the higher values showing operating conditions used for hydrotreating atmospheric resids. Until about 1980, hydrotreating was a licensed technology being
offered by a fairly large number of companies. From 1980 until the end of the last
century, hydrotreating catalysts were becoming more commoditized as the formulations were less differentiated among the various suppliers. With the advent
of ultra-low-sulfur fuel regulations ushering in the first decade of the twenty-first
century, however, it was required for hydrotreating research and development to
deliver quantum improvements in catalyst performance and process technology.
This was accomplished in the form of so-called Type II supported transition metal
sulfide (TMS) catalysts, unsupported/bulk TMS catalysts, improved bed grading
catalysts and stacking strategies, advanced catalyst loading techniques, improved
trickle-flow reactor internals designs, and more effective catalyst activation
methodologies.
The common objectives and applications of hydrotreating are listed below:
• Straight-run and coker naphtha (catalytic reformer feed pretreatment) – to
remove sulfur, nitrogen, and contaminants (e.g., Si) that otherwise would poison
downstream, noble metal reforming catalysts
• Pyrolysis gasoline and coke-oven light oil – to remove sulfur and nitrogen and to
hydrogenate di-unsaturates that would otherwise deactivate/foul downstream
equipment and/or catalysts in the aromatics complex
• LPG – to remove sulfur and nitrogen and to hydrogenate di-unsaturates
that would otherwise deactivate downstream, noble metal dehydrogenation
catalysts
• Kerosene and diesel – to remove sulfur and to hydrogenate unsaturates, resulting
in improved properties of the streams (kerosene smoke point, diesel cetane,
specific gravity) as well as storage stability
• Shale oil – to remove sulfur, nitrogen, arsenic, and oxygen, resulting in improved
properties of the streams as above
• Lube oil – to improve the viscosity index, color, and stability as well as storage
stability
• Used lube oil – to remove contaminants and blending package additives, which,
for example, may contain zinc and phosphorus, and to at least restore the quality
to that of the original base oil
• Vegetable oils and animal tallows – to remove contaminants and to complete one
step in the conversion of triglycerides to jet, kerosene, and diesel fuels
• FCC feed – to improve FCC yields especially of gasoline and propylene, to
improve the quality of the gasoline and the diesel/light cycle oil, and to reduce
catalyst usage and stack emissions
• Hydrocracking – to maximize the yield of ultra-low-sulfur diesel (ULSD) and to
improve the properties of hydrocracked fuels (naphtha sulfur and nitrogen,
kerosene smoke point, diesel cetane, specific gravity)
• Atmospheric and vacuum residua – to provide low-sulfur, low-metal fuel oils to
effect conversion and/or pretreatment for further conversion downstream
364
P. Kokayeff et al.
offered by a fairly large number of companies. From 1980 until the end of the last
century, hydrotreating catalysts were becoming more commoditized as the formulations were less differentiated among the various suppliers. With the advent
of ultra-low-sulfur fuel regulations ushering in the first decade of the twenty-first
century, however, it was required for hydrotreating research and development to
deliver quantum improvements in catalyst performance and process technology.
This was accomplished in the form of so-called Type II supported transition metal
sulfide (TMS) catalysts, unsupported/bulk TMS catalysts, improved bed grading
catalysts and stacking strategies, advanced catalyst loading techniques, improved
trickle-flow reactor internals designs, and more effective catalyst activation
methodologies.
The common objectives and applications of hydrotreating are listed below:
• Straight-run and coker naphtha (catalytic reformer feed pretreatment) – to
remove sulfur, nitrogen, and contaminants (e.g., Si) that otherwise would poison
downstream, noble metal reforming catalysts
• Pyrolysis gasoline and coke-oven light oil – to remove sulfur and nitrogen and to
hydrogenate di-unsaturates that would otherwise deactivate/foul downstream
equipment and/or catalysts in the aromatics complex
• LPG – to remove sulfur and nitrogen and to hydrogenate di-unsaturates
that would otherwise deactivate downstream, noble metal dehydrogenation
catalysts
• Kerosene and diesel – to remove sulfur and to hydrogenate unsaturates, resulting
in improved properties of the streams (kerosene smoke point, diesel cetane,
specific gravity) as well as storage stability
• Shale oil – to remove sulfur, nitrogen, arsenic, and oxygen, resulting in improved
properties of the streams as above
• Lube oil – to improve the viscosity index, color, and stability as well as storage
stability
• Used lube oil – to remove contaminants and blending package additives, which,
for example, may contain zinc and phosphorus, and to at least restore the quality
to that of the original base oil
• Vegetable oils and animal tallows – to remove contaminants and to complete one
step in the conversion of triglycerides to jet, kerosene, and diesel fuels
• FCC feed – to improve FCC yields especially of gasoline and propylene, to
improve the quality of the gasoline and the diesel/light cycle oil, and to reduce
catalyst usage and stack emissions
• Hydrocracking – to maximize the yield of ultra-low-sulfur diesel (ULSD) and to
improve the properties of hydrocracked fuels (naphtha sulfur and nitrogen,
kerosene smoke point, diesel cetane, specific gravity)
• Atmospheric and vacuum residua – to provide low-sulfur, low-metal fuel oils to
effect conversion and/or pretreatment for further conversion downstream
364
P. Kokayeff et al.