Applications hydrocracking

A fairly large number of patents has been issued describing the application of aluminum-deficient Y zeolites in different areas of catalysis. Ultrastable Y zeolites have been used in the preparation of catalysts applied in hydrocarbon cracking, e.g. (94,95) hydrocracking, e.g. (96,97) hydrotreating, e.g. (98) and disproportionation, e.g. (99). 

Aluminum chloride has extensive commercial applications. It is used primarily in the electrolytic production of aluminum. Another major use involves its catalytic applications in many organic reactions, including Friedel-Crafts alkylation, polymerization, isomerization, hydrocracking, oxidation, decarboxylation, and dehydrogenation. It is also used in the production of rare earth chlorides, electroplating of aluminum and in many metal finishing and metallurgical operations. 

Platinum also is used extensively as a catalyst in hydrogenation, dehydrogenation, oxidation, isomerization, carbonylation, and hydrocracking. Also, it is used in organic synthesis and petroleum refining. Like palladium, platinum also exhibits remarkable abdity to absorb hydrogen. An important application of platinum is in the catalytic oxidation of ammonia in Ostwald s process in the manufacture of nitric acid. Platinum is installed in the catalytic converters in automobile engines for pollution control. 

Refinery alkylation processes utilize either sulfuric acid or hydrofluoric acid as reaction catalysts. The feedstock for both alkylation processes originates primarily from hydrocracking and catalytic cracking operations. Coker gas oils also serve as feedstock in some applications. The differences and similarities between sulfuric acid alkylation and hydrofluoric acid alkylation are shown in TABLE 2-5. Typical alkylation reactions are shown in FIGURE 2-9. A sulfuric acid alkylation unit is illustrated in FIGURE 2-10. 

Trickle-bed reactors usually consist of a fixed bed of catalyst particles, contacted by a gas liquid two-phase flow, with co-current downflow as the most common mode of operation. Such reactors are particularly important in the petroleum industry, where they are used primarily for hydrocracking, hydrodesulfurization, and hydrodenitrogenation other commercial applications are found in the petrochemical industry, involving mainly hydrogenation and oxidation of organic compounds. Two important quantities used to characterize a trickle-bed reactor are... 

Hydrocracking catalysts are dual functional, containing both hydrogenation and cracking sites. The best choice of catalyst for a specific situation requires a particular balance between these two functions. Table I shows some applications of hydrocracking and the characteristics of the families of catalysts that have evolved for accomplishing the indicated conversions. 

The hydrocracking technology and the families of industrial hydrocracking catalysts developed during the past decade have excellent prospects for increased application during the next. 

While the definitions of the various hydroprocesses are (as has been noted above) quite arbitrary, it may be difficult, if not impossible, to limit the process to any one particular reaction in a commercial operation. The prevailing conditions may, to a certain extent, minimize, cracking reactions during a hydrotreating operation. However, with respect to the heavier feedstocks, the ultimate aim of the operation is to produce as much low-sulfur liquid products as possible from the feedstock. Any hydrodesulfurization process that has been designed for application to the heavier oils and residua may require that hydrocracking and hydrodesulfurization occur simultaneously. 

The choice of processing schemes for a given hydrocracking application depends upon the nature of the feedstock as well as the product requirements... 

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