(606g) A 1-D Trickle-Fixed-Bed Recycle Reactor Model for the Fischer-Tropsch Synthesis

A fixed-bed recycle reactor for Fischer-Tropsch synthesis on iron and cobalt catalysts has been modeled using Visual Basic Applications for Excel. The model inputs give great flexibility in the form and choice of kinetic model. Catalyst particle geometries built into the model include spheres, cylinders, hollow cylinders and trilobes. The model has been partially validated with Sasol Arge Trickle-Fixed-Bed reactor data and Shell Bintulu Plant data. Product selectivity may be user-specified or predicted using an empirical model. Attempts to refit the constants of the olefin readsorption model developed by van der Laan and Beenackers to data published by the Chinese Institute of Coal Chemistry for an industrial iron catalyst have not been satisfactory, but modification and integration of the model continues. This 1-D reactor model gives insight into operating envelopes of reactor conditions for FT reactors and aids in understanding the critical factors in early stages of reactor design and optimization, especially for CTL, BTL, and GTL. Specifically, parametric studies show that recycle is required for good temperature control, that choice of kinetic model is significant to model predictions, and that particle geometry greatly affects reactor size and pressure drop.