Search Results (113)

Essential oils are natural products frequently subject to economically motivated adulteration with cheaper substances like vegetable oils, mineral oils, or organic solvents. This study developed and validated a rapid high-temperature gas chromatography with flame ionization detection (HTGC-FID) method for the simultaneous determination of high-boiling adulterants: triacylglycerides (vegetable oils) and medicinal white oil (mineral oil) in essential oils. The method utilizes on-column injection onto a DB-5 capillary column (30 m × 0.53 mm, 0.88 μm) with a temperature program from 60 to 380 °C and hydrogen carrier gas. Validation parameters demonstrated excellent linearity (R² = 0.9957–0.9978), high repeatability (content RSD < 3%), and sufficient sensitivity (LOQ of 0.03% for triacylglycerides, and 0.63% for medicinal white oil). The method was successfully applied to 20 commercial essential oils. While medicinal white oil was undetected, several samples contained triacylglycerides (up to 3.79%) and other adulterants (up to 52%). Significantly reduced response factors confirmed extensive adulteration in some products. The proposed HTGC-FID method represents a simple, cost-effective, and efficient tool for routine quality control, enabling direct quantification of high-boiling adulterants without tedious sample preparation. Full article

The sustainable development of all economic sectors, including transport, requires decarbonization approaches that reduce greenhouse-gas emissions while preserving operational viability. This article develops a segment-based preliminary multi-criteria framework for evaluating the rational applicability of decarbonization technologies to commercial fishing vessels and demonstrates it for existing medium-to-large trawlers. The central premise is that decarbonization technologies cannot be ranked universally for the whole fishing fleet because vessel type, fishing gear, operating cycle, autonomy, onboard energy demand, and port dependence strongly affect practical applicability. Ten alternatives are assessed: sustainable drop-in biofuels/biodiesel/HVO (Hydrotreated Vegetable Oil), LNG/BioLNG/LBG, methanol, hydrogen fuel cells, ammonia, hybrid systems, operational measures, hull-form or hydrodynamic modifications, waste heat recovery and wind-assisted propulsion. Seven benefit-type criteria are combined using trawler-specific Rank-Order Centroid weights, Simple Additive Weighting, and a dynamic rationality extension for 2026, 2030, 2040, and 2050. The 2026 baseline results place operational measures and sustainable drop-in biofuel/HVO pathways in the leading practical group, while hydrogen and ammonia remain weak because of storage, safety, infrastructure, cost, and integration constraints. By 2050, a mixed long-term group emerges where HVO, LNG/BioLNG/LBG, methanol, ammonia, and hydrogen are all relevant, with no single dominant alternative. The framework supports early-stage screening before vessel-specific LCA, LCCA, CFD, safety assessment, and retrofit or newbuild design. Although this methodological approach was demonstrated for existing medium-to-large trawlers, the authors believe that it can be adapted for retrofit cases, other fishing vessel segments, and other types of seagoing vessels. Full article

Waste vegetable oil-based regenerants (WVO-Rs) are essential for sustainable asphalt pavements; however, their formulation optimization frameworks remain insufficient, and both the component synergy and the multi-component regeneration mechanism remain unclear. In this study, Response Surface Methodology was employed to optimize the WVO-R formulation by jointly considering the multi-temperature performance and interfacial water stability of the regenerated bitumen. Multi-scale performance tests and quantum chemical calculations were conducted to comprehensively evaluate its regeneration effectiveness and thermal behavior and to elucidate the underlying molecular mechanisms. The results indicate that the formulation optimization framework dominated by multi-temperature rheological properties and interfacial water stability exhibits superior engineering applicability compared with traditional methods, and the optimal WVO-R formulation corresponds to a mass ratio of WVO:DBP:CPR:SCA:ATO = 100:23.6:14.4:1.7:1. The WVO-R achieves optimal comprehensive regeneration at a dosage of 6–8%, exhibiting excellent thermal and storage stability along with uniform mixing. At the molecular level, the WVO-R forms a dynamic and stable molecular aggregate structure by integrating inherently stable components, leveraging the bipolar silane coupling agent to regulate critical polarity mismatches of dibutyl phthalate (DBP), and establishing a synergistic interaction network dominated by dispersion forces, supplemented by localized stacking and hydrogen-bonding interactions. On this basis, Oleic acid further depolymerizes aged asphaltene (AAS) aggregates through hydrogen bonding interactions, DBP enhances the reversible deformation capacity of AAS via π–π stacking effects, and the overall WVO-R components reshape the electronic structural characteristics of AAS to levels comparable to virgin asphaltene by smoothing the surface electrostatic potential gradient and suppressing electronic reactivity. Overall, this study establishes a systematic framework for WVO-Rs that integrates formulation optimization, regeneration performance evaluation, thermal behavior analysis, and molecular-level mechanism elucidation, thereby providing solid theoretical support for the efficient design and engineering application of bio-based bitumen regenerants. Full article

