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DESIGN STRATEGIES WITH RESPECT TO HAZARDOUS MATERIALS

DESIGN STRATEGIES WITH RESPECT TO HAZARDOUS MATERIALS. THE NATURE OF RISK IN INDUSTRIAL FACILITIES. http://www.bls.gov/iif/oshwc/cfoi/cfch0008.pdf. FATAL WORK INJURIES. http://www.bls.gov/iif/oshwc/cfoi/cfch0008.pdf. FATAL WORK INJURIES. http://www.bls.gov/iif/oshwc/cfoi/cfch0008.pdf.

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DESIGN STRATEGIES WITH RESPECT TO HAZARDOUS MATERIALS

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  1. DESIGN STRATEGIES WITH RESPECT TO HAZARDOUS MATERIALS

  2. THE NATURE OF RISK IN INDUSTRIALFACILITIES http://www.bls.gov/iif/oshwc/cfoi/cfch0008.pdf

  3. FATAL WORK INJURIES http://www.bls.gov/iif/oshwc/cfoi/cfch0008.pdf

  4. FATAL WORK INJURIES http://www.bls.gov/iif/oshwc/cfoi/cfch0008.pdf

  5. THE NATURE OF RISK IN INDUSTRIAL FACILITIES • COMPARISON VALUES - DEATHS/100,000 WORKERS • IN 1912, 21 (18,000 - 21,000 DEATHS) • IN 1992, 4.2 (TRIPLE THE NUMBER OF WORKERS)

  6. SUMMARY OF MAJOR INCIDENTS2,3 • FLIXBOROUGH, ENGLAND (1974) - CYCLOHEXANE MANUFACTURING AS A NYLON PRECURSOR 4,5 • VAPOR CLOUD EXPLOSION • KILLED 28 PEOPLE • CAUSE APPEARED TO BE DESIGN FOR TEMPORARY PIPING SYSTEM

  7. FLIXBOROUGH

  8. SUMMARY OF MAJOR INCIDENTS • SEVESO, ITALY (1976) - DIOXIN6 • TCP (2,4,5-TRICHLOROPHENOL) REACTOR EXPLODED RELEASING TCDD, (2,3,7,8-TETRACHLORODIBENZO-p-DIOXIN • THIS MATERIAL WAS A COMPONENT IN AGENT ORANGE

  9. SUMMARY OF MAJOR INCIDENTS • SEVESO, ITALY (1976) - DIOXIN6 • PLUME SPREAD OVER AN AREA THAT CONTAINED OVER 100,000 PERSONS AND IMPACTED OTHER MUNICIPALITIES WITH A POPULATION OF 17000 • PRIMARY IMPACT WAS FEAR OF LONG-TERM EFFECTS AND OVERCOMING INITIAL TRAUMA • COULD BE THE SOURCE OF SARA TITLE III REQUIREMENTS

  10. SUMMARY OF MAJOR INCIDENTS • MEXICO CITY, MEXICO (1984) - LPG (LIQUID PETROLEUM GAS) TERMINAL • A BLEVE (BOILING LIQUID EXPANDING VAPOUR EXPLOSION) 7 • 650 DEATHS • 6400 INJURIES • PLANT DAMAGE = $31.3 MILLION

  11. SUMMARY OF MAJOR INCIDENTS • BHOPAL, INDIA (1984) - PESTICIDE MANUFACTURING8 • UNEXPECTED CHEMICAL REACTION WHEN WATER ENTERED AN MIC (METHYL ISOCYANATE) STORAGE TANK • RELEASED ABOUT 40 TONS OF MATERIAL OVER A 2 HOUR PERIOD • SPREAD OVER A LOCAL POPULATION OF ABOUT 900,000 • ESTIMATED 3800 DEAD AND 11,000 DISABLED

  12. SUMMARY OF MAJOR INCIDENTS • BHOPAL, INDIA (1984) - PESTICIDE MANUFACTURING8 • TRACED TO A NUMBER OF POSSIBLE SOURCES9 • FAILURE TO MAINTAIN SAFETY SYSTEMS • INADEQUATE DESIGN OF SAFETY SYSTEMS • MIS-OPERATION OF THE FACILITY

  13. SUMMARY OF MAJOR INCIDENTS • PASADENA, TEXAS (1989) - POLYETHYLENE MANUFACTURING • POLYETHYLENE REACTOR EXPLOSION • KILLED 23 PEOPLE AND INJURED 130 • TRACED TO EITHER A SEAL FAILURE ON THE REACTOR AND/OR USE OF INEXPERIENCED MAINTENANCE PERSONNEL

