A Novel Pore Structure Tortuosity Concept Based on Nitrogen Sorption Hysteresis Data

Abstract

A corrugated pore structure model (CPSM−nitrogen)9 was employed to define a novel pore structure tortuosity concept. An empirical correlation is proposed for the prediction of tortuosity factors τCPSM as follows: τCPSM = 1 + A[(Dmax,eff − Dmin,eff)/Dmean](NS − 2)a. Constants A and a are adjustable parameters. The second factor reflects the influence of the intrinsic pore size distribution, and the third expresses the contribution of the nominal pore length parameter NS. The latter is, by definition, the number of pore segments forming a single corrugated pore of the CPSM pore configuration model and represents the frequency of pore cross section variation per unit length along a characteristic catalyst pellet dimension. The determination of NS and (Dmax,eff − Dmin,eff)/Dmean is accomplished by fitting the CPSM model over the pertinent nitrogen sorption hysteresis data. Coefficients A and a were found to be A = 0.69 and a = 0.58 by applying the empirical correlation for two specified materials of known to...