This paper studies the dynamics of a low-density gas directly injected onto a flat wall, focusing on the influence of different pressure ratios (PRs) and plate position. Due to safety reasons, Helium (He) was employed as substitute to reproduce the mixing characteristics of hydrogen. A Nd:YAG laser has been used to generate the luminous background in the constant volume chamber (CVC) and vegetable oil particles as trackers to identify the induced flow-field. Two configurations were investigated: the first, with a flat wall perpendicularly positioned at an axial distance of 10 mm from the injector tip, and the second with the same plate at 30 mm downstream of the injector, inclined at 30°. The pressure of injection was swept from 20 to 50 bar, while the backpressure inside the CVC ranged from 2 to 6 bar to enable the reproduction of five different values of PRs: 3, 4, 7, 10 and 17. The comparison of the results in the two configurations has highlighted the role of the plate at short distance in decelerating the jet speed (230 m/s to 160 m/s) while improving the vorticity intensity (+10%). In addition, a stagnation region was observed to form on the flat wall, downstream of the injector axis for 10 mm configuration. In this area the velocity ranged from 50% to 60% compared to the average jet speed. This phenomenon was noted to be less pronounced with the 30 mm, 30° configuration that led to a more contained speed reduction to 150–160%. Full article

The development of modern society has intensified fossil fuel consumption, resulting in the depletion of oil resources and rising greenhouse gas emissions. In this context, the promotion of renewable alternatives in the transport sector has become essential, with Hydrotreated Vegetable Oil (HVO) emerging as a promising transitional fuel due to its compatibility with conventional diesel engines. To ensure proper engine operation and performance, the physical properties and chemical structure of HVO must be accurately characterized. Gas chromatography is commonly used for this purpose. While dedicated gas chromatography methods for HVO are available on specialized equipment, this study proposes a chromatographic method applicable to conventional gas chromatograph systems equipped with a flame ionization detector, enabling the analysis of HVO using commonly available laboratory equipment. The method was developed using commercially available HVO and pure n-alkanes (C₅–C₁₈) as reference compounds for component identification. The proposed approach enabled the estimation of carbon and hydrogen atom numbers in the analyzed fuel fractions and the determination of the stoichiometric air. The calculated values show good agreement with the literature data, confirming the reliability and applicability of the proposed boiling-point-based chromatographic method. Full article

The effective utilization and effective valorization of various organic industrial wastes have become increasingly important issues. One significant area for enhancing the circular economy is the processing of waste generated from vegetable oils and animal fats. This article focuses on the processing and use of soapstocks, which result from the chemical reaction between fatty acids and alkali. These soapstocks represent the most significant portion (approximately 70–90 wt% by weight) of waste produced by the oil and fat industry. The raw material for this study was soapstock obtained from the neutralization of sunflower oil at the PJSC “Zaporizhzhya Oil and Fat Plant,” designed by the Belgian company “De Smet.” The soapstock yield was found to be 9.95 wt% based on 100 wt% oil. Through a series of treatments involving water, acid, and multiple washes, a low-sulfur fuel component was produced that nearly meets the standards for boiler fuels as outlined in DSTU 4058-2001 and PN-C-96024:2020, except for the heat of combustion. It fully complies with the requirements specified in ISO 8217:2024. The sulfur content of the final product was determined to be 0.12 wt%. Additionally, the fuels produced contained 75.33 wt% carbon, 11.64 wt% hydrogen, and 12.00 wt% oxygen. Due to the relatively low oxygen content, the resulting product exhibits approximately twice the heat of combustion of similar fuels derived from other waste streams in the oil and fat industry. Full article

