Method for producing high quality base oils using multiple stage processing

Abstract

Described are processes to produce base oils with one more improved properties, e.g., lower aromatics, economically and / or efficiently. In some embodiments the processes comprise a step that reduces the amount of residual refractory sulfur compounds prior to or simultaneous with a hydrofinishing step which advantageously provides base oils with lower aromatics than comparable processes.

Description

FIELD OF THE INVENTION[0001]The present disclosure relates to methods for producing high quality base oils using, for example, novel methods comprising a step for reducing the amount of residual refractory sulfur compounds prior to or simultaneous with a hydroprocessing step.BACKGROUND AND SUMMARY[0002]Modern refining processes for producing lubricating oils from crudes typically use a number of hydrogen processes. The processes are employed to produce lubricating oils having suitable lubricating properties over a wide range of operating conditions. Hydrotreating / hydrocracking is generally an upgrading process for increasing viscosity index by removing low viscosity index molecules, including molecules containing sulfur and nitrogen. Hydrodewaxing is typically a process for improving the low temperature properties by isomerizing the long chain waxy molecules, if otherwise not removed, may have a negative impact on the pour and cloud points of the fractions. Hydrofinishing typically ...

AI Technical Summary

Benefits of technology

The patent text describes a process to improve the conversion of aromatics in a petroleum feed. By adding a hydrofinishing stage and then a stage with a base metal catalyst, the conversion of aromatics increased from 86.8% to 99.2%. The text also suggests that the performance of the catalyst can be improved by layering it in specific zones. These results demonstrate that the process can be effective in upgrading the quality of petroleum feed.

Problems solved by technology

Hydrodewaxing is typically a process for improving the low temperature properties by isomerizing the long chain waxy molecules, if otherwise not removed, may have a negative impact on the pour and cloud points of the fractions.

However, in many cases the base oil still may have undesirable levels of aromatics, residual organic sulfur, and / or nitrogen.

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