Fuel Oil Testing

Pedrozo-Peñafiel, Marlin J., et al. Fuel 243 (2019): 493-500.

The quantification of aluminum (Al) and silicon (Si) in fuel oil is crucial for preventing equipment fouling, catalyst deactivation, and operational inefficiencies in refining and combustion processes. A refined X-ray fluorescence (XRF) spectrometry method was developed to accurately determine Al and Si in fuel oils and crude oils.

For fuel oil analysis, energy dispersive XRF (EDXRF) was applied, utilizing thin-film deposition on filter paper to minimize matrix effects. Calibration with organic standards provided reliable quantification, achieving limits of detection (LOD) of 1.6 µg g^-1 (Al) and 1.2 µg g^-1 (Si). However, crude oil analysis required sample ashing and fusion with Li₂B₄O₇, followed by aqueous phase quantification using matrix-matched calibration, improving sensitivity to 1.3 µg g^-1 (Al) and 0.7 µg g⁻¹ (Si).

To simplify crude oil analysis, wavelength dispersive XRF (WDXRF) was explored, allowing direct sample analysis after tetrahydrofuran (THF) dilution. This approach yielded enhanced selectivity and sensitivity, with LODs of 0.5 µg g^-1 (Al) and 0.3 µg g^-1 (Si), utilizing matrix-matched standards based on white clay dispersed in mineral oil.

The XRF-based methodologies offer a rapid, reliable, and cost-effective solution for monitoring Al and Si in fuel oils, supporting quality control in refining and combustion industries while reducing the need for extensive sample preparation.

Nechaeva, Daria, et al. Talanta 183 (2018): 290-296.

The quantification of hydrogen sulfide (H₂S) in fuel oil is essential due to its corrosive properties and environmental impact. A novel miniaturized, cost-effective, and selective procedure has been developed for H₂S determination, combining headspace liquid-phase microextraction (HS-LPME) with cyclic voltammetry detection on a paper-based analytical device (PAD).

The PAD, fabricated using a modified wax-dipping method, consists of hydrophobic and hydrophilic zones connected by microfluidic channels. It incorporates nickel (working), platinum (auxiliary), and Ag/AgCl (reference) electrodes, ensuring precise electrochemical detection. The HS-LPME process separates H₂S from fuel oil into an alkaline solution, converting it into sulfide ions for electrochemical analysis at +0.45 V.

Under optimized conditions, the method demonstrates excellent linearity for H₂S concentrations between 2 and 20 mg kg^-1, with a limit of detection (LOD) of 0.6 mg kg^-1 (3σ). This sensitive and selective approach was successfully applied to real fuel oil samples, providing accurate and reproducible results.

The integration of HS-LPME with PAD-based cyclic voltammetry offers a rapid, low-cost, and environmentally friendly alternative for H₂S monitoring in fuel oils, supporting quality control and regulatory compliance in the petroleum industry.

Li, J., Wang, W., & Li, F. (2024). Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 46(1), 15553-15566.

Blended fuel oils, particularly biodiesel-diesel mixtures, are gaining popularity as sustainable alternatives to conventional fossil fuels. However, precise determination of the biodiesel content is crucial for quality control, regulatory compliance, and optimization of fuel performance. This study explores a rapid, cost-effective method using ultraviolet-visible (UV-Vis) spectroscopy to quantify the blending ratio of biodiesel in fuel mixtures.

UV-Vis analysis of diesel/jatropha biodiesel blends reveals distinct absorption peaks, with a maximum at 324 nm. As biodiesel concentration increases, the absorbance at this wavelength systematically decreases, attributed to changes in conjugated double-bond structures within the fuel. By applying the Lambert-Beer law and subtracting the absorbance of pure diesel, a standard curve correlating biodiesel concentration with absorbance was established. The proposed model demonstrated high accuracy, with an error margin within ±0.1 for diesel-biodiesel blends and ±0.9 for complex mixtures containing vegetable oil.

This method provides a reliable approach for rapidly assessing biodiesel content in blended fuel oils, ensuring adherence to industry standards and enhancing fuel market transparency. The findings contribute to advancing biofuel technology, supporting its wider adoption while maintaining stringent quality assurance protocols.