Established Methods Based on Compression and Cryogenics - Hydrogen Generation, Storage, and Utilization - page 77

FIGURE 5.1 A summary of current status of hydrogen storage technologies in terms of weight, volume,
and cost. These values are estimates from storage system developers and the R&D community and will
be continuously updated by DOE as new technological advancements take place. Source : Reproduced
with permission from http://www1.eere.energy.gov/hydrogenandfuelcells/storage/tech_status.html [2].
(See color insert.)

5.2 HIGH PRESSURE COMPRESSION

A common and simple method for storing and transporting hydrogen is to
compress hydrogen into a fixed volume (in a metal cylinder or tank) at high
pressure, so that the mass density of hydrogen will be increased. If under
high pressure P , the mass of compressed hydrogen is m H , the tank volume
and mass are V tank and m tank , the effective gravimetric and volumetric capaci-
ties are

m m

V

′ =

H

′ =

H

ρ and ρ .

M V

m + m

H tank tank

The parameters P , V tank , and m H are linked by the equation of state of
hydrogen, f ( P , V tank , T ) = 0. The simplest approximation is the law of an
ideal gas,

PV

tank =

nRT .

(5.6)

where

m
M

H

n = ,