The Development of a Macro Kinetic Model for a Commercial Co/Pt/Al₂O₃ Fischer−Tropsch Catalyst

Abstract

An experimental study was performed with an aged Co/Pt/Al 2 O 3 catalyst in a laboratory slurry reactor to develop a macrokinetic expression for the Fischer-Tropsch (FT) synthesis. A semiempirical model was found to be the preferred two-parameter rate equation of the reaction. However, it was shown that this model is virtually indistinguishable from a mechanistically derived three-parameter rate model that assumes the following kinetically relevant steps in the cobalt-FT synthesis: CO dissociation occurs without hydrogen interaction and is not a rate-limiting step; the first hydrogen addition to surface carbon and the second hydrogen addition to surface oxygen are the rate-determining steps.

In situ magnetometer study on the formation and stability of cobalt carbide in Fischer–Tropsch synthesis

“…Direct comparison of catalyst performance can only be done at exactly the same reactor conditions. As this is cumbersome to achieve experimentally, Fischer-Tropsch synthesis activities were expressed in terms of the dimensionless relative intrinsic activity factor (RIAF), defined as the normalized rate constant (k) of the published [29] kinetic equation:…”

Generalized kinetic model for iron and cobalt based Fischer–Tropsch synthesis catalysts: Review and model evaluation

“…performed a macro-kinetic study for cobalt and iron FTS catalysts wherein operating conditions were systematically varied in a wide range [6,7]. They found that equations 1 and 2 show systematic statistical deviations and therefore proposed different equations (equation 3 and 4) for cobalt and iron respectively.…”

GTL using efficient cobalt Fischer-Tropsch catalysts

“…When mechanistic pathways are not available from fundamental knowledge, empirical studies are done where macro kinetic models are derived [34] for a large set of feasible mechanisms and tested against laboratory data. The best candidate model is then identified using rigorous statistical criteria [35] and a reaction mechanism postulated for further study.…”