Phase behavior of the n‐butane‐hydrogen sulphide system

Previous work on binary and multicomponent systems containing hydrogen sulphide or n‐butane is briefly reviewed and the anomolous behavior of the hydrogen sulphide with hydrocarbons and of the n‐butane with non hydrocarbons is noted. Experimental equipment suitable for studying the phase behavior of simple or complex mixtures is described. The novel features include a new method for obtaining equilibrium between phases, for sampling, and for locating the meniscus between phases. Experimental data have been obtained for the n‐butane‐hydrogen sulphide system at seven temperatures between 100°F. and 275°F. and pressures up to 1165 p.s.i.a. A tendency toward azeotropic behavior was observed but an azeotrope was never fully developed. Equilibrium ratios for hydrogen sulphide and n‐butane were calculated at convergence pressures of 1000 p.s.i.a. at 240°F. and 800 p.s.i.a. at 275°F. The results agreed well with those determined from generalized correlations. It is concluded that the presence of hydrogen sulphide does not influence the behavior of n‐butane abnormally at the temperatures and pressures studied.