Hydrogen Safety Hydrogen Safety Training ProgramTraining Program

Presented by:

BOC Gases

NATIONAL TRAINING CENTER

Hydrogen...Hydrogen...What Do You Know What Do You Know

About It?About It?

Is it the Bad Boy of the Gas World?Is it the Bad Boy of the Gas World?

HYDROGEN BOMB

HINDENBURG

THE FIRE

The passengers and crew had only seconds to react. Some jumped out of the windows, some fell. Since the Hindenburg was still 300 feet (roughly equal to 30 stories) in the air when it caught fire, many of these passengers did not survive the fall. Other passengers got wedged inside the ship by moving furniture and fallen passengers. Other passengers and crew jumped from the ship once it neared the ground. Even others were rescued from the burning bulk after it had hit the ground.

Considering the quickness of the catastrophe, it is amazing that only 35 of the 97 men and women on board, plus one member of the ground crew, died in the Hindenburg disaster.

Though it was assumed at the time that the fire was caused by a hydrogen gas leak ignited by a spark of static electricity, the cause of the disaster is still controversial.

Fabric, Not Filling, to BlameHydrogen Exonerated in Hindenburg Disaster

SPACE SHUTTLE CHALLENGER

O RING FAILURE

Hydrogen...Hydrogen...

The Fuel of the FutureThe Fuel of the Future

HYDROGEN FACTS

Chemical Symbol : H2

CAS Registry Number : 1333-74-0DOT Classification : Flammable GasDOT Label : Flammable GasTransport Canada Classification : 2.1UN Number : UN 1049 ( compressed gas )

UN 1966 (refrigerated liquid )

H PHYSICAL PROPERTIESGas at atmospheric temperature and pressureExtremely flammableColorlessOdorlessTasteless

Smallest moleculeLightest specific density (14 times lighter than

air)Non-toxic, simple asphyxiantNon-corrosiveMetallurgical: hydrogen embrittlementNormal boiling point: -423.0 °F

H PHYSICAL PROPERTIES cont.

Cryogenic Burns: Damage can result from exposure to cold gases

Lightest of All Chemical Elements: Most abundant substance in the universe

Our sun is a nuclear reactor in which hydrogen continuously fuses into helium. Fusion process creates heat which warms our earth.

H PHYSICAL PROPERTIES cont.

Hydrogen liquid weight is only 0.5906 LB. per gallon

Gaseous hydrogen is always present where there is liquid hydrogen

Hydrogen gas burns with a pale blue color (almost invisible)

Low temperature of liquid hydrogen can solidify any gas except helium

H PHYSICAL PROPERTIES cont.

Hydrogen liquid has a low densityEvery pound vaporized yields 192 scf of gasA pound of liquid nitrogen yields only 13.8 scf

of gasOn a weight basis, gas yield of hydrogen is

almost 14 times as much as that of nitrogenA gallon of liquid hydrogen requires only

114.71 BTU’s of heat to vaporize it. By contrast a gallon of liquid nitrogen requires 578 BTU’s.

H PHYSICAL PROPERTIES cont.

SPECIFIC HEAT VALUESThe amount of heat required to raise the

temperature of hydrogen gas differs very little from that of nitrogen

To heat 1,000 cu. ft. of hydrogen at constant pressure 1°F requires 17.8 Btu’s

Same temperature change for nitrogen requires 18 Btu’s

DENSITY

Density decreases as temperature increases.

If hydrogen liquid remains in the cryogenic vessel for an extended period of time it will

turn to gas.

HYDROGEN CHEMISTRY An atom of hydrogen has the simplest of structures Hydrogen has a nucleus of one proton with a single

electron orbiting about it Both proton and electron are spinning on their own

axis At room temperature, hydrogen has a normal or

equilibrium composition of 75% in the ortho and 25% in the para form

If hydrogen gas is liquefied and stored, it gradually shifts in composition until it reaches an equilibrium when only 0.21% is ortho and 99.79% is para

The shift in structure from ortho to para creates heat

HYDROGEN LIQUEFACTIONCompressedDriedPurifiedCooledExpandedLiquefied

HOW IS HYDROGEN MANUFACTURED?

