Patent EA-005089-B1 (EA)
Title: Process to prepare a lubricating base oil and a gas oil
Inventor: GERMAINE GILBERT ROBERT BERNAR
IPC: C10G65/04
Filed: 2002-03-04
Abstract: 1. Process to prepare a lubricating base oil and a gas oil by (a)hydrocracking/hydroisomerisating a Fischer-Tropsch product, wherein weight ratio of compounds having at least 60 or more carbon atoms and compounds having at least 30 carbon atoms in the Fischer-Tropsch product is at least 0.2 and wherein at least 30 wt% of compounds in the Fischer-Tropsch product have at least 30 carbon atoms, (b) separating the product of step (a) into one or more gas oil fractions, a base oil precursor fraction and a higher boiling fraction, and (c) performing a pour point reducing step to the base oil precursor fraction obtained in step (b). 2. Process according to claim 1, wherein at least 50 wt% of compounds in the Fischer-Tropsch product have at least 30 carbon atoms. 3. Process according to any one of claims 1-2, wherein the conversion in step (a) is between 25 and 70wt%. 4. Process according to any one of claims 1-3, wherein the base oil precursor fraction has a T10 wt% boiling point of between 200 and 450 degree C and a T90 wt% boiling point of between 400 and 550 degree C. 5. Process according to claim 4, wherein the base oil precursor fraction has a kinematic viscosity at 100 degree C of between 3 and 10 cSt. 6. Process according to any one of claims 1-5, wherein two or more base oil grades are prepared from two or more corresponding base oil precursor fractions, which base oil grades have a difference in kinematic viscosity at 100 degree C of less than 2 cSt and wherein step (b) is performed such that each base oil precursor fraction is prepared one after the other in a period of time. 7. Process according to any one of claims 1-6, wherein the base oil having the desired specifications is the directly obtained product of step (c) from which only a lower boiling fraction is removed. 8. Process according to any one of claims 1-7, wherein a base oil is prepared having a kinematic viscosity at 100 degree C of between 3.5 and 4.5, a Noack volatility lower than 14% w and a pour point of between -15 and -60 degree C by catalytic dewaxing in step (c) a base oil precursor fraction obtained in step (b) having a kinematic viscosity at 100 degree C of between 3.2 and 4.4 cSt. 9. Process according to any one of claims 1-7, wherein a base oil is prepared having a kinematic viscosity at 100 degree C of between 4.5 and 5.5, a Noack volatility lower than 10 wt% and a pour point of between -15 and -60 degree C by catalytic dewaxing in step (c) a base oil precursor fraction obtained in step (b) having a kinematic viscosity at 100 degree C of between 4.2 and 5.4 cSt. 10. Process according to any one of claims 1-6, wherein the dewaxed fraction obtained in step (c) is separated into two or more base oil grades by means of a vacuum distillation step and wherein the required volatility properties of the base oil grades are met by also separating a fraction boiling just below at least one of said grades. 11. Process according to claim 10, wherein the vacuum distillation step is performed in a vacuum distillation column provided with side strippers. 12. Process according to any one of claims 1-11, wherein part or all of the higher boiling fraction obtained in step (b) is recycled to step (a). 13. Process according to any one of claims 1-12, wherein the catalytic dewaxing in step (c) is performed in the presence of a catalyst comprising a Group VIII metal, an intermediate pore size zeolite having pore diameter between 0.35 and 0.8 nm, and a low acidity refractory binder which binder is essentially free of alumina. 14. Process according to any one of claims 1-13, wherein a Fischer-Tropsch reaction product used in step (a) has an boiling point below 200 degree C. 15. Process according to any one of claims 1-14, wherein the catalyst used in step (a) comprises platinum, applied on silica-alumina support.