60
environment, precious metal-type catalysts (e.g., Pt or Pd) are also used as the
second- stage catalyst, especially in diesel HDT units for improvement of cetane
number. Some of the catalyst suppliers who offer HDT/HDS catalysts include
Haldor Topsoe, Axens (IFP), Criterion, Albemarle, Advanced Refining Technologies
(ART), UOP, etc. Most of the new-generation catalysts possess very high activity
for hydrodesulfurization/hydrotreating with almost 2–4 times more activity compared to earlier generation catalysts. These catalysts are manufactured using novel
and proprietary methods to maximize Type II active sites to product ultralow sulfur
diesel and gasoline.
9 Conclusions
Hydrotreating/hydrodesulfurization of petroleum fractions is the mainstay in the
refining industry in order to produce environmentally benign fuels and lubricating
oils as mandated by several countries. Improvements in the catalyst activity occurred
severalfold during the last 2–3 decades due to several factors such as advanced catalyst characterization tools, improved preparation methods to increase the metal dispersion, and use of additives/modifiers during catalyst preparation in order to tune
the metal–support interactions. Some of these tools and methods helped the scientists to overcome the limitations on catalyst activity and improve the stability simultaneously. Much work has also been done in understanding the other aspects of
catalysis such as catalyst activation, deactivation, and regeneration/rejuvenation in
order to obtain the maximum activity out of HDT/HDS catalysts. Also, it is preferable to use a proper choice of a catalyst system for a particular hydrocarbon feedstock in order to achieve optimum levels of desulfurization, denitrification, and
aromatic saturation.
Acknowledgments The authors thank the management of Hindustan Petroleum Corporation
Limited, Green R&D Center, Bengaluru, for allowing them to publish this chapter.
References
1. Scherzer J, Gruia AJ (1996) Hydrocracking science and technology. Marcel Dekker, Inc.,
New York, NY, p 44
2. Stanislaus A, Marafi A, Rana MS (2010) Recent advances in the science and technology of
ultra low sulfur diesel (ULSD) production. Catal Today 153:1–68
3. Topsoe H, Clausen BS, Massoth FE (1996) In: Anderson JR, Boudart M (eds) Hydrotreating
catalysis – science and technology, vol 11. Berlin, Springer
4. Tong-na ZHOU, Hai-liang YIN, Shu-na HAN, Yong-ming CHAI, Yun-qi LIU, Chen-guang
LIU (2009) Influences of different phosphorus contents on NiMoP/Al 2 O 3 hydrotreating catalysts. J Fuel Chem Technol 37(3):330–334
5. Sun M, Nicosia D, Prins R (2003) The effect of fluorine, phosphate and chelating agents on
hydrotreating catalysts and catalysis. Catal Today 86:173–189
G. Valavarasu and B. Ramachandrarao
environment, precious metal-type catalysts (e.g., Pt or Pd) are also used as the
second- stage catalyst, especially in diesel HDT units for improvement of cetane
number. Some of the catalyst suppliers who offer HDT/HDS catalysts include
Haldor Topsoe, Axens (IFP), Criterion, Albemarle, Advanced Refining Technologies
(ART), UOP, etc. Most of the new-generation catalysts possess very high activity
for hydrodesulfurization/hydrotreating with almost 2–4 times more activity compared to earlier generation catalysts. These catalysts are manufactured using novel
and proprietary methods to maximize Type II active sites to product ultralow sulfur
diesel and gasoline.
9 Conclusions
Hydrotreating/hydrodesulfurization of petroleum fractions is the mainstay in the
refining industry in order to produce environmentally benign fuels and lubricating
oils as mandated by several countries. Improvements in the catalyst activity occurred
severalfold during the last 2–3 decades due to several factors such as advanced catalyst characterization tools, improved preparation methods to increase the metal dispersion, and use of additives/modifiers during catalyst preparation in order to tune
the metal–support interactions. Some of these tools and methods helped the scientists to overcome the limitations on catalyst activity and improve the stability simultaneously. Much work has also been done in understanding the other aspects of
catalysis such as catalyst activation, deactivation, and regeneration/rejuvenation in
order to obtain the maximum activity out of HDT/HDS catalysts. Also, it is preferable to use a proper choice of a catalyst system for a particular hydrocarbon feedstock in order to achieve optimum levels of desulfurization, denitrification, and
aromatic saturation.
Acknowledgments The authors thank the management of Hindustan Petroleum Corporation
Limited, Green R&D Center, Bengaluru, for allowing them to publish this chapter.
References
1. Scherzer J, Gruia AJ (1996) Hydrocracking science and technology. Marcel Dekker, Inc.,
New York, NY, p 44
2. Stanislaus A, Marafi A, Rana MS (2010) Recent advances in the science and technology of
ultra low sulfur diesel (ULSD) production. Catal Today 153:1–68
3. Topsoe H, Clausen BS, Massoth FE (1996) In: Anderson JR, Boudart M (eds) Hydrotreating
catalysis – science and technology, vol 11. Berlin, Springer
4. Tong-na ZHOU, Hai-liang YIN, Shu-na HAN, Yong-ming CHAI, Yun-qi LIU, Chen-guang
LIU (2009) Influences of different phosphorus contents on NiMoP/Al 2 O 3 hydrotreating catalysts. J Fuel Chem Technol 37(3):330–334
5. Sun M, Nicosia D, Prins R (2003) The effect of fluorine, phosphate and chelating agents on
hydrotreating catalysts and catalysis. Catal Today 86:173–189
G. Valavarasu and B. Ramachandrarao