THE TERNARY-SYSTEM (N-HEPTANE PLUS DOCOSANE PLUS TETRACOSANE) - THE SOLUBILITY OF MIXTURES OF DOCOSANE AND TETRACOSANE IN HEPTANE AND DATA ON SOLID-LIQUID AND SOLID-SOLID EQUILIBRIA IN THE BINARY SUBSYSTEM (DOCOSANE PLUS TETRACOSANE)

In this paper experimental data on the solid-liquid and solid-solid eq uilibria in the binary system (docosane + tetracosane) and solid solub ility data in the ternary system (heptane + docosane + tetracosane) ar e presented. For 14 binary mixtures of the two heavy alkanes, DSC meas urements were performed to detect the solid-liquid and solid-solid pha se transition temperatures. Solid disappearance temperatures were meas ured for 14 mixtures of docosane and tetracosane dissolved in various quantities of heptane. The experimental results reveal that the solubi lity curves found in the ternary system correspond to the phase behavi or of the binary subsystem studied. At low concentrations of heptane, probably almost ideally mixed crystals are in equilibrium with the liq uid phase, while at high heptane concentrations, the solid-liquid equi librium involves most likely different nonideal solid phases.