In this study, a techno-economic and carbon footprint (GHG, CO₂-equivalent) analysis was conducted on two alternative biofuels, green diesel and bio-jet fuel, produced from renewable lipids. The focus of the work is the comparison of various lipid feedstocks, including waste cooking oil, and four types of vegetable oils: cardoon, soybean, palm, and sunflower. Process optimization and design were performed to minimize production costs by using the process simulation software Aspen Plus^®. Green diesel and bio-jet fuel were obtained via hydrodeoxygenation and hydroisomerization/hydrocracking, respectively. Sensitivity analyses confirmed consistent results across the tested vegetable oils. Hydrodeoxygenation achieved triglyceride molar conversions exceeding 97%, with overall mass yields into the diesel fraction surpassing 79%. Conversely, hydroisomerization/hydrocracking of green diesel resulted in over 90% conversion of n-paraffins and more than 50% overall mass yield. The economic analysis showed that the primary cost factor influencing the payback selling price of the biofuels is the price of the lipid feedstocks. Biofuels are economically viable only when lipid prices are below 1000 €/ton and hydrogen prices are below 3000 €/ton. An important aspect is also represented by the combined-cycle energy recovery system, which strongly affects the overall capital cost and increases internal power generation efficiency. The carbon footprint calculated over a cradle-to-grave boundary showed shows net GHG reductions versus the fossil reference fuels for all scenarios. Net avoided emissions range from 1.74 to 3.63 kgCO₂-eq/kg green diesel and from 0.80 to 3.70 kgCO₂-eq/kg bio-jet fuel across the investigated feedstocks, approximately 40–84% and 20–95% of the respective savings relative to the fossil reference fuels under the stated background and logistics assumptions. Results are expressed per kg of produced fuel as a functional unit, using literature-derived upstream emission factors for oil supply and background inputs (hydrogen, Italian grid electricity and transport). For the bio-jet configuration, co-product burdens were partitioned by mass; the Discussion section highlights the sensitivity of the GD vs. BJF comparison to co-product handling and allocation choices. In this context, the choice of feedstock is essential in establishing the resulting GHG intensity of the two biofuels. From both economic and climate change perspectives, waste cooking oil emerges as the most promising option, particularly given its classification as waste-derived feedstock in the system boundary, unlike the virgin oil sources. Full article

In this study, bio-based polyurethanes (PUs) were synthesized using renewable polyols derived from sunflower seed oil, aiming to develop flexible yet robust polymeric films and scaffolds. Given their composition and favorable physico-chemical properties, these materials may represent promising candidates for the design and development of advanced biomedical systems. Two distinct oil polyols were prepared via glycerol transesterification (GM) and epoxidation (EPO) with hydrogen peroxide/glacial acetic acid, respectively. These polyols, in combination with poly(tetramethylene ether) glycol (PTMEG) and/or poly(ethylene glycol) (PEG), served as diol components in a one-step reaction with 1,6-hexamethylene diisocyanate (HDI). The structure of the polyol precursors was thoroughly characterized by MALDI-TOF MS and NMR spectroscopy, confirming successful functionalization. The resulting PU films exhibited excellent flexibility (885%) and mechanical properties (23 MPa), as evaluated by ATR-FTIR, Tensile test, DSC, DMA and SEM methods. The crosslink density of the order of 10⁻³ also contributes to the development of outstanding mechanical properties. Stress relaxation experiments were described using a stretched exponential (Kohlrausch–Williams–Watts) model to capture the viscoelastic behavior of the materials. In addition, stress vs. relative elongation curves revealing strain-hardening behavior were also analyzed and modeled mathematically to better describe the mechanical response under deformation. Furthermore, salt leaching techniques were employed to fabricate porous scaffolds. This work highlights the versatility of vegetable oil-based feedstocks in producing functional polyurethanes with tunable mechanical properties for applied polymer systems. Full article

