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Alternative Fuels for Transportation
• Boiloff gas is highly diffusive
• Flow-induced static charge generation
• Boiloff vent rate from storage tanks/fuel tanks is typical to maintain cold temperature in tank
• Liquifies quickly, easily boils by heat transfer into the 20 K
liquid
• Rapid phase transition from liquid to gas can cause pressure
explosions
• Liquid quickly contaminates itself by condensing gases from air
contact
2. Pressure
• Stored under modest pressure to suppress boiling
3. Chemical
• Evolved gas is cold, otherwise the same concerns as gaseous
hydrogen
4. Temperature
• Cryogenic burns, especially eyes
• Lung damage by cold vapor inhalation
• Possible hypothermia working near these systems
• Condensation of air near LH 2 systems if insulation allows heat
leak paths; can lead to oxygen rich zones near systems
5. Materials issues
• Mechanical stresses generated by thermal contraction
• Embrittlement of metal
• Mild steels susceptible to cracking at cryogenic temperatures
• Materials have low specific heats at cryogenic temperatures, easy
heat transfer
6. Toxicological issues
• Asphyxiation in confined spaces
• Frostbite from acute exposure
• Hypothermia possible from long exposure
• No other toxic concerns
From the list, the hazard due high-pressure, for gaseous storage, and
rapid phase transition from liquid to gas, in cases of liquid storage, seems
the most dangerous scenario for the transport sector due to the fact that
these hazards develop into the ultimate scenario of fire and explosions.
These issues are of particular importance for the risk related to hydrogen
Alternative Fuels for Transportation
• Boiloff gas is highly diffusive
• Flow-induced static charge generation
• Boiloff vent rate from storage tanks/fuel tanks is typical to maintain cold temperature in tank
• Liquifies quickly, easily boils by heat transfer into the 20 K
liquid
• Rapid phase transition from liquid to gas can cause pressure
explosions
• Liquid quickly contaminates itself by condensing gases from air
contact
2. Pressure
• Stored under modest pressure to suppress boiling
3. Chemical
• Evolved gas is cold, otherwise the same concerns as gaseous
hydrogen
4. Temperature
• Cryogenic burns, especially eyes
• Lung damage by cold vapor inhalation
• Possible hypothermia working near these systems
• Condensation of air near LH 2 systems if insulation allows heat
leak paths; can lead to oxygen rich zones near systems
5. Materials issues
• Mechanical stresses generated by thermal contraction
• Embrittlement of metal
• Mild steels susceptible to cracking at cryogenic temperatures
• Materials have low specific heats at cryogenic temperatures, easy
heat transfer
6. Toxicological issues
• Asphyxiation in confined spaces
• Frostbite from acute exposure
• Hypothermia possible from long exposure
• No other toxic concerns
From the list, the hazard due high-pressure, for gaseous storage, and
rapid phase transition from liquid to gas, in cases of liquid storage, seems
the most dangerous scenario for the transport sector due to the fact that
these hazards develop into the ultimate scenario of fire and explosions.
These issues are of particular importance for the risk related to hydrogen