1. 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

2. ST. LAWRENCE RIVER
PROVINCE OF QUEBEC
CANADA
ISLE OF MONTREAL
LACHINE
CANAL
LASALLE

7. STYRENE VAPOR COMBUSTION
THE ACCIDENT
OCTOBER 13, 1966
LATE EVENING
INITIAL EVENT
STYRENE VAPOR COMBUSTION

17. BACKGROUND

19. 5 POLYMERIZATION REACTORS IN THE BUILDING 2 REACTORS WERE USED FOR THE PROCESS DESCRIBED BELOW

20. PHYSICAL PROPERTIES OF STYRENE · MOLECULAR WEIGHT. 104
PHYSICAL PROPERTIES OF STYRENE ·     MOLECULAR WEIGHT ·       BOILING POINT 145C ·       FREEZING POINT -30.6C ·       FLASH POINT 31C ·       AUTOIGNITION TEMPERATURE C
CH=CH 2

21. ADDITIONAL PROPERTIES OF STYRENE FLAMMABLE LIMITS IN AIR (VOL%). 1
ADDITIONAL PROPERTIES OF STYRENE FLAMMABLE LIMITS IN AIR (VOL%) 1.1 TO 6.1 OSHA PEL 50 PPM WILL POLYMERIZE AT ROOM TEMPERATURE IF UNINHIBITED HEAT OF POLYMERIZATION 74.5 MJ/KMOL CP, HEAT CAPACITY 1.69 J/G

23. ARRHENIUS EQUATION k. Rate constant A. Pre-exponential constant Ea
ARRHENIUS EQUATION k Rate constant A Pre-exponential constant Ea Activation energy R Gas Constant T Absolute temperature

25. EQUATIONS TO PREDICT TIME, Dt, TO RUNAWAY   a is a proportionality constant T1 is the initial temperature

26. D ADIABATIC TEMPERATURE RISE OF CATALYZED
STYRENE (HYPOTHETICAL EXAMPLE) from Boyle
100 o
At ~130
C, 10 MIN TO RUNAWAY
t, MINUTES 10 D 1
TIME,
0.1
100
150
200 o
BATCH TEMPERATURE, C

27. STYRENE POLYMERIZATION METHODS ANIONIC POLYMERIZATION CATIONIC POLYMERIZATION FREE RADICAL POLYMERIZATION ZIEGLER NATTA POLYMERIZATION

28. . FREE RADICAL POLYMERIZATION CH=CH CH-CH R R INITIATION + R .2
+ R .
CH-CH R .
INITIATION
PROPAGATION R n
+ D

29. STYRENE TO POLYSTYRENE BATCH PROCESS 1. LOAD THE REACTOR WITH STYRENE 2. ADD POLYMERIZATION CATALYST 3. HEAT TO 95°C 4. HOLD FOR 2 TO 8 HOURS

30. STYRENE TO POLYSTYRENE BATCH PROCESS CONTINUED 5
STYRENE TO POLYSTYRENE BATCH PROCESS CONTINUED 5. TRANSFER TO FORMING UNIT AT ABOUT 75% CONVERSION 6. OPEN FORMING UNIT AFTER FULL CONVERSION. REMOVE PS BLOCK 7. CRUSH PS BLOCK 8. TRANSFER SOLIDS TO EXTRUDER

34. THE RELIEF SYSTEM TO ROOF SIGHT GLASS RUPTURE DISC
OUTSIDE
BUILDING
SIGHT
GLASS
RUPTURE
DISC
REACTOR
INSIDE BUILDING

35. TIME LINE EARLY IN THE DAY OF EXPLOSION TIME. NOTE 2:30
TIME LINE EARLY IN THE DAY OF EXPLOSION TIME NOTE 2:30 POLYMER A PRODUCED 19:30 STARTED POLYMER B BATCH 19:30 LOADED MATERIAL 19:40 STARTED HEATING 21:15 HEATED TO 92°C

36. TIME LINE BEFORE EXPLOSION TIME. TEMP,C. NOTE 21:15. 92. 21:45. 110. R
TIME LINE BEFORE EXPLOSION TIME TEMP,C NOTE 21: : R.O. (REACTOR OPER.) IN CANTEEN 21: : : R.O. RETURNED FROM CANTEEN

37. TIME LINE MINUTES BEFORE EXPLOSION TIME. TEMP,C. NOTE 22:02. 130 R. O
TIME LINE MINUTES BEFORE EXPLOSION TIME TEMP,C NOTE 22: R.O. CHECKS IN 22: R.O. ORDERS DUMP 22: MEN ATTEMPT DUMP 22: R.O. ORDERS 3 BOLTS ON FLANGE 22: R.O. ORDERS EVACUATION

39. ?? HOW DID STYRENE FOG ENTER THE INTERNAL BUILDING ??

