CO-insertion mechanism based kinetic model of the Fischer–Tropsch synthesis reaction over Re-promoted Co catalyst

• Detailed kinetic model of FTS over promoted Co catalyst was developed.
• Model was derived based on the CO-insertion mechanism and LHHW methodology.
• Chain length dependent desorption of 1-olefins is used to explain the increase in growth probability and decrease in olefin-to-paraffin ratio with increase in carbon number.
• Physical meaningfulness of the model and its parameters was verified.
• A good prediction of the product formation rates for C1–15n-paraffins and C2–15 1-olefins for a range of process conditions was obtained.

A detailed kinetic model of the Fischer–Tropsch synthesis (FTS) product distribution based on the CO-insertion mechanism has been derived. The model was developed using the Langmuir–Hinshelwood–Hougen–Watson approach. The intrinsic kinetic parameters were estimated using a set of data obtained in a stirred tank slurry reactor with a rhenium promoted cobalt catalyst over a range of operating conditions (T = 478, 493, 503 K; P = 1.5, 2.5 MPa; H2/CO = 1.4, 2.1; WHSV = 1.0–22.5 NL/gcat/h). Physical meaningfulness of the model and its parameters was verified. Consistent with reported measurements, model predicts that adsorbed CO is the most abundant surface species. The observed increase in the chain growth probability factor and decrease in olefin-to-paraffin ratio with increase in carbon number is explained utilizing the chain length dependent desorption of 1-olefins concept.

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