Proposal of an FTIR Methodology to Monitor Oxidation Level in Used Engine Oils: Effects of Thermal Degradation and Fuel Dilution

Abstract

This paper describes a particular procedure, based on ASTM D7214 and ASTM E 2412, which has been defined to improve oil oxidation quantification in used engine oils. Taking into account typical problems that can be found in this type of samples, thermal oxidation and fuel dilution, response on FT-IR spectra has been analyzed considering also the effect of oil formulation. Two special zones have been considered inside the typical wave number range for oxidation quantification, where those problems can be detected and assessed more easily. Zone A between 1,725 cm , where esters as main products for detection of fuel dilution problems when diesel engine is operating with biodiesel.

Thermal Stability and Lubrication Properties of Biodegradable Castor Oil on AISI 4140 Steel

“…This phenomenon occurs when a lubricant oil is exposed to elevated temperatures, pressures, and oxygen from the air. The oil's hydrocarbons react with oxygen and form various compounds such as esters, ketones, aldehydes, and carbonated and carboxylic acids, the majority of which present signals within the carbonyl group (C=O) [13,14]. At this point, Fourier transform infrared spectroscopy (FTIR) is a technique which is well known for its exceptional ability to qualitatively and quantitatively analyize chemical compounds [15].…”

Terahertz Time Domain Spectroscopy to Detect Different Oxidation Levels of Diesel Engine Oil

“…Alternative methods of measuring oxidation resistance of engine oil have been studied as precursors to a real-time sensor system. These include custom sensors [11][12][13][14][15][16][17][18][19][20] and spectrometers [2,21,22]. Terahertz (THz; 100 GHz to 10 THz) is a more recent spectroscopy advancement that uses terahertz waves with amplitude measured in the time domain for the desired sample and an empty sample holder (reference).…”

“…Oxidation is the interaction between oxygen and hydrocarbons, which depends on operating conditions and oxidation resistance of the oil [1]. The oxidation process generates harmful acids in engine oil [1][2][3][4]. Oil additives of antioxidants and detergents are critical to counteract oxidation.…”

Determination of the total acid number (TAN) of used mineral oils in aviation engines by FTIR using regression models

“…In recent years, efforts have been made to replace analytical methods based on the FTIR technique. In order to obtain analytical information in a rapid, non-destructive way, mid-infrared spectroscopy has been largely applied to study motor oils for different purposes: quantifying contaminants [4] [5] , or oxidation process [6] [7] , adulteration [8] [9] [10] , determining the antioxidant concentration [11] , determining physicochemical values (TAN [8] [12] [13] , VI [14] [15] and TBN [12] [14] ), and classifying them according to their origins [16] .…”