Configurational diffusion of asphaltenes in fresh and aged catalyst extrudates. Quarterly progress report, December 20, 1995--March 20, 1996

摘要

The objective of this research is to determine the relationship between the size and shape of coal and petroleum macromolecules and their diffusion rates i.e., effective diffusivities, in catalyst pore structures. That is, how do the effective intrapore diffusivities depend on molecule configuration and pore geometry. This quarter, adsorptive diffusion of both coal and petroleum asphaltenes in THF into porous catalysts were performed. A mathematical model with linear adsorption isotherm for asphaltene diffusion was developed. The molecular weight distribution of both asphaltenes were ascertained by GPC using polystyrene standards. The asphaltene diffusion data were simulated fairly well by the mathematical model, and linear adsorption constants were obtained for asphaltene fractions with different equivalent polystyrene molecular weights.