Patent EA-000717-B1 (EA)
Title: Process for the preparation of lubricating base oils
Inventor: MOUREAUX PATRICK
IPC: B01J27/19
Filed: 1997-07-04
Abstract: 1. Process for the preparation of lubricating base oils having a viscosity index of at least 80 comprising the steps of (a) contacting a hydrocarbon oil feed comprising to 3 wt % sulfur-containg and to 1 wt % nitrogen-containing compounds in the presence of hydrogen in a first reaction zone with a catalyst comprising at least one Group VIB metal component and at least one cobalt or nickel metal component supported on a refractory oxide carrier; (b) separating the effluent at elevated pressure into a gaseous fraction and a liquid fraction; (c) contacting the liquid fraction in the presence of hydrogen in a second reaction zone comprising two separate catalyst beds, whereby the upper catalyst bed comprises a noble metal-based catalyst selective for hydroisomerising and/or hydrocracking of waxy molecules and the lower catalyst bed comprises the catalyst comprising at least Process according to claims 1-5, wherein the upper catalyst bed at step (c) comprises (d) recovering a lubricating base oil; wherein step (a) is operated at a temperature of at least 350 degree C obtaining the liquid fraction after step (b) having a sulphur content of less than 1000 ppmw and a nitrogen content of less than 50 ppmw, and the temperature of the lower catalyst bed at step (c) is lower than the temperature of the upper catalyst bed, and the catalyst comprising  noble metal component comprises platinum and/or palladium supported on an amorphous silica-alumina carrier. 2. Process according to claim 1, wherein the first reaction zone is operated at a temperature is in the range f from 365 to 500 degree C, more preferably from 375 to 450 degree C. 3. Process according to claims 1-2, wherein the temperature in the upper catalyst bed is in the range of from 250 to 350 degree C. 4. Process according to claims 1-3, wherein the temperature in the lower catalyst bed is in the range of from 200 to 300 degree C. 5. Process according to claims 1-4, wherein the catalyst in the first reaction zone comprises nickel and/or cobalt as a non noble metal component in amount from 1 to 25 wt % and molybdenum and/or tungsten as a Group VIB metal component in amount from 5 to 30 wt %, calculated as element mass ratio to the total catalyst mass. 6. Process according to claims 1-5, wherein the upper catalyst bed at step (c) comprises a platinum component supported on an amorphous silica-alumina carrier. 7. Process according to claim 1, wherein the amorphous silica-alumina carrier is a carrier supported on the amorphous zeolitic material ZSM-5. 8. Process according to claims 1-7, wherein the lower catalyst bed at step (c) comprises a catalyst comprising, at least, one noble Group VIII metal component supported on an amorphous refractory oxide carrier as the single catalyst. 9. Process according to claims 1-8, wherein the lower catalyst bed at step (c) comprises a catalyst comprising platinum and/or palladium supported on an amorphous silica-alumina carrier. 10. Process according to claims 1-9, wherein the upper catalyst bed and the lower catalyst bed at step (c) are separated by an instantaneous cooling. 11. Process according to claims 1-10 wherein the temperature in the reactor for the lower catalyst bed is changed periodically in the interval from 200 to 300 degree C to obtain different lubricating base oils, which meet certain requirements towards the content of aromatic compounds. 12. Process according to claims 1-11 wherein a gaseous fraction obtained at step (c) is treated to remove ammonia and/or hydrogen sulphide after which the cleaned gas is recycled to the first reaction zone. 13. Process according to claims 1-12 wherein step (d) involves fractionation of the effluent from step (c) to obtain a gaseous fraction and at least one liquid fraction as the lubricating base oil product, wherein the gaseous fraction is treated to remove impurities, after which the cleaned gas is recycled to the first reaction zone wherein the second reaction zone is supplied with only fresh hydrogen. 14. Process according to claim 13 wherein the treatment of the gaseous fractions takes place in the same gas cleaning unit.