Hydrogen
287
• In liquid form, LH2: in super isolated tanks as cryogenic liquid (at
–253°C, or 20K).
• In a bonded form, in a solid compound by: adsorbing (carbon structures), absorbing (simple crystalline hydrides), or chemically reacting (complex and chemical hydrides).
• in a fluid compound form by chemically reacting (e.g., methanol,
ammonia, etc.).
Basic hydrogen storage criteria are:
• Weight Density (kg H 2 /storage system weight)
• Volumetric Density (kg H 2 /storage system volume)
• Reliable
• Compatible with available/planned infrastructure
• Safety: normal operation and emergency situations
• Service Life 15 years
• Cost (purchase and operative) High capital cost, low operating cost
• Refueling (fast filling time)
Each of these technologies has its own advantage, but only the second and
third one seem to be viable for onboard storage, because of complexity and
continuous energy requirements for the cryogenic solution.
Nickel metal hydride systems as hydrogen reservoirs assure high volumetric energy density (Figure 9.21) while excessively weighting vehicle power
train (Burke et al., 2005). Volume reduction is appealing but metal hydride
technology has to be further developed to reduce risk and costs. Similarly,
carbon nanofibers-tubes reduce tank volume but the technical maturity is
unsuited to practical applications.
Pressurized tank storage (Figure 9.22) has the advantage of rapid charge/
discharge times and of relatively lower complexity; metal hydrides have
the advantage of reduced safety constraints (their pressure is very low) and
higher energy per unit of volume, but they are more complicated to manage
because of the need of thermal management and have longer recharging
times.
The design of the vehicle is simplified when pressurized vessels store
hydrogen onboard. High-pressure tanks, similar to what was used in the
Cute project, assure long operating life (20 years and more) and exhibit moderate costs and straightforward control, thus being a mature, reliable, and
low risk technology. However, hydrogen production and distribution costs
are high so that an accurate WTT analysis is required to evaluate economic
and energetic impact of pressurized vessel technology.
287
• In liquid form, LH2: in super isolated tanks as cryogenic liquid (at
–253°C, or 20K).
• In a bonded form, in a solid compound by: adsorbing (carbon structures), absorbing (simple crystalline hydrides), or chemically reacting (complex and chemical hydrides).
• in a fluid compound form by chemically reacting (e.g., methanol,
ammonia, etc.).
Basic hydrogen storage criteria are:
• Weight Density (kg H 2 /storage system weight)
• Volumetric Density (kg H 2 /storage system volume)
• Reliable
• Compatible with available/planned infrastructure
• Safety: normal operation and emergency situations
• Service Life 15 years
• Cost (purchase and operative) High capital cost, low operating cost
• Refueling (fast filling time)
Each of these technologies has its own advantage, but only the second and
third one seem to be viable for onboard storage, because of complexity and
continuous energy requirements for the cryogenic solution.
Nickel metal hydride systems as hydrogen reservoirs assure high volumetric energy density (Figure 9.21) while excessively weighting vehicle power
train (Burke et al., 2005). Volume reduction is appealing but metal hydride
technology has to be further developed to reduce risk and costs. Similarly,
carbon nanofibers-tubes reduce tank volume but the technical maturity is
unsuited to practical applications.
Pressurized tank storage (Figure 9.22) has the advantage of rapid charge/
discharge times and of relatively lower complexity; metal hydrides have
the advantage of reduced safety constraints (their pressure is very low) and
higher energy per unit of volume, but they are more complicated to manage
because of the need of thermal management and have longer recharging
times.
The design of the vehicle is simplified when pressurized vessels store
hydrogen onboard. High-pressure tanks, similar to what was used in the
Cute project, assure long operating life (20 years and more) and exhibit moderate costs and straightforward control, thus being a mature, reliable, and
low risk technology. However, hydrogen production and distribution costs
are high so that an accurate WTT analysis is required to evaluate economic
and energetic impact of pressurized vessel technology.