Clathrate phase equilibria for the ternary water-phenol-methane system were studied. This system consisted of two hosts and one guest. Four-phase equilibrium boundary for this ternary system was measured over the temperature and pressure ranges of 283.2 K and 37.0 bar to 323.6 K and 275.0 bar. Isobaric equilibrium compositions were also measured at 50.0 bar and several temperature ranges. Several types of three-phase and four-phase diagrams were obtained, which were dependent on the feed concentration of methane. Separation of phenol from aqueous solution was depicted in a diagram on the basis of methane-free concentration. A schematic pressure-temperature diagram for the ternary and three corresponding binary systems was presented. (C) 1998 Elsevier Science B.V. All rights reserved.