Near-Infrared Spectroscopy as a Tool for Simultaneous Determination of Diesel Fuel Improvers.

Diesel and biodiesel blends requires additives to improve fuel quality properties and engine performance. Diesel improvers are added before, during and/or after the fuel is blended. However, no accurate rapid and non-destructive analytical method is used during the fuel production that could determine the exact concentration of various types of improvers in diesel fuel. Thus, the aim of this study was to determine the concentration of several improvers in diesel matrices at the same time. Three types of diesel improvers, i.e., a cold-flow improver (CFI), a conductivity-lubricity improver (CLI), and a cetane number improver (CNI), were simultaneously determined by near-infrared (NIR) spectroscopy combined with multivariate statistical analysis and the partial least squares algorithm. The prediction models yielded high correlation coefficients (R 2) >0.99 and satisfactory values of the root mean square error of calibration as follows: CLI 4.2 (mg·kg-1), CFI 4.6 (mg·kg-1), and CNI 5.3 (mg·kg-1). The residual standard deviation of the repeatability was calculated to be around 8%. These results highlight the potential of NIR spectroscopy for use as a fast, low-cost, and efficient tool to determine the concentrations of diesel improvers. Moreover, this technique is suitable for application during refinery production, especially for the purpose of online monitoring to prevent overdoses of additives and save financial expenses.

Comparative Study of Light Cycle Oil and Naphthalene as an Adequate Additive to Improve the Stability of Marine Fuels.

Post the enforcement of the Global Sulphur Cap 2020, large amounts of marine fuel have been produced as a mixture of two or more components to achieve a sulfur level of less than 0.5 wt %. This has led to the wider use of diluents or cutter stocks from different origins to comply with the quality requirements of the ISO 8217 standard. These can often be bio- or alternative components with a lower level of stability. This makes it crucial to select components that are compatible and form a homogeneous mixture. The ISO 8217 standard provides commercial and operational protection; however, the stability of the fuel deteriorates over time. Therefore, the purpose of this study was to develop an adequate component or additive to improve the colloidal stability of marine fuels. A set of laboratory-prepared samples was used to verify the positive effects of the addition of a light cycle oil and also a newly developed additive (containing 30 wt % naphthalene as the simple diaromatic hydrocarbon in tetralin). The prepared fuels (with effective additive dosage), when stored for 60 days, maintained the total sediment accelerated (TSA) parameters, confirming the stability of the fuels. The additive converted the unsaleable fuel into fuel that complied with the requirements of ISO 8217. The developed additive can be used for industrial applications in marine fuel production.

Advanced Biofuels Based on Fischer-Tropsch Synthesis for Applications in Diesel Engines.

This paper focuses on the evaluation of the fuel properties of Fischer-Tropsch diesel blends with conventional diesel. Incorporating this advanced fuel into conventional diesel production will enable the use of waste materials and non-food materials as resources, while contributing to a reduction in dependence on crude oil. To evaluate the suitability of using Fischer-Tropsch diesel, cetane number, cetane index, CFPP, density, flash point, heat of combustion, lubricity, viscosity, distillation curve, and fuel composition ratios using multidimensional GC × GC-TOFMS for different blends were measured. It was found that the fuel properties of the blended fuel are comparable to conventional diesel and even outperform conventional fuel in some parameters. All measurements were performed according to current standards, thus ensuring the repeatability of measurements for other research groups or the private sector.

Advanced Biofuels Based on Fischer-Tropsch Synthesis for Applications in Gasoline Engines.

The aim of the article is to determine the properties of fuel mixtures of Fischer-Tropsch naphtha fraction with traditional gasoline (petrol) to be able to integrate the production of advanced alternative fuel based on Fischer-Tropsch synthesis into existing fuel markets. The density, octane number, vapor pressure, cloud point, water content, sulphur content, refractive index, ASTM color, heat of combustion, and fuel composition were measured using the gas chromatography method PIONA. It was found that fuel properties of Fischer-Tropsch naphtha fraction is not much comparable to conventional gasoline (petrol) due to the high n-alkane content. This research work recommends the creation of a low-percentage mixture of 3 vol.% of FT naphtha fraction with traditional gasoline to minimize negative effects-similar to the current legislative limit of 5 vol.% of bioethanol in E5 gasoline. FT naphtha fraction as a biocomponent does not contain sulphur or polyaromatic hydrocarbons nor benzene. Waste materials can be processed by FT synthesis. Fischer-Tropsch synthesis can be considered a universal fuel-the naphtha fraction cut can be declared as a biocomponent for gasoline fuel without any further necessary catalytic upgrading.

Attenuation of X and Gamma Rays in Personal Radiation Shielding Protective Clothing.

A collection of personal radiation shielding protective clothing, suitable for use in case of accidents in nuclear facilities or radiological emergency situations involving radioactive agents, was gathered and tested at the Nuclear Protection Department of the National Institute for Nuclear, Chemical and Biological Protection, Czech Republic. Attenuating qualities of shielding layers in individual protective clothing were tested via spectra measurement of x and gamma rays, penetrating them. The rays originated from different radionuclide point sources, the gamma ray energies of which cover a broad energy range. The spectra were measured by handheld spectrometers, both scintillation and High Purity Germanium. Different narrow beam geometries were adjusted using a special testing bench and a set of various collimators. The main experimentally determined quantity for individual samples of personal radiation shielding protective clothing was x and gamma rays attenuation for significant energies of the spectra. The attenuation was assessed comparing net peak areas (after background subtraction) in spectra, where a tested sample was placed between the source and the detector, and corresponding net peak areas in spectra, measured without the sample. Mass attenuation coefficients, which describe attenuating qualities of shielding layers materials in individual samples, together with corresponding lead equivalents, were determined as well. Experimentally assessed mass attenuation coefficients of the samples were compared to the referred ones for individual heavy metals.