Making liquid hydrogen ?

Question

Does anyone know how hydrogen is liquefied and what pressure/temperature is involved?

For example if the starting pressure is higher will this affect how low you need to refrigerate the gas prior to expansion?

I cant seam to find any math or proper explanation around the hydrogen liquification process so any help would be greatly appreciated

Answer 1

You're looking at temperatures in the minus hundreds (F) to liquify a gas.  Higher pressures will reduce the evaporation, so yes, liquification would occur at somewhat higher temps.

Answer 2

Check this out....

http://www-safety.deas.harvard.edu/servi...

Answer 3

Check the ref.

Answer 4

minus 173 at normal atmospheric conditions, the higher the altitude the higher the temperature it will condense