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2/5
A 401
About Helium and hydrogen
GB
02760
- Edition
01
- Februar
y
05
GB
02760
- Edition
01
- Februar
y
05
3/5
A 401
About Helium and hydrogen
Hydrogen
Hydrogen (H
2
) is the lightest element, has a gaseous specific gravity
of 0.0695 and a boiling point of -423 F (-252.8 C) at atmospheric
pressure. It is a colorless, odorless, tasteless, flammable gas found at
concentrations of about 0.0001 % in air. Hydrogen is produced by
several methods, including steam/methane reforming, dissociation
of ammonia, and recovery from by-product streams from chemical
manufacturing and petroleum reforming. Hydrogen can be stored and
transported as either a gas a cryogenic liquid.
Hydrogen is flammable in the concentration range 4 % to 75 % in
air or oxygen and can detonate in the range 18 % to 60 % in air or
oxygen .
Compared to the helium at same purity, hydrogen is less expansive
than helium, but on the field the reality is different because to use
Hydrogen under safe conditions you have to mix the Hydrogen with
an inert gas like Nitrogen; the concentration of Hydrogen in Nitrogen
must be lower the 5 % to be non-flammable in air or Oxygen.
And under this condition the price of the mixture is becoming more
expansive.
Hydrogen ( Air Liquide and Linde sources, Europe)
Purity
Average market price (2004)
in
€
/m
3
99,999 %
13
99,995 %
12
99,5 %
9
Mixture
95 % N2 + 5 % H2
25 to 30
Alcatel Vacuum Technology France - User's Manual ASM 182/192 TD+ - ASM 192 T2D+
Alcatel Vacuum Technology France - User's Manual ASM 182/192 TD+ - ASM 192 T2D+