recycling rates for used base oils. The Brazilian lubricant market is a good example of how the synergy between policies, engineering, and logistics can deliver significant results to increase circularity and reduce the carbon intensity of the products. Figure 2 shows that the total lubricants
1,600,000
Lubricating oils commercialised (m ) Collected used lubricating oil (m )
1,400,000
1,200,000
1,000,000
800,000
600,000
400,000
200,000
2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 0
Figure 2 Volumes of lubricating oils sold and used oils recovered for re- refining in Brazil (2014-2023) (Brazilian Petroleum Agency (ANP), 2025)
market in Brazil was around 1.9 million m3. The combination of logistics, re-refining infrastructure, and supportive public policies has resulted in the growth of used lubricating oil recovery in Brazil, with approximately 40% now collected for re-refining. With the fourth-largest re-refining infrastructure in the world, Brazil is now a leader in the re- refining of used lubricating oil in Latin America. The re-refining of used lubes can minimise environmental risks and raise the circularity profile of the national refining industry. Threat of used lubricating oil Used lubricating oils are considered to be hazardous due to high concentrations of heavy metal contaminants, including chromium, cadmium, lead, and arsenic. Furthermore, just one litre of used lubricating oil can contaminate around one million litres of fresh water. Table 2 compares the properties of fresh and used lubricating oil. During use, lubricating oil performance decreases over time due to contamination resulting from the operating conditions of Otto cycle and diesel engines. Over time, contaminants accumulate in used lubricating oil and, unless handled carefully, can become a hazardous environmental contaminant. Lubricants production routes Lubricant production starts with vacuum distillation of atmospheric residue from the atmospheric distillation processes. In lube production refineries, fractionation in vacuum distillation units is more carefully controlled than in units solely used for the production of fuels. This is
Group
Typical production process
I
Solvent extraction
II
Hydrocracking/hydrotreating or hydrocracking + solvent extraction Hydrocracking/hydrotreating
III IV
Synthetic
Table 1 Lubricant base oils classification
Properties
Fresh Used lubricating oil lubricating oil
Specific gravity at 20 o C
0.882
0.910
Flash point, o C
220 2.20 4.70 139
190 4.40 1.70 115 14.8 0.30 12,3 0.42
Total acid number, mg KOH/g oil Total base number, mg HCl/g oil
Viscosity at 40 o C, cSt Viscosity at 100 o C, cSt Carbon residue, wt%
16
0.82
Water, vol% Sulphur, % Lead, ppm Zinc, ppm Calcium, ppm
-
0.32
0
7,535 1,097 4,468
1,664 1,210 1,397
Phosphorous, ppm Magnesium, ppm
931 309 297 205 118
675
Barium, ppm
37
Iron, ppm
3 4
Sodium, ppm
Table 2 Properties of fresh and used lubricating oils (Assuncao Filho, et al., 2010)
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