This article discusses the potential of using the double-Wiebe function to model combustion in a compression-ignition engine fueled by diesel fuel or its substitutes, such as hydrotreated vegetable oil (HVO) and rapeseed methyl ester (RME), and hydrogen injected into the engine intake manifold. The hydrogen amount ranged from 0 to 35% of the total energy content of the fuels burned. It was found that co-combustion of liquid fuel with hydrogen is characterized by two distinct combustion phases: premixed and diffusion combustion. The premixed phase, occurring just after ignition, is characterized by a rapid combustion rate, which increases with an increase in hydrogen injected. The novelty in this work is the modified formula for a double-Wiebe function and the proposed parameters of this function depending on the amount of hydrogen added for co-combustion with liquid fuel. To model this combustion process, the modified double-Wiebe function was proposed, which can model two phases with different combustion rates. For this purpose, a normalized HRR was calculated, and based on this curve, coefficients for the double-Wiebe function were proposed. Satisfactory consistency with the experiment was achieved at a level determined by the coefficient of determination (R-squared) of above 0.98. It was concluded that the presented double-Wiebe function can be used to model combustion in 0-D and 1-D models for fuels: RME and HVO with hydrogen addition. Full article

Sustainable development and growing energy demand require the search for alternative fuels, especially for heavy transport. The study compared diesel fuel (DF), hydrogenated vegetable oil (HVO) and fuels from the pyrolysis of polypropylene (PPO), polystyrene (PSO) and car tyres (TPO). The lowest cold filter plugging point values were obtained for HVO (−38 °C) and PSO (−29 °C). TPO and DF were in the moderate range, while PPO achieved the worst result (−10 °C). Only DF met the EN 590 standard requirements for density at 15 °C (0.820–0.845) g/cm³. HVO and PPO were approx. 5% below the lower limit, while PSO and TPO exceeded the upper limit. All samples except PPO, which was below the lower limit, met the kinematic viscosity requirement according to the same standard at 40 °C (2.0–4.5) mm²/s. Based on a series of tribological tests, it was found that DF (400 µm) had the lowest lubricity expressed by the WSD index, while PSO (246 µm) had the highest. All samples tested met the requirements of EN 590, ASTM D975 and the Worldwide Fuel Charter in this respect. The results provide valuable information for engine technology, enabling more accurate durability predictions and fuel mixture optimization. Full article

Crude hemp (Cannabis sativa L.) seed oil (HSO) has a high degree of unsaturation, which has increased its interest in many industrial applications, especially epoxy-resin production. Crude HSO is refined to remove impurities and pigments; however, refining after epoxidation (post-epoxidation refining) also removes impurities and side products, similar to the vegetable oil refining process. Therefore, this study evaluates if it is worth refining crude HSO before epoxidation (pre-epoxidation), and to what extent pre-refining (before epoxidation) is needed to maintain yield and quality. Crude, degummed, and bleached HSOs were epoxidized at 60 °C for 5.5 h using amberlite 120H+ solid catalyst. The cumulative recovery yield, oxirane, conversion, color, and other quality parameters were analyzed before and after epoxidation of HSOs. Results showed that the recovery yield pre- and post-epoxidation of the epoxidized hempseed oils (EHSOs) ranged from 74 to 85%, with the bleached EHSO having the lowest yield. The oxirane content and epoxy conversion ranged from 8.4 to 8.6% and 99.5%, respectively. There was a significant decrease (approximately 99%) in the chlorophyll color content after epoxidation for samples that were not bleached initially with bleaching earth. Hydrogen peroxide was very effective in bleaching the HSO. Other quality parameters did not show any significant benefit from pre-epoxidation bleaching of the HSO. Therefore, it is recommended to directly epoxidize crude HSO or degummed HSO. Full article

The aim of this study was to explore the use of neural networks as a decision-support tool for sustainable oilseed processing. The investigation focused on how different production profiles (crude vegetable oil, refined oil, hydrogenated oil and margarine) affect electricity and water use in selected Polish processing plants. The collected data were first grouped with cluster analysis to identify similar operational cases. The clusters were then visualized with a Self-Organizing Map (SOM), producing a two-dimensional topological feature map. This analysis indicated a subset of data for which it was appropriate to build predictive models of electricity and water consumption. Multi-layer perceptron (MLP) neural networks yielded highly accurate predictions of electricity (R² = 0.967 on the test set) and water (R² = 0.967 on the test set) use in oilseed processing. The resulting models can assist in selecting the most energy- and water-efficient processing configuration. Full article

