Process for treating used lubricating oils comprising esters

Abstract

This disclosure relates to the treatment of used lubricants and / or coolants. Specifically, this disclosure concerns a method for treating used lubricants and / or coolants containing esters to improve their recyclability.

Claims

Demands

1. A process for treating a lubricating and / or cooling composition comprising at least one ester and at least one free organic acid, said process comprising a step of treating said composition with at least one base having a pKb between 2 and 6.

2. A method according to claim 1 characterized in that the base is selected from carbonates, preferably from sodium carbonate, potassium carbonate, cesium carbonate, rubidium carbonate, and mixtures thereof, and more preferably, the base is sodium carbonate.

3. A process according to any one of the preceding claims characterized in that the amount of base used is between 2 and 40% by weight relative to the weight of the lubricating and / or cooling composition to be treated.

4. A process according to any one of the preceding claims characterized in that the process is carried out at a temperature between 20 and 180°C, preferably between 60°C and 170°C.

5. A process according to any one of the preceding claims characterized in that the lubricating and / or cooling composition to be treated comprises at least 0.001% by weight of free organic acid relative to the total weight of the composition, preferably at least 0.1% and preferably between 0.1 and 3%.

6. A process according to any one of the preceding claims, characterized in that the esters contained in the lubricating and / or cooling composition to be treated are selected from: - aliphatic acid esters, wherein the aliphatic acid residue comprises a hydrocarbon chain having, preferably, from 3 to 36 carbon atoms and one or two acid functions; - polyol esters, preferably glycerol, trimethylolpropane, or neopentyl glycol esters; - unsaturated fatty acid polyesters containing up to 6 acid units; and - mixtures thereof.

7. A process according to any one of the preceding claims, characterized in that the ester content in the lubricating and / or cooling composition to be treated is at least 0.1% by weight relative to to the total weight of the composition, preferably the ester content is between 0.5 and 99%, preferably between 1 and 40%, and more preferably between 3 and 30%.

8. A process according to any one of the preceding claims characterized in that the lubricating and / or cooling oil to be treated comprises at least 30% by weight of at least one base oil of mineral or synthetic origin belonging to groups I to IV, preferably at least 60%.

9. A method according to any one of the preceding claims characterized in that the lubricating and / or cooling composition to be treated is a used lubricating and / or cooling composition.

10. A process according to any one of the preceding claims characterized in that it comprises at least one treatment step of the lubricating oil obtained after treatment selected from dehydration, distillation, filtration, liquid / liquid extraction, decantation, passage over an adsorbent material and transesterification.

11. Use of the process according to any one of the preceding claims to improve the eco-performance of lubricating and / or cooling compositions comprising esters, the eco-performance preferably being characterized by: - ​​minimizing the carbon footprint of lubricating and / or cooling compositions comprising esters, - improving the recyclability of lubricating and / or cooling compositions comprising esters, - increasing the content of bio-based compounds in lubricating and / or cooling compositions, and / or - reducing the use of fossil resources.