KINETICS OF DEWAXING NEUTRAL OILS OVER ZSM-5

Four neutral oils were dewaxed and the kinetics were measured by a little used global technique based on measurements at constant extent of reaction. Over the range of commercial interest, each oil behaved as if a single lumped species controlled the reaction. The activation energy for the four oils differed, suggesting that the properties of the kinetically important lumps also differed. n-Paraffins in the oils determine the yield of dewaxed product, but these species are very reactive and are completely converted under commercial conditions. Under commercial conditions, waxy non-n-paraffins appear to control the kinetics. Oils with high molecular weights contained more highly branched but waxy non-n-paraffins and had the lowest activation energies. In addition to providing insights to the fundamental nature of neutral oil dewaxing, this simple method can be extended with empirical correlations to relate temperature, throughout, and neutral oil properties with product pour point.