STRUCTURE-H HYDRATE PHASE-EQUILIBRIA OF PARAFFINS, NAPHTHENES, AND OLEFINS WITH METHANE

Initial phase equilibrium data are reported for 10 methane + liquid hy drocarbon systems forming structure H hydrates in the pressure range o f 1-6 MPa. Four-phase equilibrium conditions were measured for each sy stem, with paraffinic, naphthenic, and olefinic liquid hydrocarbons fi lling the large cage of structure H, and methane stabilizing the two s maller cages present in the hydrate. Many of these liquid hydrocarbons constitute a small fraction of crude oils and condensates, and the hi gh stability and relative ease of formation of structure H suggest a p ossible impact of these hydrates upon hydrocarbon facilities.