Hydrodynamic Effects in Scaled-Down Hydrocracking of Iron-Based Fischer−Tropsch Wax

Iron-based low-temperature Fischer−Tropsch (LTFT) wax was hydrocracked in upflow and downflow mode of operation using fixed-bed bench-scale and pilot-scale reactors. Heavy paraffin conversion was higher in the upflow mode whereby lower diesel selectivities were observed. It was also shown that the d...

Full description

Saved in:
Bibliographic Details
Published in:Industrial & engineering chemistry research 2008-12, Vol.47 (24), p.10086-10092
Main Authors: van der Merwe, Werner, Loudon, Dylan, Leckel, Dieter
Format: Article
Language:English
Subjects:
Applied sciences
Chemical engineering
Exact sciences and technology
Hydrodynamics of contact apparatus
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Iron-based low-temperature Fischer−Tropsch (LTFT) wax was hydrocracked in upflow and downflow mode of operation using fixed-bed bench-scale and pilot-scale reactors. Heavy paraffin conversion was higher in the upflow mode whereby lower diesel selectivities were observed. It was also shown that the diesel properties are a function of the mode of operation. The results indicate the presence of macrokinetic (hydrodynamic) limitations on the overall hydrocracking rate that is present due to the comparatively low liquid superficial velocity. The higher hydrocracking efficiency in the upflow mode is likely due to complete particle wetting (compared to the partial wetting in the downflow mode) that enhances both external and internal mass transfer of the liquid phase reagent. The results highlight the danger of scaled-down reactors that might not be representative of industrial operation.
ISSN:0888-5885
1520-5045
DOI:10.1021/ie800894w