Heat and Thermodynamics

7.9 Liquefaction of Hydrogen

Critical temperature of hydrogen is 33.2 K. Hence, it must be cooled below about 100 K in order that it may be cooled by throttle expansion. The optimum input temperature and pressure for maximum yield of liquid hydrogen is between 63 K and 80 K and 160 atmospheres, the gas expanding to 1 atmosphere.

Figure 7.13 shows the flow diagram for hydrogen of the liquefier of the Mond laboratory of the Royal Society at Cambridge. In this apparatus, two separate circulations are used, which are as follows:

 

 

Fig. 7.13 Flow diagram for hydrogen to be liquified

1. one that is used mainly for cooling the apparatus;
2. other where ...