Catalytic reforming of hydrocarbons (natural gas is CH4)

Dissociation of ammonia (NH3)

Chlorine and sodium chlorate productionElectrolysis of water (H2O)

BOC GASES MANUFACTURING FACILITY IN MAGOG, QUEBEC, CANADAHydrogen gas at

Magog is a by-product of sodium chlorate production

Magog is a 15 ton per day plant which equals 5.76 mmcf

Magog’s storage capacity is 50.7 million gallons

PRODUCT PURITY Standard grade 99.999% hydrogen

<1.0ppm N2 <1.0ppm O2 <1.0ppm H2O <0.5ppm THC <0.5ppm CO <0.5ppm CO2

VLSI- & ULSI-grade up to 99.99997% For the electronics industry

HYDROGEN USESFuel (oxy-hydrogen flame, NASA)Chemical synthesis (ammonia,

methanol)Petroleum refiningHydrogenation of edible

organic oilsReduction of oxygen (controlled

atmosphere in metalworking furnaces, electronics production, float glass)

HYDROGEN HAZARDSFlammabilityAsphyxiantCold contactPressureExpansion ratios

DON’T ADD WATER

Gas % Gas in Mixture With AirAcetone 2.6 12.8

Benzene 1.4 8.8

Carbon Monoxide 12.5 74.2

Ethanol 3.3 19.0

Ethylene 2.8 28.6

Hydrogen 4.0 74.2

Hydrogen Sulfide 4.3 45.5

Methane 5.0 15.0

Methanol 6.7 36.5

Propylene 2.4 10.3

0 20 40 60 80

EXPOSIVE LIMITS OF COMBUSTIBLE GASES WHEN MIXED WITH AIR

FLAMMABILITY OF HYDROGEN IN AIR

4% Barely burn and even then only upward 5% Fire starts burning sideways 18% Fire will now burn faster than the speed of sound 45% Burning at 4600 mph-including shock wave 74% Barely burn 75% Will not burn-no air

With 4%-75% hydrogen, very little energy is required to ignite hydrogen. The speed of a hydrogen fire is ten feet per second to 4600 mph.

Oxygen and hydrogen mixed-speed approximately 8000 mph. The speed of sound is 1050 feet per second.

H FLAMMABILITY-SAFETY PRECAUTIONS

Precautions: Eliminate ignition sourcesNO SMOKING! NO OPEN FLAMES!Use only non-sparking toolsNo synthetic clothing (nylon, etc.)Electrical equipment-explosion proof,

intrinsically safe or purgedBonding and grounding

HYDROGEN FIRES

Hydrogen Fires:

Shut off hydrogen source and allow fire to burn out

Small fires can be extinguished with carbon dioxide or water spray

HYDROGEN FIRES cont.A hydrogen flame is invisible under many

conditionsHydrogen flames cause little damage from

radiationHydrogen flames can burn in a strong wind and be

stretched out away from its source a number of feet

Any venting should be done carefully to prevent accumulation in pockets which may cause an explosive mixture

HYDROGEN FIRE FIGHTING Shut off the source and allow the fire to burn out Daylight fires can be detected by heat waves or a

broom If the fire is extinguished before all the gas burns

off, watch for pockets which may suddenly re-ignite

Very small fires can be controlled with carbon dioxide and water spray

Larger fires may be controlled with steam and/or nitrogen

HYDROGEN FIRE FIGHTING cont.Tanks containing hydrogen should be cooled

with water if near a fireHydrogen vent stack fires can be extinguished

by shutting off the source and snuffing the fire with nitrogen or helium gas

WATER SHOULD NEVER BE SPRAYED ON OR NEAR A VENT STACK!!!

