Robert A. Stowe

Mercury porosimetry—breakthrough pressure for penetration between packed spheres

Abstract The mathematical relationships have been developed for describing the penetration of fluids into the void spaces of a collection of uniform solid spheres. The pressure required for initial penetration or “breakthrough” pressure is defined in terms of the porosity of the spherical model and the contact angle of the fluid. Calculated data, covering the porosity range of 47.64% to 25.95%, and contact angles of 90° to 180°, are presented. These relationships allow the determination of particle radius from standard mercury penetration and porosity data.

Butene dehydrogenation kinetics over Dow Type B catalyst

Abstract The kinetics of the dehydrogenation of butene to butadiene over a stabilized, commercial sample of Dow Type B Ca-Ni-PO 4 catalyst have been studied. The isothermal, integral reactor data were obtained over a range of space velocities from 104 to 3103 v/v/hr and a temperature range of 550–675 °C. Using a 20 1 volume ratio of steam to butene, conversions ranging from 5 to 72% were obtained. Also, the effect of steam volume ratios on conversion was determined in the range of 30 1 to 7 1 at 650 and 675 °C. The results are presented in terms of space velocity and temperature. The interpretation is made in terms of the amount of the total reaction presented by various fractions of a dimensionless reactor length. An apparent activation energy of 34–43 kcal/g mole is obtained from extrapolation of the data. Finally, a thorough and comprehensive theoretical integrated rate expression is developed to evaluate the kinetic rate constants from the experimental data. Relative adsorption coefficients for butadiene plus hydrogen and steam are evaluated as 15.3 and 0.15, respectively, with the activation energy 34–36 kcal/g mole. The expression is ks = 2.36 × 10 27 e −35,990 RT where k is in molecules per second and s is number of active sites per gram of catalyst.