Hydrogen liquefaction Joule-Thomson effect

Hydrogen and helium have very low inversion temperatures, i.e., -80°C, and -240°C, respectively. Thus, at ordinary temperatures, these gases get heated up instead of being cooled in Joule-Thomson s expansion. But, if hydrogen is first cooled below -80°C and helium below -240°C, then these gases also get cooled down on Joule-Thomson expansion. Joule-Thomson effect was used by Linde in the liquefaction of the gases. The Linde s process is described below ... 

---