Fresh Feed Rate (LHSV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Liquid Recycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Hydrogen Partial Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Recycle Gas Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Makeup Hydrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Hydrogen Purity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Nitrogen and Methane Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
CO + CO 2 Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Commercial Suppliers of Hydrocracking Process and Catalyst Technology . . . . . . . . . . . . . . . . . 357
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Abstract
Hydrocracking is a flexible catalytic refining process that can upgrade a large
variety of petroleum fractions. Hydrocracking is commonly applied to
upgrade the heavier fractions obtained from the distillation of crude oils,
including residue. The process adds hydrogen which improves the hydrogen
to carbon ratio of the net reactor effluent, removes impurities like sulfur to
produce a product that meets the environmental specifications, and converts
the heavy feed to a desired boiling range. The chemistry involves the conversion of heavy molecular weight compounds to lower molecular weight compounds through carbon-carbon bond breaking and hydrogen addition. The
main products have lower boiling points, are highly saturated, and generally
range from heavy diesel to light naphtha. Hydrocracking processes are
designed for, and run at, a variety of conditions. The process design will
depend on many factors such as feed type, desired cycle length, and the
desired product slate. Hydrocracking is a process that is suitable to produce
products that meet or exceed all of the present environmental regulations.
Hydrocracking reactions proceed through a bifunctional mechanism.
Two distinct types of catalytic sites are required to catalyze the steps in the
reaction sequence. The cracking and isomerization reactions take place on the
acidic support. The acid can be an amorphous silica alumina or a zeolite.
The metals provide the hydrogenation function. The metals are typically noble
metal (palladium, platinum) or non-noble metal sulfides from group VIA
(molybdenum, tungsten) and group VIIA (cobalt, nickel).
Catalyst manufacturing can be done by a variety of methods. The method
chosen represents a balance between the manufacturing cost and the degree to
which the desired chemical and physical properties are achieved. Many companies are involved in the licensing of the process and the production of a variety of
hydrocracking catalysts.
Keywords
Hydrocracking • Hydroprocessing • zeolite • Y zeolite • Beta zeolite • Ni, W • Pt
base metals • Base metal sulfide • Noble metal • Single stage • Two stage •
Vacuum gas oil (VGO) • Unconverted oil (UCO) • Diesel • Distillate • Gasoline •
Cracking • Isomerization • Hydrogenation • Aromatic saturation •
318
M. Bricker et al.
Liquid Recycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Hydrogen Partial Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Recycle Gas Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Makeup Hydrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Hydrogen Purity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Nitrogen and Methane Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
CO + CO 2 Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Commercial Suppliers of Hydrocracking Process and Catalyst Technology . . . . . . . . . . . . . . . . . 357
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Abstract
Hydrocracking is a flexible catalytic refining process that can upgrade a large
variety of petroleum fractions. Hydrocracking is commonly applied to
upgrade the heavier fractions obtained from the distillation of crude oils,
including residue. The process adds hydrogen which improves the hydrogen
to carbon ratio of the net reactor effluent, removes impurities like sulfur to
produce a product that meets the environmental specifications, and converts
the heavy feed to a desired boiling range. The chemistry involves the conversion of heavy molecular weight compounds to lower molecular weight compounds through carbon-carbon bond breaking and hydrogen addition. The
main products have lower boiling points, are highly saturated, and generally
range from heavy diesel to light naphtha. Hydrocracking processes are
designed for, and run at, a variety of conditions. The process design will
depend on many factors such as feed type, desired cycle length, and the
desired product slate. Hydrocracking is a process that is suitable to produce
products that meet or exceed all of the present environmental regulations.
Hydrocracking reactions proceed through a bifunctional mechanism.
Two distinct types of catalytic sites are required to catalyze the steps in the
reaction sequence. The cracking and isomerization reactions take place on the
acidic support. The acid can be an amorphous silica alumina or a zeolite.
The metals provide the hydrogenation function. The metals are typically noble
metal (palladium, platinum) or non-noble metal sulfides from group VIA
(molybdenum, tungsten) and group VIIA (cobalt, nickel).
Catalyst manufacturing can be done by a variety of methods. The method
chosen represents a balance between the manufacturing cost and the degree to
which the desired chemical and physical properties are achieved. Many companies are involved in the licensing of the process and the production of a variety of
hydrocracking catalysts.
Keywords
Hydrocracking • Hydroprocessing • zeolite • Y zeolite • Beta zeolite • Ni, W • Pt
base metals • Base metal sulfide • Noble metal • Single stage • Two stage •
Vacuum gas oil (VGO) • Unconverted oil (UCO) • Diesel • Distillate • Gasoline •
Cracking • Isomerization • Hydrogenation • Aromatic saturation •
318
M. Bricker et al.