Hydroprocessing of Petroleum - Spent Hydroprocessing Catalysts - page 45

catalytic reactors reached a commercial scale. Among those, the best known are bunker reactor
and quick catalyst replacement reactor (QCR). It should be noted that moving bed reactors
require special equipment and procedures for safe transfer of catalyst into and out of the
high-pressure and high-temperature vessels and reactors. This may include several
high-pressure vessels upstream and downstream of the reactor. With respect to the generation
of spent hydroprocessing catalysts, the processes employing moving bed reactors are
unimportant.
The first process employing ebullated bed reactor ( Fig. 3.13 ) was known as the H-Oil process
developed jointly by the City Services with Hydrocarbon Research Institute (HRI). The HRI
was joined by Texaco and later by Institut fran¸ais du petrole (IFP) to license H-Oil process,
whereas City Services jointly with Lummus and Amoco have been licensing similar process
known as LC-Fining. The changing crude supply patterns are reflected by a gradual increase in
the demand for ebullated bed reactors as it is supported by Fig. 3.14 [24] .
The ebullated bed reactors were designed to handle the most problematic feeds such as VRs
and toped heavy crudes having high contents of metals, asphaltenes, sediments as well as
dispersed clays and minerals. The flexibility of the operation of the ebullated bed reactors was
successfully demonstrated during coprocessing using the mixtures of VRs with coals as well
as VRs and plastics. Table 3.3 [120] shows some operating parameters which confirm that the
ebullated bed reactors are suitable for hydroprocessing heavy feeds containing more than
700 ppm of metals. This, however, cannot be achieved without significant catalyst inventory.
Because of the catalyst being in a continuous motion, particle size less than 1mm can be used
without any difficulties. This ensures a high level of catalyst utilization. However, for such thin
particles, mechanical strength requires an attention to prevent their breaking in the reactor, as it
Figure 3.14: Trends in demand for ebullated-bed reactors [From ref. 24 . Reprinted with
permission].