Authors: Jungshik Kang Wenping Ma Robert A Keogh Wilson D Shafer Gary Jacobs Burtron H Davis
Publish Date: 2012/10/03
Volume: 142, Issue: 11, Pages: 1295-1305
Abstract
The hydroisomerization and hydrocracking of long chain nparaffins and a Fischer–Tropsch wax produced with a cobalt catalyst were accomplished over a Pt–amorphous silica–alumina catalyst The relative conversion of the nhexadecane and noctacosane mixed feed greatly favored the higher carbon number compound even though the conversions of the pure hydrocarbons were the same within a factor of two or less when converted separately Thus vapor equilibrium plays a role for the conversion of the heavier alkanes and in this case the conversion essentially occurs with only the compound present in the liquid phase The single branched cracked products show a peak at the midcarbon number C8 and C14 for the two reactants but the peak for the multibranched product occurs at a higher carbon number Thus it appears that the multibranched products are primarily produced in a series reaction with the singly branched compounds being formed as the primary products The data for wax conversion are consistent with the competitive conversion operating for the higher carbon number compounds however the transport of intermediate carbon number products from the reactor occurs more rapidly than their formation rates by cracking reactions The data clearly show that the hydrocracking of wax is dominated by vapor–liquid equilibrium and that hydrocracking is initially controlled by the compounds present in the liquid phase
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