Ethanol Tank Fire Fighting

Transcription

1 Ethanol Tank Fire Fighting Background and previous research

2 Why do we need ETANKFIRE? Handling and storage volumes of ethanol are increasing Ensure adequate investments in ethanol fire protection Different properties compared to petroleum products Lack of specific fire protection recommendations Limited practical experience of ethanol tank fires

3 What are the important differences? Important differences compared to petroleum products, e.g. gasoline Flammability Burning behaviour Extinguishment

4 Parameters defining risk for fire and explosion Flash point The lowest temperature where the product could be ignited Classification system (1, 2a, 2b, 3)

5 Probability for ignition- Open spill Flash point Gasoline <-40C Ethanol + 12C E85 approx -30C up to -18C (varying winter/summer) E95 (denaturized etanol) (about -5C) Fuel vapour density Gasoline 3,5 x air Ethanol ca 1,6 x air (E85?) Conductivity (ps/m) Gasoline >50 Ethanol Conclusion: Ethanol could be judged to have a lower/similar probability for ignition compared to gasoline

6 Flammability - Closed vessel Fuel vapours/air Flammable?

7 Flammability - Closed vessel Lower Flammability Limit-LFL( C) Flammable conditions Upper Flammability Limit-UFL( C) Ethanol 12-40C (54-104F) Lean Flammable Rich mixture mixture mixture Temperature

8 Rich vapour concentration-flame only in opening

9 Flammable vapour concentration flame penetrates into vessel

10 Increased risk for tank explosion

11 Increased risk for tank explosion

12 Fuel vapour concentration in a storage tank with internal floater Normally too lean mixture Could be flammable during filling or discharge

13 Effect of heat exposure Critical area Flames Heat radiation Lean fuel mixture that might transfer to flammable conditions Voids below internal floater Gasoline-Rich Ethanol-flammable?? Auto ignition temperature?

14 Tank explosion, Sweden- dec 2009

15 Fire escalation in tank storage Picture from Industrial Fire World, March-April 2008

16 r Celsius) Temperat tur (grade Flammable vapours in enclosures Ref: SP report 2008:39 NREL/TP Temperaturområde i vilket brännbar luft/bränsleblandning förekommer i slutna behållare för olika bränslen. Bensin Gasoline Ethanol Etanol E95 E85 Summer sommar Winter vinter 1 1,5 2 2,5 3 ºF Auto ignition temperature: Gasoline C ( F) Ethanol ca C ( F)

17 Probability for ignition in an enclosure Conclusions: Vapours from pure ethanol are flammable at normal temperatures while gasoline produces vapours that are too fuel rich in air in most situations Tanks for ethanol should be equiped with flame arrestors on pressure release equipment Thermal exposure can rapidly heat the tank wall to the auto ignition temperature of ethanol Addition of gasoline has a positive effect as the probability bilit that t vapour mixtures are fuel rich is increased

18 Burning behaviour, 1,7 m 2 E85 Gasoline

19 Heat radiation (kw/m 2 ) at 3 m distance 12 Värmestrålning 3 m avstånd från bålkant P Gasoline C22 bensin C22 E85 kw/ m2 6 4 E Tid [min]

20 Increased heat radiation compared to Gasoline

21 Heat radiation from Gasoline and Acetone/Ethanol Colour scale: Gasoline Acetone/ethanol

22 Heat radiation from Gasoline and Acetone/Ethanol Radiation (kw/m 2 ) Distance (m)

23 Heat radiation calculations-ethanol (Gasoline) Flame height ht 43,2 m (25,6) 12,5 kw/m 2 at 30 m (15) Shell PIPA 3.0

24 Needs to improve heat radiation models Large scale tests to provide data regarding: g Heat radiation vs distance Flame emissivity i it Flame length Burning rate Influence of various ethanol/gasoline mixtures

25 Fire extinguishment tests on water miscible fuels Metanol och M15 50 >> 0,25 m 2 (1980) Aceton/etanol 200 m 2 (1990) Gasoline plus 0-10% ethanol 0,6 m 2 (2003) LASTFIRE 4,5 m 2 (2010) EERC- E10 and E95 4,5 m 2 (2007)

26 Methanol and M15 (1980) L of fuel (200 mm) About 80 extinguishing tests: 0,25 m 2, 0,6 m 2, 4 m 2, 11 m 2, 50 m 2 Heat radiation and burning rate

27 50 m 2 Methanol AFFF-AR-foam

28 50 m 2 Methanol FP-AR-foam

29 Fire tests on Gasoline and Acetone/Ethanol (1990) Pool area: about 200 m 2 Fuel: l ( mm) Preburn time: 6 min Application rate: max 10 l/m 2 min (2000 l/min) Application method: Bouncing (and attempt to backboard) Measurements: Heat radiation, time to 90% control, extinguishment, burnback, total foam consumption, etc.

