Hydroprocessing of Petroleum - Spent Hydroprocessing Catalysts - page 34

Figure 3.8: Normalized above base temperature versus time on stream [From ref. 114 . Reprinted
with permission].
base temperature increase required to maintain a similar conversion. AXENS has also
introduced a series of catalysts some of which have superior HDS activities over their
conventional middle distillate HDS catalysts [115] . This is shown in Fig. 3.9 . Thus,
conventional HDS catalyst was initially more active, but with time on stream, the stability of
the improved catalysts was quite evident. Kuwait Catalyst Company has also introduced two
new catalysts, i.e., HOP-414 and HOP-467 catalysts, which as a combination can achieve the
target low sulfur levels using existing diesel hydrotreating facilities [116] . Criterion has
introduced the CENTINEL Ascent and CENTINEL Gold series of catalyst that are designed to
meet the ultra low sulfur specifications for diesel [117,118] . Finally, ART has developed the
sulfur minimization by ART (SMART) catalyst system with a remarkably high activity than
predecessor hydrotreating catalysts [119] .
Figure 3.9: Effect of catalyst type on hydrodesulfurization (HDS) activity [From ref. 115 .
Reprinted with permission].