUSEPRINCIPAL CAUSE – RUNAWAY REACTION CAUSED A PRESSURE BUILDUP INSIDE A REACTOR THAT SUBSEQUENTLY RELIEVED.ALL MATERIAL RELIEVED SHOULD HAVE EXITED BUILDING THROUGH ROOF VENT.