  14. EXAMPLE OF INCIDENT • BHOPAL RELEASE • HOW IT OCCURRED • HOW IT WAS ANALYZED • RESULTING CHANGES

  15. FUNDAMENTALS OF PROCESSES • THERMODYNAMICS • CONSERVATION OF MASS AND ENERGY • MASS IS NEITHER CREATED OR DESTROYED • ENERGY IS NEITHER CREATED OR DESTROYED

  16. FUNDAMENTALS OF PROCESSES • THERMODYNAMICS • PROCESSES REQUIRE CHANGING CONDITIONSSYSTEMS MOVE TOWARDS A NEW EQUILIBRIUM • THE RATE DEPENDS ON THE CHEMICAL AND MECHANICAL PROPERTIES OF THE SYSTEM • WATER DOES NOT FLOW UPHILL WITHOUT A BOOST

  17. FUNDAMENTALS OF PROCESSES • EXAMPLE OF ETHANOL DISTILLATION

  18. FUNDAMENTALS OF PROCESSES • ENERGY/MATERIAL QUALITY CHANGES • ENERGY • MAY BE ADDED OR REMOVED TO INITIATE A SYSTEM CHANGE • WHEN ENERGY IS ADDED, IT FLOWS THROUGH THE SYSTEM TO BE CONSERVED, BUT IT IS DEGRADED IN QUALITY

  19. ENERGY QUALITY CHANGES • EXAMPLE OF HYDROELECTRIC POWER PLANT

  20. ENERGY QUALITY CHANGES • EXAMPLE OF HYDROELECTRIC POWER • WATER CHANGES ITS EQUILIBRIUM POSITION WITH A RESULTANT CHANGE IN POTENTIAL ENERGY AND POWER PRODUCTION • WATER IN THE RIVER CANNOT BE USED TO DRIVE THE TURBINE BECAUSE IT IS AT A LOWER POTENTIAL ENERGY LEVEL

  21. MATERIAL QUALITY CHANGES • PURE CHEMICALS THAT ARE DISPERSED IN WATER (SOLUBLE IN WATER) CANNOT BE RETURNED TO THEIR ORIGINAL PURITY WITHOUT USING ENERGY • DISTILLATION - ENERGY TO VAPORIZE/CONDENSE • CRYSTALLIZATION - ENERGY TO FREEZE/MELT • ADSORPTION OR ADSORPTION -ENERGY TO REGENERATE

  22. REACTIONS • RESULTS IN FORMATION OF NEW CHEMICAL SPECIES • ELEMENTS ARE CONSERVED, BUT NEW MOLECULES MAY BE FORMED • REACTIONS CAN BE SINGLE, IN PARALLEL OR IN SERIES • MOLAR RELATIONSHIPS EXIST BETWEEN REACTANTS AND PRODUCTS

  23. REACTIONS • EXAMPLE OF METHANE COMBUSTION: • STOCHIOMETRIC REACTION

  24. REACTIONS • STOCHIOMETRIC REACTION WITH AIR FOR THE OXIDANT

  25. REACTIONS • REAL REACTIONS MAY NOT GO TO COMPLETION • MAY REQUIRE AN EXCESS OF ONE COMPONENT TO COMPLETELY REACT THE OTHER

  26. REACTIONS • METHANE COMBUSTION WITH 130% EXCESS AIR

  27. REACTIONS • PARALLEL ETHANE COMBUSTION REACTIONS WITH 200% EXCESS AIR AND INCOMPLETE COMBUSTION

  28. REACTIONS • MOST REACTIONS DO NOT GO TO COMPLETION • COMBUSTION CAN HAVE PRIMARY PRODUCTS OF CO2, H2O AND N2 • BYPRODUCTS CAN INCLUDE CO, UNBURNED HYDROCARBONS, NOx, AND SO2 IN SMALLER QUANTITIES

  29. REACTIONS • OTHER TYPES OF OXIDATION-REDUCTION REACTIONS

  30. REACTIONS • OTHER TYPES OF NON-REDOX REACTIONS:

  31. SEPARATION PROCESSES • PROCESSES TO SEPARATE COMPONENTS, BEFORE OR AFTER REACTIONS • PROCESSES TO CONCENTRATE COMPONENTS • THE DRIVING FORCES FOR MOST OF THESE PROCESSES ARE • CHEMICAL EQUILIBRIUM • MECHANICAL • RATE DEPENDENT

  32. SEPARATION PROCESSES • PROCESS EFFICIENCY IS RELATED TO THE DEVIATION REQUIRED FROM AMBIENT CONDITIONS • THE MORE CHANGE REQUIRED, THE LESS THE EFFICIENCY • THE LESS CHANGE REQUIRED, THE HIGHER THE EFFICIENCY • ALL HAVE POTENTIAL HAZARDS ASSOCIATED WITH THEM

