THE RELEVANCE OF OVERALL HEAT-TRANSFER COEFFICIENTS IN THE SIMULATION OF CATALYTIC FIXED-BED REACTORS WITH THE HETEROGENEOUS ONE-DIMENSIONAL MODEL

Several expressions, including one introduced in this work, for overall heat transfer coefficients are used to evaluate the performance of the heterogeneous one-dimensional (Het 1-D) model for catalytic fixed bed reactors with simultaneous heat exchange. From testing a large amount of reacting and operating conditions, it is shown that very precise estimations, compared to the results of the heterogeneous two-dimensional model, can usually be achieved up to critical conditions for parametric sensitivity with those expressions accounting for the effect of temperature on the chemical reaction rate. Some conditions with relatively large ratios of tube to particle diameters may lessen the accuracy of the Het 1-D model, and quantitative bounds are identified for them. The relevance of the Het 1-D model compared to the pseudohomogeneous 1-D model is also emphasized.