| Abstract
| - A unified model for the description of vapor- and liquid-phase hydroconversion has been developed. Thehigh isomer yield, which is typical for the shape selectivity exhibited by Pt/H−ZSM-22 at vapor-phaseconditions, is still observed at liquid-phase conditions. However, the molar cracking yield is enhanced by atleast 10 mol % when operating at liquid-phase conditions. The latter effect is mainly due to an increasedphysisorption competitiveness of lighter alkanes, which also results in enhanced cracking of lighter alkanes.The effect amounts to approximately 3 orders of magnitude for a difference of 2 in carbon number. Theseaggregation state effects are accounted for in the model through (i) liquid phase thermodynamic nonideality,(ii) destabilization of the physisorbed state by compression of the adsorbate by the bulk fluid, and (iii) carbeniumion stabilization by sorbent solvation by the bulk fluid. F-values of the order of 103 indicate the model'sadequacy in describing the observed phenomena.
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