Kinetic modeling of the Fischer-Tropsch synthesis in a slurry phase bubble column reactor using Langmuir-Freundlich isotherm

We employed the Langmuir-Freundlich isotherm for Fischer-Tropsch synthesis as a modification of the commonly used Langmuir isotherm, because the Langmuir-Freundlich isotherm can predict the adsorption of gases at solid absorbent more accurately than Langmuir isotherm. Several mechanisms for kinetic modeling of the Fischer-Tropsch synthesis have been developed in which the Langmuir isotherm is the basis of kinetic modeling of the catalytic reactions. Using Langmuir-Freundlich-Hinshelwood (LFH) model, the results of CO conversion in a slurry bubble column reactor show a very good agreement with the experiment. Moreover, we used fugacity instead of the pressure that leads to improve the accuracy of the new kinetic model. The fugacity term has been considered here by using Peng-Robinson Equation of State, modified by Gasem et al. The new kinetic model with fugacity is applied for modeling of a slurry bubble column reactor over the wide range of the reactor conditions of 523-563 K, 0.95-2.55 MPa and H-2/CO ratio: 0.65-1.51. The results of the new kinetic LFH-fugacity model shows the Average Absolute Deviation percentage (AAD%) of 4.25% for the CO conversion while this value is about 10.89% using the original equation based on langmuir isotherm. (C) 2011 Elsevier B.V. All rights reserved.