unit operations of chemical engineering warren l mccabe

For a first-order model, the time constant is computed for common particle geometries showing its dependency with the Thiele modulus. An approach to obtain low-order models, based on an approximate model matching, is proposed. This implies that, contrary to the steady-state case, an exact simple modeling of the reaction rate dynamics is not possible. However, the resulting transfer function is infinite-dimensional. It is shown that the DEF becomes the transfer function of a model governing the dynamics of the catalyst particle reaction rate. As a preliminary step, a Laplace domain approach is used to introduce a dynamic EF (DEF) concept as a linear operator that transforms reaction rate signals from surface/bulk to catalyst particle conditions. The aim of this paper is to extend the EF approach to obtain a simple model for the dynamics of the catalyst particle total reaction rate.

As a consequence, only few arithmetic operations to obtain the catalyst particle total reaction rate have to be made, avoiding in this form repeated solutions of the more sophisticated distributed parameter model. EF is to express the reaction rate in a catalyst particle by its rate under surface/bulk conditions multiplied by the EF. For steady-state conditions, the effectiveness factor (EF) approach has been primarily used to reduce the model dimensionality, which yields an important computational effort during reactor design stages. Other unique topics of this text include diafiltration, adsorption and membrane operations.Models for heterogeneous reactors are composed of distributed parameter ordinary and partial differential equations to describe balances both for a fluid and a catalyst particle. Almost 30% of the problems have been revised or are new, some of which cover modern topics such as food processing and biotechnology. Now in its seventh edition, the text still contains its balanced treatment of theory and engineering practice, with many practical, illustrative examples included. Separate chapters are devoted to each of the principle unit operations, grouped into four sections: fluid mechanics, heat transfer, mass transfer and equilibrium stages, and operations involving particulate solids. Since 1956, this text has been the most comprehensive of the introductory, undergraduate, chemical engin. Unit Operations of Chemical Engineering, 7th edition continues its lengthy, successful tradition of being one of McGraw-Hill's oldest texts in the Chemical Engineering Series.

Unit Operations of Chemical Engineering (Int'l Ed)

Unit operations of chemical engineering warren l mccabe