Make sure nitrogen or steam line is attached securely

FIRE FIGHTING EQUIPMENTA fire extinguisher should be located within

the boundaries of the installationAn adequate water supply, fire extinguisher

(either dry chemical or carbon dioxide) and a fire blanket should be in the proximity of a hydrogen station

It is helpful to keep a straw broom nearby to detect flames during daylight hours

HYDROGEN AS AN ASPHYXIANT

Hydrogen is an asphyxiant. It can displace oxygen, causing an oxygen deficient atmosphere. Symptoms of an oxygen deficient atmosphere could include:HeadacheDizzinessBreathing DifficultyNauseaUnconsciousness

Proper ventilation is a must! Do not be caught in an oxygen deficient atmosphere.

COLD CONTACTLiquid (-423 °F) or gaseous hydrogen can cause tissue

freezing or frostbiteFrozen tissues are painless and appear waxy yellowRemove restrictive clothing and immerse affected part in

warm water (approximately 105°F)Do not rub frozen parts, tissue damage may resultNever use dry heat

COLD CONTACT cont. If the exposure has been massive and general

body temperature is depressed, immerse patient in a warm water bath

Supportive treatment for shock should be provided

Medical assistance should be obtained as soon as possible

If the frozen part thaws before medical attention is obtained, cover with loose, dry, sterile dressing

Alcoholic beverages or smoking are prohibited. Warm drinks and food may be administered

PERSONAL PROTECTIVE CLOTHINGLoose fitting glovesSteel toed shoesHard hatEar protection Cotton or Nomex 3 overalls worn outside of

bootsEye protectionLong sleeves (should not be rolled up while

working )

HIGH PRESSURE HAZARDSLiquid hydrogen storage tank maximum

allowable working pressure (mawp) is 175 psiHydrogen cylinders, storage tubes, and tube

trailers: up to 3000 psiStand clear of pressure relief devicesDo not open pressurized fittings or break

pressurized lines

EXPANSION RATIO OF HYDROGENThe expansion ratio of hydrogen from a liquid

to a gas is 850:1Never trap liquid hydrogen in a systemAlways install pressure relief devices where

liquid could get trapped

SPILLS Small spills of liquid hydrogen disperse quickly Any spill should be considered a potential fire Large spills cause ground freezing, hydrogen will

not vaporize quickly. Evacuate area until spill has dissipated

Use water spray to reduce fog and diffuse vapors Cold hydrogen vapor above a spill or frozen

ground is slightly heavier than air Air moving over a spill may carry hydrogen gas

some distance before it warms enough to rise

SPILLS cont.Clouds of gas can quickly become huge fire

balls with tragic resultsAlways lay out an escape route when there is a

spillNO SMOKING, NO FIRES, AND NO OPEN

FLAMES!!!!!!!Do not touch spillStop leak where it can be done safely without

risk to personnel

EMBRITTLEMENTCold liquid or gaseous hydrogen can cause

materials to become embrittledMaterials not intended or designed for use with

cryogens can become a hazardNever use materials that are not rated for the

temperatures and pressures of hydrogen service

AIR CONDENSATION Surfaces cooled by liquid hydrogen can be cold

enough to cause atmospheric air to condense Air will liquefy at -317°F Because Nitrogen boils off before oxygen, the

result can be an oxygen enriched liquid If this liquid drips onto a combustible surface,

such as asphalt, an explosive mixture could result Make sure that all surfaces that this liquid could

come into contact with is cleaned according to oxygen-cleaned standards

LIQUEFIED AIR

THERMAL STRESS Cryogenic piping must contain sufficient

flexibility to withstand the thermal stress related to the cool down to operating temperature

This can be accomplished with suitable pipe routing or expansion joints

Motion of the pipeline due to pressurization and thermal contraction can be reliably predicted

Temperature fluctuations during cool down are not as easily predicted

Unequal cooling of piping systems can stress pipelines and cause damage or system failure

