Method for producing lubricating-oil base oil
View Patent ↗A method for producing a lubricant base oil which comprises a first step of carrying out isomerization dewaxing by contacting, in the presence of hydrogen, a hydrocarbon oil containing normal paraffin having a boiling point of 360° C. or higher, with a hydroisomerization catalyst under conditions such that a cracking rate defined in the following formula (1) is 10 mass % or less, and a second step of carrying out the above isomerization dewaxing by temporarily switching the above conditions to conditions such that the cracking rate is 13 mass % or more. Cracking rate (mass %)=[( C 1 −C 2 )/ C 1 ]×100 (1) wherein C 1 represents the mass ratio of a fraction having a boiling point of 360° C. or higher in the above hydrocarbon oil, and C 2 represents the mass ratio of the fraction having a boiling point of 360° C. or higher in the above hydrocarbon oil after the isomerization dewaxing.
1. A method for producing a lubricant base oil, comprising:
a first step of carrying out isomerization dewaxing by contacting, in the presence of hydrogen, a hydrocarbon oil containing normal paraffin having a boiling point of 360° C. or higher, with a hydroisomerization catalyst under conditions such that a cracking rate defined in the following formula (1) is 10 mass % or less; and
a second step of carrying out the isomerization dewaxing by temporarily switching the conditions to conditions such that the cracking rate is 13 mass % or more,
Cracking rate(mass %)=[( C 1 −C 2 )/ C 1 ]×100 (1)
wherein C 1 represents a mass ratio of a fraction having a boiling point of 360° C. or higher in the hydrocarbon oil, and C 2 represents the mass ratio of the fraction having a boiling point of 360° C. or higher in the hydrocarbon oil after the isomerization dewaxing.
2. The method for producing a lubricant base oil according to claim 1 , wherein
the hydroisomerization catalyst is a catalyst containing a zeolite having a one-dimensional porous structure including a 10-membered ring, a support containing a binder, and platinum and/or palladium supported on the support;
a carbon content of the catalyst is 0.4 to 3.5% by mass;
the zeolite is derived from an ion-exchanged zeolite obtained by ion-exchanging an organic template-containing zeolite containing an organic template and having a one-dimensional porous structure including a 10-membered ring in a solution containing ammonium ions and/or protons.
3. The method for producing a lubricant base oil according to claim 1 , wherein
the hydroisomerization catalyst is a catalyst containing a zeolite having a one-dimensional porous structure including a 10-membered ring, a support containing a binder, and platinum and/or palladium supported on the support;
a micropore volume per unit mass of the catalyst is 0.02 to 0.12 cc/g;
the zeolite is derived from an ion-exchanged zeolite obtained by ion-exchanging an organic template-containing zeolite containing an organic template and having a one-dimensional porous structure including a 10-membered ring in a solution containing ammonium ions and/or protons; and
a micropore volume per unit mass of the zeolite contained in the catalyst is 0.01 to 0.12 cc/g.
4. The method for producing a lubricant base oil according to claim 1 , wherein while performing the first step continuously, the second step is temporarily carried out at predetermined intervals.