Search Results (28)

Background: Aromatic plants like peppermint (Mentha x piperita, Lamiaceae) have a long tradition of use. Most of the plant material is used to produce herbal drugs and for the isolation of essential oils. However, since essential oils are present in very small amounts, the largest proportion of plants remains unused. Objectives: The aims of this study were the analysis of chemical, biochemical, antimicrobial, and pharmacological properties of peppermint waste material extracts (derived from stems, post-distillation waste, and deodorized leaves) in comparison with the officially prepared extract. Results: The obtained results revealed that the investigated peppermint waste extracts (PWEs) are a rich source of phenolic compounds, where rosmarinic acid was determined as the dominant one (7.05–21.19 mg/g d.e.). Antioxidant potential and hepatoprotective effect of PWE were comparable with the official extract, where the most active ones were those prepared by treating the deodorized leaves with both 45% and 75% ethanol. In addition, PWE exhibited notable antimicrobial and anticholinesterase activity. Results of pharmacological studies on experimental animals showed that peppermint extracts (official and those made from deodorized leaves) did not interfere with the effect of the tested drugs, midazolam and fluoxetine. The examined extracts neither exerted an influence on motor coordination nor acted as antidepressants. Results of the elevated plus maze test indicated that PWE affected the activity of the central nervous system. Conclusions: PWEs represent a significant source of phenolic compounds, especially rosmarinic acid, and they can be used in the pharmaceutical industry to produce various herbal products and in the food industry as natural additives. Full article

To apply molecular dynamics (MD) simulations in the study of virgin asphalt binder, researchers have relied on basis sets of representative model structures from the SARA categories of saturated aliphatics (S), naphthenic aromatics (A), polar aromatics or resins (R), and asphaltenes (A). The evolution of these model compounds for MD of binder is reviewed with emphasis on addition of oxidized species for simulations of recycled aged binders. The level and type of oxygen functional groups in many MD simulations are not consistent with reported findings. Oxidation of primary, secondary, and tertiary benzylic carbons has been used as a rational approach to generate an extended basis set with functional groups reflecting ageing of virgin binder model compounds. Moieties known to be present in aged binder, though not wholly represented in prior work, include carboxylic acids, ketones, alcohols, anhydrides, and sulfoxides. A specific modified basis set for oxidized asphalt binder is proposed along with a methodology for generating other oxygen-consistent basis sets from virgin binder structures. An example illustrates how selection of compounds from the modified basis set and their amounts can be used to match observed functional group compositions. The objective of this approach is more realistic representation of the molecular interactions between aged asphalt binder structures and those in a waste cooking/motor oil, for example, used to rejuvenate the rheological properties of a binder. Full article

Contemporary climate challenges and energy security issues once again demonstrate that the transition to alternative motor fuels is a key and priority task for ensuring sustainable development in European Union countries, as well as in Ukraine. This review provides a comparative analysis of the physical, chemical, and performance properties of biodiesel fuels derived from 17 lipid-based feedstocks, including vegetable oils, animal fats, food industry waste, and microalgae. This study investigates the influence of fatty acid composition and transesterification alcohol type on key fuel properties, including density, viscosity, cetane number, pour point, heat value, and flash point. The results show that biodiesel fuels with a high content of saturated fatty acids exhibit higher cetane numbers and energy content, while biodiesel fuels with a high content of unsaturated fatty acids possess improved viscosity and cold flow properties. Camelina, rapeseed, and used cooking oil are identified as being particularly promising feedstocks based on their performance and availability in the European and Ukrainian dimensions. These findings are supported by a SWOT analysis and cost–benefit comparison, providing practical insights into the feasibility and scalability of biodiesel production pathways. Full article

The possibility of using the secondary cellulose-containing raw material resource of the cereal production of buckwheat, namely, its husk, as sorbents for the collection of oil and oil products is shown. In order to increase the yield of the finished product, develop porosity, and improve the sorption characteristics of the buckwheat husk, methods for its physical and chemical modification are proposed. The effect of the modification modes on the parameters of the porous structure, as well as the sorption capacity of the developed materials for various types of oil products, was studied. The selection of the optimal parameters of the buckwheat husk modification was carried out, ensuring the production of effective unsinkable sorbents based on the buckwheat husk with a reserve buoyancy of more than 20 days and a high sorption capacity of sorbents for oil of up to 6.1 g/g and waste motor oil of up to 4.9 g/g. The use of the buckwheat husk as a sorbent allows not only the elimination of oil pollution on both water and surfaces but also solving the problem of the disposal of agricultural waste. Full article