  33. TRANSPORT PROCESSES • USED TO MOVE MATERIAL BETWEEN PROCESS OPERATIONS • PUMPS • TURBINES • CONVEYORS • GRAVITY • PNEUMATIC

  34. STORAGE OPERATIONS • RAW MATERIALS • FINISHED GOODS • INTERMEDIATES • OFF-SPEC MATERIALS

  35. CONTROL SYSTEMS • PROCESSES FOR NORMAL OPERATION • CONTINUOUS OPERATIONS • BATCH OPERATIONS • START-UP

  36. CONTROL SYSTEMS • PROCESSES FOR NORMAL OPERATION • CONTINUOUS OPERATIONS • BATCH OPERATIONS • START-UP • SHUTDOWN • PROCESS INTERRUPTION • ROUTINE SHUTDOWN • EMERGENCY SHUTDOWN

  37. CONTROL SYSTEMS • SAFETY SYSTEMS • OUT-OF-RANGE CONDITIONS • INTERLOCKS BETWEEN UNITS

  38. INHERENTLY SAFE DESIGN10,11 • TECHNIQUES THAT REDUCE THE RISKS ASSOCIATED WITH OPERATIONS • EQUIPMENT FAILURE SHOULD NOT SERIOUSLY AFFECT SAFETY, OUTPUT OR EFFICIENCY

  39. MINIMIZATION OF THE INTENSITY • REDUCE QUANTITIES OF MATERIALS MAINTAINED IN INVENTORIES AND IN THE PROCESS • QUANTITIES IN INVENTORIES • REDUCED CAPITAL COSTS • REDUCED MAINTENANCE • LESS MATERIAL TO PARTICIPATE IN A REACTION • HAZARDOUS REACTANT BE MANUFACTURED ON SITE FROM LESS HAZARDOUS PRECURSORS

  40. REACTORS • SMALLER REACTORS TYPICALLY HAVE LESS MATERIAL IN PROCESS • HAVE BETTER CONTROL OF HEAT TRANSFER • AND CAN BE MORE EFFICIENT12

  41. GENERAL FACTORS TO REDUCE REACTOR RISKS13

  42. GENERAL FACTORS TO REDUCE REACTOR RISKS13

  43. COMPARISON OF REACTOR ALTERNATIVES

  44. COMPARISON OF REACTOR ALTERNATIVES • CONTINUOUS REACTORS HAVE SMALLER INVENTORIES THAN BATCH REACTORS • TUBULAR REACTORS HAVE SMALLER INVENTORIES THAN TANK REACTORS • THIN FILM REACTORS HAVE SMALLER INVENTORIES THAN TUBULAR REACTORS • GAS PHASE REACTORS HAVE LESS INVENTORY THAN LIQUID PHASE REACTOR

  45. SUBSTITUTION • USE OF SAFER NON-REACTIVE CHEMICALS • MAY DECREASE EFFICIENCY • MAY ALSO DECREASE COSTS

  46. SUBSTITUTION • HEAT TRANSFER • FOR HIGH TEMPERATURE HEAT TRANSFER USE WATER OR MOLTEN SALTS IN PLACE OF HYDROCARBON-BASED HEAT TRANSFER FLUIDS14,15

  47. SUBSTITUTION • HEAT TRANSFER • FOR LOW TEMPERATURE HEAT TRANSFER REPLACE OZONE SCAVENGING FLUIDS (FREONS) WITH ALTERNATES (N2, PROPANE, HYDROFLUOROCARBONS)16

  48. SUBSTITUTION • SOLVENT REPLACEMENT • USE WATER-BASED PAINT IN PLACE OF SOLVENT-BASED PAINTS • USE OF WATER-BASED SOLVENTS OR CO2 IN CHIP MANUFACTURING PROCESSES17,18 (OFTEN WITH IMPROVED PRODUCT PERFORMANCE)

  49. ATTENUATION • MODIFY CONDITIONS TO MINIMIZE THE IMPACT OF HAZARDOUS EVENTS19 • ADDITION OF INERT COMPONENT TO SYSTEM CAN DILUTE THE POSSIBLE INTENSITY OF A REACTION • MODIFIED CATALYSTS CAN REDUCE THE TEMPERATURES AND PRESSURES REQUIRED FOR THE REACTION20

  50. ATTENUATION • STORAGE OPTIONS • LIQUIFIED GASES STORED AT CRYOGENIC TEMPERATURES • STORED AT ATMOSPHERIC PRESSURE • USES SMALLER VOLUMES THAT GAS STORAGE • TEMPERATURES ARE FREQUENTLY BELOW IGNITION TEMPERATURES IN AIR

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