Determination of the oxidative stability of biodiesel fuels by near-infrared spectroscopy. (15th April 2021)

• Record Type: Journal Article
• Authors: Varghese, Gelu; Saeed, Khizer; Rutt, Ken J.
• Is Part Of: Fuel. Volume 290(2021)
• Publication Date: 2021-04-15
• Subjects: Biofuels -- Peroxide values -- P-anisidine values -- Conjugated diene values -- Rancimat -- Values -- Viscosity -- NIR OSI; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2020.120015
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Near Infrared Spectroscopy (NIR) is implemented to determine the oxidative stability of biodiesel fuel. A new calibration model is developed based on nine different biodiesel fuels. NIR based technique gives fast measurements (in less than 60 s) of the oxidative stability of biodiesel fuels. NIR technique is fully validated against the well known values of all the oxidative properties. Abstract: In this work, Near Infrared Spectroscopy (NIRS) has been developed as a technique for the rapid measurements of the oxidative stability of biodiesel fuels. Firstly, use of near-infrared spectroscopy for rapid determination of the oxidation level in biodiesel, a new calibration model was developed based on nine different biodiesel oxidation properties: conjugated diene value (CD), P-anisidine value (P-AV), Peroxide value (PV), Viscosity at 40 °C and 100 °C, Iodine Value (IV), Bis Allylic Position Equivalent (BAPE), Degree of Unsaturation factor, and values of the oxidative stability Index (OSI). Partial least squares regression and forward stepwise multiple linear regressions were used to quantify the spectral data with the using the second derivative of the spectra. In order to validate the calibration model, three separate biodiesel samples were used and analysed. In this work it is successfully demonstrated that NIR spectroscopy-based non-destructive technique gives fast measurements within less than 60 s of time and more accurate measurements with very low error of 1.1%. Statistical t -test showed that all the t-values of the validation samples were less than tc (t critical), giving t-value of 1.466 for linseed, 1.2556 for Algae and 0.4816 RME (Rapeseed Methyl Ester) compared with tc value of 2.365. This established that the proposed NIR method correlate well with the standard methods. The accuracy of the results for these samples for the different oxidative stability properties obtained from NIRS techniques was validated against the known value of all the oxidative properties and the percentage error was calculated and presented.