Melting and crystallization of paraffins

In mixed feedstocks consisting of two or more crude oils or blends of different fractions, the ratio of components is usually selected experimentally. This sort of selection process may be very laborious and may involve technical difficulties. A rather universal method was proposed in for determining the optimal component composition of mixtures on the basis of extremal or polyextremal relationships - confirmed by many experiments - for the physicochemical parameters of mixtures as a function of the component ratio or the concentration of an additive, these relationships indicating nonadditivity of certain properties of mixtures of petroleum disperse systems. Any observed extremum. is an indication of a state of the feedstock mixture that may be optimal. Readily determinable parameters are used to reveal such singular points - parameters such as the initial or final boiling point, melting point or crystallization point, viscosity, optical characteristics, or other characteristics. It is noteworthy that these parameters are directly related to the structure of petroleum disperse systems on different scales of interaction, namely, macroscopic, mesoscopic, and microscopic. The cause of sharp changes in properties should evidently be sought in the physics of such phenomena as transformation of structures, rupture and formation of bounds, transition processes,more » etc. Here we are reporting on an investigation of mixtures of alkanes and on the preparation of mixed feeds for commercial processes. We have analyzed experimental data on the melting point and crystallization point of paraffins that are the starting material in the production of synthetic fatty acids (SFA) at the Volgograd refinery.« less