Spent lube re-refining is hard on the hydrotreating catalyst and requires well-designed guardbeds


Spent lube re-refining has been around for a number of years and new plants are spreading around the world. The process converts a waste lube oil into recovered base oil stock for producing new lubricants.  The re-refining process has a much lower carbon footprint as compared to production of lubes from crude oil. Unfortunately, the spent lubes contain a number of contaminants such as Si, P, Ca, and Zn and as they can not be removed completely during the pre-treatment, they enter the hydrotreating reactor where they gradually poison the catalyst and cause pressure drop. By carefully studying where the contaminants deposit in the catalyst we can propose loading diagrams that will provide for high contaminant pick-up capacity and thereby allow longer production runs between catalyst change-outs. Next to the loading diagram the design of the distribution tray is also very important. By helping a number of lube re-refiners Catalyst Intelligence has gathered a wide experience with spent catalyst characterization and the design of loading diagrams.