Liquid-vapor equilibria in the hydrogen-nitrogen and deuterium-nitrogen systems

A recirculation type of apparatus with a novel liquid‐sampling system was used to obtain liquid‐vapor equilibrium data for the hydrogen‐nitrogen and deuterium‐nitrogen systems at 90° and 95°K. and pressures up to 1,000 lb./sq. in. abs. The data obtained show an average scatter in liquid compositions of the order of 0.01%, thus proving the feasibility of the new liquid‐sampling system. The vapor samples are shown by thermodynamic analysis to scatter less than 0.1%. Deuterium is slightly more soluble in liquid nitrogen than hydrogen; the relative volatility is 1.198 at 90°K. and about 1.177 at 95°K. The relative volatility is practically independent of pressure; thus at 90°K. the relative volatility decreases from 1.198 at 100 lb./sq. in. abs. to 1.196 at 1,000 lb./sq. in. abs., but this range of values is well within the experimental error.