Stockpiled end-of-life tires (ELTs) pose a serious environmental concern. In the current investigation, ELT pyrolysis oil (i.e., pyro-oil) was studied as a potential additive to conventional motor oil. The pyro-oil samples were mixed in different concentrations of 10 to 50 wt.% with commercial virgin motor oil to obtain a lubricant mixture. Chemical analyses were performed for the tire-recycled derivative material, as a potential route to utilize pyro-oils, valorize ELT waste, and reduce production costs of motor oil lubricants. Rheological examinations were performed to explore the impact of the pyro-oil on the rheological properties of the motor oil under several shearing rates and temperatures. Tribological analyses of the lubricant mixtures and the pure motor oil were accomplished to study the influence of the pyro-oil additive on the tribological behavior of motor oils. Lastly, thermal stability and wettability examinations were executed to assess the thermal and wetting properties of lubricant mixtures. The obtained results showed that adding a low concentration of the pyro-oil (≤10%) will sustain the motor oil’s chemical, wettability, thermal stability, rheological, and tribological properties, signifying a viable application of recycled ELTs and helping to reduce their environmental and economic impact. These findings offer a feasible route of use in the future to obtain low-cost oils with market specifications, utilizing pyro-oil as a sustainable and environmental oil additive. Full article

This study evaluated the potential of Y. lipolytica (CBS 2075 and DSM 8218) to grow in waste motor oil (WMO) and produce valuable compounds, laying the foundation for a sustainable approach to WMO management. Firstly, yeast strains were screened for their growth on WMO (2–10 g·L⁻¹) in microplate cultures. Despite limited growth, the CBS 2075 strain exhibited comparable growth to control conditions (without WMO), while DSM 8218 growth increased 2- and 3-fold at 5 g·L⁻¹ and 10 g·L⁻¹ WMO, respectively. The batch cultures in the bioreactor confirmed the best performance of DSM 8218. A two-stage fed-batch strategy–growth phase in aliphatic hydrocarbons, followed by the addition of WMO (one pulse of 5 g·L⁻¹ or five pulses of 1 g·L⁻¹ WMO), significantly increased biomass production and WMO assimilation by both strains. In experiments with five pulses, CBS 2075 and DSM 8218 strains reached high proteolytic activities (593–628 U·L⁻¹) and accumulated high quantities of intracellular lipids (1.3–1.7 g·L⁻¹). Yeast lipids, mainly composed of oleic and linoleic acids with an unsaturated/saturated fraction > 59%, meet the EU biodiesel standard EN 14214, making them suitable for biodiesel production. Full article

Oil spills occur during different operations in the energy sector, such as crude oil transport, tank filling and cleaning, and fueling. Such spills are one of the major causes of the accumulation of oil derivatives in the environment, requiring the remediation of soil and marine environments. The production of a biosurfactant by Starmerella bombicola ATCC 222214 was maximized by investigating the effect of different carbon/nitrogen sources and culture conditions. The mineral medium selected for its production was supplemented with 2.0% potato peel flour, 5.0% waste canola frying oil, and 0.20% urea. The culture conditions were a 200 rpm shaking speed, a fermentation time of 180 h, and a 4.0% inoculum size. The yield of isolated biosurfactant was 7.72 g/L. The emulsification rates of heavy oil and motor oil were 65.55 and 95.00%, respectively, indicating an affinity for complex hydrocarbons. In stability tests performed at different pH values, temperatures, and NaCl concentrations, the surface tension ranged from 27.14 to 31.08 mN/m. The critical micelle concentration was 2.0 g/L, at which the surface tension was 33.26 mN/m. The biosurfactant was composed of 6,6-dimethoxy-octanoic acid and azelaic acid, and it exhibited low toxicity to Brassica oleracea and Solanum lycopersicum. In the kinetic test, the biosurfactant allowed for the removal of 82.30%, 96.65%, and 98.25% of exhaust motor oil from sand, silty soil, and clay soil, while in the static test in packed columns, the removal yields were 66.62%, 63.03%, and 58.45%, respectively. The biosurfactant produced in this study is promising for environmental remediation applications in the energy sector. Full article

Herein, raw and alkali-treated hydrochars from biomass waste are prepared as a highly active catalyst for the conversion of waste motor oil into diesel-like fuels. Among all materials, hydrochar obtained at 250 °C and subsequent alkali activation with KOH showed a 600% improvement of the kinetic constant from 0.0088 to 0.0614 m⁻¹. Conversion values at the same conditions were also improved from 66 to 80% regarding thermal and catalytic cracking, respectively. Moreover, the activation energy was also reduced from 293 to 246 kJ mol⁻¹ for thermal and catalytic cracking, respectively. After characterization, the enhanced catalytic activity was correlated to an increased surface area and functionalization due to the alkali activation. Finally, the liquid product characterization demonstrated that catalytic cracking is more effective than thermal cracking for producing hydrocarbons in the diesel range. In particular, hydrochar-based catalysts are suggested to promote the formation of specific hydrocarbons so that the carbon distribution can be tailored by modifying the hydrothermal treatment temperature. Full article

