Mercury Porosimetry Hysteresis and Entrapment Predictions Based on a Corrugated Random Pore Model

This paper advances the concept of mercury porosimetry hysteresis and entrapment, through the development of a probabilistic model simulating the mercury penetration-retraction operations, applied to a one-dimensional model of non-intersecting corrugated pores. The fundamental aspect on which the development of the model is based, is the experimentally observed phenomenon of mercury column breaking, occurring during its capillary flow along a corrugated pore. A mercury column is assumed to break and remain trapped within wide pore sections. Criterion for the entrapment to occur is the condition that the “pore constriction ratio A. ” defined as the ratio of a pore segment size and that of the next in the direction of mercury flow segment, to be lower than some critical value 𝛌c (O>𝛌c >1). Theoretical predictions of the statistical model using a Normal, a Beta and a Bimodal probability density function as the intrinsic pore size distribution have shown that realistic hysteresis loops can be obtained and widely varied amounts (0-85%) of mercury entrapment can be predicted. The potential of the model has been also tested through the curve fitting of MP experimental data obtained on samples of three commercial HDS catalysts.