Hydrofinishing catalyst and method for producing base oil using same
A hydrofinishing catalyst according to the present invention includes an amorphous silica-alumina support; and a hydrogenated active metal supported on the support, and has an Al composition having a total mass (wt %) of Al and Si as a denominator and a mass (wt %) of Al as a numerator with respect to a reference line, which is a straight line passing through the center of a cross-section of the support, locations evenly spaced apart along the reference line are sequentially numbered, where composition uniformity, which is defined as UN by the Al composition at the i-th location and an average Al composition at the cross-section of the support passing through the center of the support, is 3.0 or less.
1. A hydrofinishing catalyst comprising:
an amorphous silica-alumina support; and
a hydrogenated active metal supported on the support,
wherein composition uniformity defined as the following Expression 1 satisfies Expression 2,
UN
=
∑
i
=
1
i
=
M
C
Al
(
i
)
-
C
Al
(
ave
)
M
×
C
Al
(
ave
)
×
1
0
0
(
Expression
1
)
in Expression 1, UN is composition uniformity, C Al is an Al composition having a total mass (wt %) of Al and Si as a denominator and a mass (wt %) of Al as a numerator, C Al (ave) is an average Al composition on a cross section of a support passing through the center of the support, C Al (i) is an Al composition at an i-th position of positions spaced apart from each other by a predetermined interval along a reference line and sequentially numbered, the reference line being a straight line passing through the center of the cross section of the support, and M is a total number of positions at which the Al composition is measured at the reference line, and is a natural number of 20 to 500,
UN≤ 3.0, and (Expression 2)
The catalyst satisfies the following Expression 4
(Expression 4)
Amount of Bronsted acid sites measured by adsorption of pyridine at 200° C.≥30 μmol/g.
2. The hydrofinishing catalyst of claim 1 , wherein the catalyst satisfies the following Expression 3,
5.00≤ Pv (100−500)/ Pv (10−500)*100 (Expression 3)
in Expression 3, Pv(10−500) is a total volume (cm 3 /g) of pores within a size range of 10 to 500 nm per unit mass of the catalyst, and Pv(100−500) is a total volume (cm 3 /g) of pores within a size range of 100 to 500 nm per unit mass of the catalyst.
3. The hydrofinishing catalyst of claim 1 , wherein the catalyst has a strength of a Bronsted acid site satisfying the following Expression 5, Expression 6, or Expressions 5 and 6,
(Expression 5)
Amount of Bronsted acid sites measured by adsorption of pyridine at 300° C.≥25 μmol/g,
(Expression 6)
Amount of Bronsted acid sites measured by adsorption of pyridine at 400° C.≥10 μmol/g.
4. The hydrofinishing catalyst of claim 1 , wherein the active metal is one or two or more metals belonging to Groups VI to VIII.
5. The hydrofinishing catalyst of claim 4 , wherein the active metal contains Pd, Pt, or Pd and Pt.
6. The hydrofinishing catalyst of claim 4 , wherein the catalyst contains a first active metal and a second active metal, and a weight ratio of the first active metal to the second active metal is 1.0:0.1 to 1.0.
7. The hydrofinishing catalyst of claim 1 , wherein the catalyst contains 0.1 to 5 wt % of the active metal.
8. A method for producing base oil, comprising:
a step of dewaxing raw oil for producing base oil in the presence of an isomerization catalyst to obtain a catalytic dewaxed oil fraction; and
a step of hydrofinishing the catalytic dewaxed oil fraction using the hydrofinishing catalyst of claim 1 to produce base oil.