The main objective of this research consists in finding a rapid method for cheese lipidomics based on NMR data. This study plays an important role in differentiation and characterization of cheese samples in accordance with fat composition, especially in the case of fat substitution with exogenous animal or vegetal fat. Our findings play an important role in relation to religious requirements regarding non-allowed foods (pork fat, for example, in some cultures) and in the correct characterization of foods according to their lipidic profile. The approach consists in establishing a fingerprint region (0.86–0.93 ppm from ¹H-NMR spectra) and then creating a database of the results obtained. The evaluation of the long-chain saturated fatty acids and the saturated short-chain fatty acids (C4 to C8) was established with a newly developed set of equations that make the computation possible even when mixtures of fats from different sources are present. This was accomplished by developing a new method for quantification of the fatty acid composition of different types of cheese, based on ¹H-NMR spectroscopy. Principal component analysis (PCA) was applied to 40 cheese samples with varying degrees (0%, 5%, 12%, or 15%) of milk fat substitution (pork fat, vegetable fat, hydrogenated oils) and different clotting agents (calcium chloride or citric acid). The best sample discrimination was achieved using fatty acid profiles estimated from ¹H-NMR data (using a total of six variables), explaining 89.7% of the total variance. Clear separation was observed between samples containing only milk fat and those with added fats. These results demonstrate that the integration of ¹H-NMR spectroscopy with principal component analysis (PCA) provides a reliable approach for discriminating cheese samples according to their fat composition. Full article

In the era of depletion of fossil fuels, there is an intensive search for renewable fuels for the internal combustion engine, which is the most efficient thermal machine in the power range of several kW to several MW. Hence, this article discusses the results of research on the combustion of renewable fuels such as hydrotreated vegetable oil (HVO) and the rapeseed methyl ester (RME) with the addition of hydrogen, injected in its gaseous form into the intake manifold. The thermodynamic analysis presented in the article discusses progress in the combustion process of these fuels depending on the hydrogen content. The parameters for diesel fuel combustion are given as a reference point. Based on the obtained results, one can conclude that adding hydrogen increases the maximum combustion pressure in the cylinder and significantly accelerates the combustion process in the premixed combustion phase, thus reducing the share of the diffusion combustion phase. This significantly affects exhaust toxic emissions. In connection with this, a shortening of the flame kernels development phase was observed, calculated as the time expressed by the crank angle, to release heat of 10%, and a slight extension of the main combustion phase, managed as the period of the heat released from 10 to 90% was observed as well. Full article

Industrial trans and saturated fatty acids, which are key components of solid fats used in food products, should be replaced with unsaturated fatty acids from vegetable oils to reduce cardiovascular risk. However, unsaturated oils lack the structured networks required to replicate the technological properties of solid fats. Oleogelation, especially using polymer-based networks, offers a promising solution. This study optimized chitosan-based oleogels crosslinked with vanillin to mimic the texture of butter, partially hydrogenated fat, margarine, and palm fat while minimizing oil loss. Oleogels were prepared via the emulsion-template method and optimized through a central composite design combined with a desirability function, evaluating the effects of chitosan, vanillin, Tween^® 60 concentrations, oil type (canola or soybean), and storage temperature (4 °C or 25 °C). Optimized oleogels were characterized for their rheological and microstructural properties. Chitosan concentration primarily governed oil loss, hardness, and adhesiveness of oleogels, independent of the oil phase and storage temperature. However, storage at 4 °C reduced oil loss but increased the hardness and adhesiveness compared to storage at 25 °C. The highest desirability scores (0.72 to 0.94) were achieved in soybean oil oleogels with 0.99% chitosan, 0.24–0.32% vanillin, and 0.17–0.18% Tween^® 60, closely mimicking the texture of butter and margarine. These oleogels demonstrated stronger networks, enhanced gel strength, and elasticity, positioning them as viable alternatives to conventional solid fats. Full article