30 200 m 2 Acetone/Ethanol - AFFF-AR, Backboard

31 200 m 2 Acetone/Ethanol - AFFF-AR, Bounce

32 Lastfire ethanol tests S f L tfi t t k Summary of Lastfire test work on ethanol presented by Niall R

33 GOAL Assemble a scientifically based body of knowledge regarding effective fire and spill control methods Develop educational materials, training programs and other products for emergency responders TESTING In February 2007, various foam agents were tested against ethanol fuel fires AR-AFFF was the only foam agent that successfully passed all tests against E10 and E85/95 EERC@iafc.org

34 Application Types (Foams) Type II Type III Sprinklers Foam E-10 E-95 E-10 E-95 E E-95 Class A Emulsifiers AR-FFFP YES* Fluro Protein YES AFFF YES AR-AFFFAFFF YES YES YES YES** YES** YES* = Higher application rate was required for extinguishment YES = Higher application rate was required for extinguishment Did not pass burn back test Failed UL-162 Test YES** = Only the AR-AFFF was capable of passing Sprinkler Test with non-aspirating heads

35 Comments to the EERC work EERC is a good example of bringing resources together to solve a specific problem Comprehensive training program available at internet Training seminars held around in US Focused on transport fire scenarios (spill fires) The tank fire protection recommendations are based on common practice for petroleum products Adding the results from ETANKFIRE to the EERC work would cover the full range of fire protection problems related to ethanol

36 Limitations of standard tests for foams (ISO 7203, EN 1568, UL 162, IMO 1312, Lastfire,..) Represent spill fires Thin fuel layers mm Preburn time 1-3 minutes Indirect application (back-board) Extinguishment 3-7 min Dilution effect about 30%

37 Fuel dilution must be considered when evaluating test data! EN 1568 with E95, backboard vs direct application Appl method Ext (min:s) #3 AFFF-AR BB 0:49 #4 AFFF-AR AR Direct 4:50 2 x appl rate #6 RF3x6ATC BB 0:51 #5 RF3x6ATC Direct 5:07 2 x appl rate Ref: No escaping the trends, Industrial Fire Journal-April 2008

38 Fuel dilution must be considered when evaluating test data! EN 1568 with E95, backboard vs direct application Appl Ext Dilution method (min:s) (%) #3 AFFF-AR BB 0:49 15 #4 AFFF-AR AR Direct 4: x appl rate #6 RF3x6ATC BB 0:51 15 #5 RF3x6ATC Direct 5: x appl rate Ref: No escaping the trends, Industrial Fire Journal-April 2008

39 What about tank fires?

40 Experience from real fires 480 tank fires identified Almost all extinguished by foam monitors. No reports on foam pourer system SP Report 2004:14 Only 8 tank fires with water miscible fuels

41 Conditions for tank fire fighting Large diameters (long foam run) Large fuel depth ( no dilution effect) Long preburn time (heated fuel, hot steel surfaces) Bounce/backboard application not possible

42 Experience from real fires Date Company/location Fuel Foam tot (l) Foam (l/m 2 ) GATX, CA Chemicals no info Herne, Ger. IPA , Tampa, FL, IPA no info Coode Island Chemicals ( ) Rio d Janerio Alcohol no info Tampa, FL Methanol no info -

43 Experience from real fires (cont.) Date Company/location Fuel Foam tot (l) Foam (l/m2 ) Amoco MTBE *) ( tank) 65, Nedalco Ethanol Port Kembla Ethanol , Villette-sur-Aube Ethanol Lillers (bund+tank) Ethanol *) Solubility 5% MTBE in water, 1.5% water in MTBE

44 Port Kembla - Ethanol tank fire Photo: Fire & Rescue NSW 32 m in diameter, about 4000 m 3 ethanol Explosion blow off the roof Very hot fire

45 Port Kembla experience Photo: Fire & Rescue NSW

46 Port Kembla experience Photo: Fire & Rescue NSW

47 Port Kembla experience Photo: Fire & Rescue NSW Extinguished after about 25 hours (burn-out) Diluted to about 10% ethanol About l of AFFF-AR

48 Villette-sur-Aube and Lillers

49 Conclusions-Ethanol fire fighting There are two central requirements High quality AR-foam Gentle application Foam consumption from standard tests compares reasonably well to spill fires if gentle application is used, but not to tank fires. Experience of successful tank fire extinguishment in ethanol is lacking (so far only controlled burn out reported - extinguished by dilution) Foam monitor (Type III) application is not likely to be successful, even at increased application rates