ON EFFECTIVENESS FACTOR CALCULATIONS

GOTTIFREDI JUAN,; GONZO ELIO E.

CHEMICAL ENGINEERING SCIENCE

Elsevier

Lugar: Holanda; Año: 2006 vol. 61 p. 7563 - 7563

0009-2509

Abstract We were very surprised when we read this paper. It took us by surprise. Exactly twenty years ago, we published two reviews, one in Advances in Transport Processes, vol. IV (A perturbation and matching technique to solve transport phenomena problems) and other in the Whitaker, Cassano Eds. book, Concepts and Design of Chemical Reactors, entitled "Effectiveness Factor Calculations"; where the asymptotic solutions for the effectiveness factor at low and large values of the Thiele modulus were set up and solved. Even more, at that time several matching expressions were proposed to estimate effectiveness factors (Wedel and Luss, Churchill, etc.) and we found a general expression to match the asymptotic solutions which cover any pellet geometry, kinetic expression and catalytic activity distribution into the pellet. Including also the concentration dependence of effective diffusivity of the key component and the effective conductivity of the pellet. In our review on Effectiveness factor Calculation, a two term matching expression was presented. The first term is the very simple equation for effectiveness factor calculation which is enough accurate for most engineering applications.