literature is notably scant on the multitude of complex chemical reactions that occur during re-refining.
It should be noted that cold solvent extraction using liquid propane is another option to remove contaminants, while some high pressure hydrotreatment processes can complete a number of reactions in one step, whereas other processes require several.
One important aim of processing is to ensure any polycyclic aromatic hydrocarbons (PAHs) introduced during the lubricants use, from partly combusted fuels, are removed to meet requisite toxicological standards including the IP346 test of 3% specified PAH’s max.
For general guidance, the yield from a range of re-refining processes on dry feedstock is typically around 70% base oils, where the viscosity outputs are largely dependent on the feedstock type and fractionation set up, 10% light fuel of a gas oil type, and the remaining balance comprised of a heavy residue, often used in asphalt or bitumen products as an alternative flux oil.
A detailed account of the quality and environmental benefits of re-refining ULOs to obtain base oils and other streams will be included in articles three and
four of this series, but here it is highlighted that on a well to wheel basis, carbon savings form a large part of the re-refining sustainability feature. With the range of re-refining treatments available to quote a single carbon life cycle figure would be inappropriate, but studies to ISO 14040/14044 guidelines show considerable savings ranging from 364-549 kg CO2
-eq./t of waste oil.
The key message is that re-refiners have mastered the processing experience of traditional base oil refining to manage the removal from used oils of a different range of unwanted contaminants, compared with those in crude oils, without detracting from the market requirement to provide base oils of the character originally described by the globally recognised API Group classifications. They do so in a sustainable manner with large carbon savings relative to that of other energy recovery options.
This article was produced by Slicker Recycling Limited and its joint venture partner, Avista Green.
www.slickerrecycling.com
avistagreen.dk
LUBE MAGAZINE NO.177 OCTOBER 2023
13
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
