TABLE OF CONTENTS Several detailed reviews of the commercial and emerging processes used for hydroprocessing of heavy feeds were published elsewhere (437 439). Simplified schematics of the petroleum refinery shown in Figure 2.1 indicated the presence of several catalytic units operating in a hydroprocessing mode on the site of the refinery. Among the units, the hydroprocessing of distillates from atmospheric distillation and from FCC, as well as the naphtha fraction from coking are not covered by this review. The properties of heavy feeds and those of the anticipated products after hydroprocessing of the former determine the selection of catalysts and type of reactors. Thus, every unit may require a different type of catalyst to achieve an optimal performance of the reactors. Also, several types of hydroprocessing reactors may be found on the site of the same refinery.
Simplified schematics of the catalytic reactors which have been used commercially are shown in Figure 8.1, whereas the typical operating ranges of these reactors are summarized in Table 8.1 (437). The features of these reactors indicate an importance of the proper selection of catalysts, the size and shape of the catalyst particles in particular, to ensure an efficient and continuous operation. In addition, the properties of heavy feeds must be taken into consideration to achieve the optimal matching of catalysts with reactor. This is the primary objective of this chapter, rather than to give an exhaustive review on catalytic reactors and systems.
