An Alternative Procedure to Quantify Soot in Engine Oil by Ultraviolet-Visible Spectroscopy

Abstract

Internal combustion engines (ICE), as a consequence of new pollutant emissions standards, need several emission control strategies (and related procedures) such as Exhaust Gases Recirculation (EGR), Diesel/Gasoline Particulate Filter (DPF/GPF), Selective Catalyst Reduction (SCR) that allow them to comply with complete requirements defined on those standards. These strategies provoke faster degradation of the engine oil and one of the most relevant consequences is an increase in soot contamination level. All of these strategies facilitate the soot generation.Consequently, soot is one of the most important contaminants present in the engine oil and its relevance is still increasing. The main and classic technique to measure the content of soot in oil is Thermogravimetric analysis (TGA), but this technique has certain limitations. TGA needs a long specific procedure and has limitations to measure small concentration of soot in oil. Therefore, the design of an alternative technique to quantifying the soot in oil concentration is acquiring relevance. One alternative can be the Fourier-transform infra-red (FTIR) spectroscopy, but it also has limitations related to small concentrations of soot in oil. This work presents an alternative technique based on the Ultraviolet-Visible (UV-Vis) spectroscopy, which will let us to quantify 2 small soot contents in used engine oil samples and avoiding potential interferences from other typical contaminants or related with the own measurement process such as sample cuvette material.

A Review on Oil-Soluble Polyisobutylene-Based Dispersant for Colloidal Stabilization

“…The utilization of UV-vis spectroscopy has been growing extensively in work on carbonaceous substances in the liquid phase. Recent research by Macián and co-workers reported that ultraviolet-visible (UV-vis) absorption spectroscopy was used as an alternative to Fourier-transform infrared spectroscopy (FTIR) [9]. UV-vis has allowed them to quantify small soot contents in the used engine oil samples and avoid potential interferences from other typical contaminants related to their measurement process.…”

UV-Visible Spectrophotometer for Distinguishing Oxidation Time of Engine Oil

“…While several regions in the infrared spectrum have been identified as related to engine oil oxidation, far fewer UV-Vis studies have been found to address the issue of oil oxidation, with many of those focusing on oxidized vegetable oils or biodiesel [40][41][42][43]. UV-Vis has also been previously evaluated as an alternative to human eye assessment of the color index of transformer oil [44] as it ages due to oxidation and as a means to quantify soot in engine oil [45]. However, a study by Chevron used a liquid chromatography system coupled with a UV-Vis detector to differentiate between base stock oils used in engine lubricants and correlated those base oils with their analysis of oxidation stability that was found by measuring the time taken to react with a given amount of oxygen in the presence of an oxidation accelerator and an inhibitor [46].…”