GENERAL REQUIREMENTSFederal/state/local regulationsNationally recognized standardsSite preparationConcrete padFencing/BumpersUtilities

GENERAL SITE REQUIREMENTSAtmospheric conditionsClearance from exposuresUnderground interferenceOverhead interferenceTrailer accessSpill apronGrounding of all equipment

UTILITIESElectricalPhone WaterLighting

FEDERAL REGS & STANDARDSNFPA 50A, 50B, 86CCGA G-5, G-5.3, G-5.4 29 CFR 1910.103EPABOCAOSHAASMEDOTUFC

REFERENCES AND REGULATIONSUFC: Uniform Fire CodeSFPC: Standard Fire Prevention CodeSBCCI: Southern Building Code

Congress InternationalUBPVL: Uniform Boiler and Pressure

Vessel LawsASME: American Society of Mechanical

Engineers

REFERENCES AND REGULATIONSState and municipal fire and building codesCorporate standards Insurance company standardsBOC Gases standards

Hydrogen Piping SpecificationsHydrogen Safety & Loss Prevention

REFERENCES AND REGS cont.BOC Gases National Training Center Hydrogen

Training ManualBOC Gases Loss Control ManualBOC Gases Oxygen Compatibility Source

ManualBOC Gases Customer Station Inspection

procedure-IES-P-INS-001BOC Site Access Standard IES-S-STE-001

EQUIPMENT FOR H SERVICESuitable for temperatureSuitable for pressureMaterial constructionCleaned for hydrogen serviceCv factor for flow velocitiesLeak ratePumping systems

LABELING AND MARKINGSThe Corporate Identification LogoProduct IdentificationProduct Hazard WarningCAS NumberUNC NumberNFPA Fire DiamondSafety Venting DecalsFlammable Gas WarningNo SmokingNo Open Flames

LABELING AND MARKINGS cont.Personal ProtectionPipeline LabelingAuthorized PersonnelPressure Vessel IdentificationCorporate Identification NumberEmergency Information Valve and Component

IdentificationAnnual Safety InspectionVent Stack Purge IdentificationStatic Ground Connection

MATERIALS

SATISFACTORY300 Series Stainless

SteelMonel InvarCopperBrassAluminum (with

exceptions)

UNSATISFACTORYCarbon SteelPlasticsNickel Steel

EXPLOSION PROOF METERSMSA Model 3 Calibrated for HydrogenMSA Model Passport Personal AlarmCosmotector Model XPO-317

TRAININGBOC Gases policy requires that all people

working with hydrogen be trained in accordance with BOC standards

OSHA’s Code of Federal Regulations, 29-1910.103 states “you must be trained and familiar with proper practices associated with the construction and use of a hydrogen system”

CUSTOMER TRAININGMSDS (Material Safety Data Sheet)General site reviewEmergency contact information

8 CAUSES OF HYDROGEN MISHAPSProcedural deficienciesPlanning deficienciesMaterial failureDesign deficienciesOperation and work area deficienciesMalfunctionMaterials incompatibilityContamination

STACK FIRE (controlled burn)

TANK SAFETIES (Pressure Relief Devices)

STACK PIPING ALL SAFETIES

STACK HEIGHT

SECOND STACK ON SOME TANKS

INDUSTRIAL FURNACE OPERATION

Flammable Atmosphere Introduction:Purge furnace with nitrogen until all

chambers are below 1% oxygenIgnite pilots and flame curtainsVerify furnace temp. > 1400°F

Proceed with hydrogen introduction

Flammable Atmosphere Removal:Establish nitrogen purge flowStop hydrogen flowVerify that the furnace contains less than 2%

hydrogenLower furnace temperature to below 1400°F

INDUSTRIAL FURNACE OPERATION

Additional Safety Interlocks:Low nitrogen tank levelLow nitrogen pressureLow nitrogen flowLow hydrogen flow

INDUSTRIAL FURNACE OPERATION

QUESTIONS?QUESTIONS?