36
the choice of active metals and support material, additives also play a significant
role in modifying the catalyst and enhancing its performance. Proper catalyst preparation method needs to be considered while designing a hydrotreating catalyst in
order to obtain the required composition and properties. Since the choice of additives and preparation methods is of paramount importance for the design of successful hydrotreating catalysts, it is essential to delve into the advances in these areas. It
is also essential to understand the activation/sulfidation, deactivation, and regeneration of HDT/HDS catalysts in order to obtain a complete understanding of
hydrotreating catalysts. The present chapter focuses mainly on the catalytic advancements in the area of hydrotreating/hydrodesulfurization of petroleum fractions in
terms of additives, catalyst preparation methods, catalyst activation, deactivation
and regeneration, and catalyst selection for different feedstocks.
2 Preparation of Hydrotreating Catalysts
Hydrotreating catalysts are usually prepared by a variety of manufacturing methods.
A complex relationship exists between catalyst formulation, preparation method,
and catalyst properties in the case of hydrotreating catalysts. Chemical composition
also plays a major role in determining the performance of industrial hydrotreating
catalysts such as content of active metals and concentration of promoters and additives. Nevertheless, physical and mechanical properties of the catalysts are also
important to overcome the diffusional limitations of hydrocarbon molecules, particle attrition due to poor mechanical strength, and pressure drop issues. Preparation
of supported metal catalysts used in industrial hydrotreating and hydrocracking
units usually involves the following steps [1]:
– Precipitation.
– Filtration (decantation, centrifugation).
– Washing.
– Drying.
– Forming.
– Calcining.
– Impregnation of active metals.
– Activation/sulfidation.
Some of the additional steps such as kneading, mulling, grinding, and sieving
may also be used along with the above methods depending upon the specific requirement. Scherzer and Gruia [1] provide a detailed account of catalyst preparation and
manufacturing methods for hydroprocessing catalysts.
G. Valavarasu and B. Ramachandrarao
the choice of active metals and support material, additives also play a significant
role in modifying the catalyst and enhancing its performance. Proper catalyst preparation method needs to be considered while designing a hydrotreating catalyst in
order to obtain the required composition and properties. Since the choice of additives and preparation methods is of paramount importance for the design of successful hydrotreating catalysts, it is essential to delve into the advances in these areas. It
is also essential to understand the activation/sulfidation, deactivation, and regeneration of HDT/HDS catalysts in order to obtain a complete understanding of
hydrotreating catalysts. The present chapter focuses mainly on the catalytic advancements in the area of hydrotreating/hydrodesulfurization of petroleum fractions in
terms of additives, catalyst preparation methods, catalyst activation, deactivation
and regeneration, and catalyst selection for different feedstocks.
2 Preparation of Hydrotreating Catalysts
Hydrotreating catalysts are usually prepared by a variety of manufacturing methods.
A complex relationship exists between catalyst formulation, preparation method,
and catalyst properties in the case of hydrotreating catalysts. Chemical composition
also plays a major role in determining the performance of industrial hydrotreating
catalysts such as content of active metals and concentration of promoters and additives. Nevertheless, physical and mechanical properties of the catalysts are also
important to overcome the diffusional limitations of hydrocarbon molecules, particle attrition due to poor mechanical strength, and pressure drop issues. Preparation
of supported metal catalysts used in industrial hydrotreating and hydrocracking
units usually involves the following steps [1]:
– Precipitation.
– Filtration (decantation, centrifugation).
– Washing.
– Drying.
– Forming.
– Calcining.
– Impregnation of active metals.
– Activation/sulfidation.
Some of the additional steps such as kneading, mulling, grinding, and sieving
may also be used along with the above methods depending upon the specific requirement. Scherzer and Gruia [1] provide a detailed account of catalyst preparation and
manufacturing methods for hydroprocessing catalysts.
G. Valavarasu and B. Ramachandrarao