40. INVESTIGATION COMPARISON/CONTRAST OF TWO REACTORS
ITEM REACTOR 1 REACTOR 2
(THE OTHER) (THE SUSPECT)
RUPTURE DISC INTACT RUPTURED MANWAY INTACT INTACT DUMP VALVE CLOSED 1/4 OPEN SIGHT GLASS INTACT MISSING ANSWER: FAILED SIGHT GLASS

41. Courtesy
Prof. Chuck Sheppard,
Univ. of Tulsa

42. A CONFINED SPACE EXPLOSION

43. EXTENT OF EXPLOSION 11 PEOPLE KILLED 130 TON CAR OF VINYL CHLORIDE TIPPED OVER GUARDHOUSE DESTROYED BRICKS FOUND 400 FEET AWAY

44. TNT EQUIVALENT BASED ON THE ESTIMATED OVERPRESSURES AND AMOUNT OF STYRENE RELEASED BEFORE THE INITIAL COMBUSTION THE COMBUSTION WAS AS IF 6.6 TONS OF TNT EXPLODED AT ONCE

46. FIRE PROTECTION SYSTEMS SPRINKLER SYSTEMS FIRE WATER PUMPS FIRE RATED WALLS AND BARRIERS

47. BROKEN SPRINKLER MAIN
REMAINS OF POLYMERIZATION BUILDING

49. PROPERTY DAMAGE SUMMARY POLYSTYRENE BUILDING DESTROYED BUILDINGS 1,4,5,8,&12 SUFFERED FIRE AND WATER DAMAGE PUMP HOUSE DESTROYED SEVERAL AUTOMOBILES DAMAGED

50. INVESTIGATION SEARCH FOR THE ROOT CAUSE PRINCIPAL CAUSE – RUNAWAY REACTION CAUSED A PRESSURE BUILDUP INSIDE A REACTOR THAT SUBSEQUENTLY RELIEVED. ALL MATERIAL RELIEVED SHOULD HAVE EXITED BUILDING THROUGH ROOF VENT.

51. TESTIMONY STYRENE VAPOR INSIDE PS BUILDING WHY
TESTIMONY STYRENE VAPOR INSIDE PS BUILDING WHY? FAILED SIGHT GLASS ABOVE RUPTURE DISK

52. POSSIBLE IGNITION SOURCE ARCING MOTOR. HOT SURFACES
POSSIBLE IGNITION SOURCE ARCING MOTOR? HOT SURFACES? ELECTROSTATIC DISCHARGE?

53. WHY DID THE REACTION RUN AWAY. WRONG CAM ON THE RECORDER
WHY DID THE REACTION RUN AWAY? WRONG CAM ON THE RECORDER? OR THE PENS STUCK?

54. LESSONS LEARNED MAINTAIN CRITICAL PROCESS EQUIPMENT INSTALL AUDIBLE ALARMS CENTRALIZE CONTROL OF BATCH OPERATIONS ELIMINATE SIGHT GLASS VIEWPORTS FROM RELIEF LINES HAVE SEMI-AUTOMATED DISCHARGE SYSTEMS (REMOTE DUMP VALVE)

55. BROADER LESSONS LEARNED USE DOW FIRE AND EXPLOSION INDEX FOR SPACING OF PROCESS EQUIPMENT STORAGE TANKS, AND TANK CAR KEEP UPDATED DISASTER CONTROL PLANS

56. OTHER LESSONS LEARNED REDUNDANT PROCESS CONTROL EQUIPMENT LOCATION OF EMERGENCY POWER AND FIRE PROTECTION FAIL SAFE VALVES ON STORAGE TANKS

57. ACKNOWLEDGEMENT DR. WALT HOWARD LASALLE FIRE DEPARTMENT MR
ACKNOWLEDGEMENT DR. WALT HOWARD LASALLE FIRE DEPARTMENT MR. ROBERT GUERARD MR. JOHN PAUL LACOURSIERE SACHE COMMITTEE