A COMPOSITE PHASE-DIAGRAM OF STRUCTURE-H HYDRATES USING SCHREINEMAKERS GEOMETRIC APPROACH

A composite phase diagram is presented for Structure H (sH) clathrate hydrates. In this work, we derived the reactions occurring among the v arious phases along each four-phase (Ice/Liquid water, liquid hydrocar bon, vapor, and hydrate) equilibrium line. A powerful method (though s eldom used in chemical engineering) for multicomponent equilibria deve loped by Schreinemakers is applied to determine the relative location of all quadruple (four-phase) lines emanating from three quintuple (fi ve-phase) points. Experimental evidence validating the approximate pha se diagram is also provided. The use of Schreinemakers' rules for the development of the phase diagram is novel for hydrates, but these rule s may be extended to resolve the phase space of other more complex sys tems commonly encountered in chemical engineering.