Hydrogen hydrocracking

Throughout these studies, no product other than propane was observed. However, subsequent studies by Sinfelt et al. [249—251] using silica-supported Group VIII metals (Co, Ni, Cu, Ru, Os, Rh, Ir, Pd and Pt) have shown that, in addition to hydrogenation, hydrocracking to ethane and methane occurs with cobalt, nickel, ruthenium and osmium, but not with the other metals studied. From the metal surface areas determined by hydrogen and carbon monoxide chemisorption, the specific activities of... 

Fig. 43. Reaction scheme for the hydrogenation, hydrocracking and deuterium exchange of cyclopropane over metal catalysts.

On the other hand, destructive hydrogenation (hydrocracking) is character-... 

Hydrogenation Hydrocracking Residual products Light heating oil, gasoline. Catalytic treatment at high... 

The DCL process contains two steps dissolution of coal in the preheater (accompanied by several fast reactions) and subsequent hydrogenation/hydrocracking reactions (slow reactions) in a three phase slurry reactor. 

Inherent coal minerals are readily available and inexpensive catalysts for liquefaction, hydrogenation/hydrocracking and heteroatom removal reactions. In recent years, experimental work has been carried out to determine (a) liquefaction behavior of various coals with different mineral matter contents, (b) liquefaction behavior by adding various mineral matter in or to a particular coal or by reducing the mineral matter contents of a coal by some physical means and (c) liquefaction behavior in the presence of a variety of externally added catalysts. Some of these studies are briefly described below. 

In general, one of the major problems associated with the use of most of the solid catalysts described above is related to their regeneration. Unless regeneration can be carried out by washing and/or hydrogenation-hydrocracking, the process will certainly become complicated. 

Two areas listed in Table 1 were not discussed—hydrocarbon-water binaries and petroleum fractions. For the former systems only eight systems of experimental VLE data (ethylene, propylene, 1-butene, 1-hexene, n-hexane, cyclohexane, benzene, and n-nonane) were available. Use of solubility data and calculated VLE data added only five more systems (propane, propyne, cyclopropane, n-butane, and 1,3-butadiene). For petroleum fraction systems only three sources and seven systems have been characterized well enough to use in analytical correlations to be tested. These systems Include three naphtha-fuel oil systems, two hydrogen-hydrocrackate fractions, and two hydrogen-hydrogen sulfide-hydrocrackate fractions. No reasonable work can be done without additional data. 

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