The impact of dumping plastic waste is realized in different ecosystems of the planet. Several methods have been adopted to dispose of these wastes for energy recovery. This study, for the first time, proposed the Box–Behnken design technique to optimize the pyrolysis process parameters for fuel oil production from waste polypropylene (PP) grocery bags using a semibatch-type pyrolytic reactor. The semibatch-type pyrolytic reactor was developed and employed to produce fuel oil from waste PP grocery bags. The effect of different process parameters on fuel oil production was comprehensively analyzed using the response surface methodology (RSM) with the conjunction of the Box–Behnken design (BBD). The BBD facilitates the prediction of the response variables with respect to changes in the input variables by developing a response model. The BBD was used to optimize the process parameters, such as the reaction temperature (400–550 °C), nitrogen flow rate (5–20 mL min⁻¹), and substrate feed rate (0.25–1.5 kg h⁻¹), and their effect on the responses were observed. The optimum response yields of the fuel oil (89.34 %), solid residue (2.74%), and gas yield (7.92%) were obtained with an optimized temperature (481 °C), a nitrogen flow rate (13 mL min⁻¹), and a feed rate (0.61 kg h⁻¹). The quadratic model obtained for the fuel oil response denotes the greater R² value (0.99). The specific gravity and calorific value of the fuel oil were found to be 0.787 and 45.42 MJ kg⁻¹, respectively. The fuel oil had higher research octane number (RON) (100.0 min) and motor octane number (MON) (85.1 min) values. These characteristics of the fuel oil were matched with conventional petroleum fuels. Further, Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectroscopy (GC-MS) were used to analyze the fuel oil, and the results revealed that the fuel oil was enriched with different hydrocarbons, namely, alkane (paraffins) and alkene (olefins), in the carbon range of C₄–C₂₀. These results, and also the fractional distillation of the fuel oil, show the presence of petroleum-range hydrocarbons in the waste PP fuel oil. Full article

At present, the hydraulic systems of electric forklifts and traditional internal combustion forklifts are mostly valve-controlled speed-regulation systems, which have large throttling losses and potential energy waste. To further improve the energy-saving ability of electric forklifts, the forklift’s common working conditions are analyzed in this paper. A throttling loss energy-regeneration system based on pressure difference pump control is designed, and the system’s working principle is described. Aiming to deal with the problem that the pump−valve compound speed regulation with constant pressure difference could not realize high controllability and energy saving at the same time, a control strategy for variable pressure difference pump−valve compound speed regulation based on pressure balance control is proposed. The handle signal is positively related to the target speed of the oil cylinder. In the low-speed stage, the closed-loop control of the actual output torque of the motor/generator keeps the pressure difference across the proportional throttle valve unchanged, and the speed adjustment is realized by changing the opening of the proportional throttle valve. In the high-speed stage, the valve opening area is kept unchanged and the target pressure difference is changed to achieve the target speed. Finally, the feasibility of the control strategy is verified through an AMESim simulation, and the minimum pressure difference switching point is determined through experiments. The experiments show that the system’s energy-saving efficiency can reach 21.5% under a 1 t load. With the increase in the load, the system’s energy-saving efficiency can be further improved. Full article

Rapid migration towards cities is occurring due to economic and social reasons. Industrialization, urbanization, and changes in consumption habits are creating environmental problems. Sustainable urban planning is necessary to ensure people’s quality of life in future cities. The establishment of strategic waste management processes is crucial. This topic encompasses the awareness, education, adaptation, and implementation of them by urban residents. The “Zero Waste Project” was initiated in Türkiye in 2017, and local governments have a significant responsibility for its implementation. City administrations strive to create clean, healthy, contemporary, and livable environmental conditions for their stakeholders. The aim of this study was to examine the Zero Waste Project system, an important approach for planning sustainable cities. Istanbul has 39 district municipalities. In this study, the amount of waste collected by the municipalities affiliated with Istanbul within the scope of the “Zero Waste Project” in 2022 was determined. Data were obtained from the “Zero Waste Project Implementation” sections of the 2022 activity reports of the 39 district municipalities. Data on the quantities in the categories of packaging, glass, clothing and textiles, electronics, batteries, vegetable oil, pharmaceuticals, tires, motor oil, and wood waste were obtained. This help us understand, the implementation of waste management systems in Istanbul district municipalities. In addition, the “Zero Waste Awareness and Incentive” activities carried out in Istanbul district municipalities are emphasized. The Zero Waste Project has the potential to improve the sustainability of urban living. It can be evaluated as a participatory environmental policy in terms of sustainable urban planning. Full article

Research was carried out on the possibility of involving oil refining wastes and petrochemical by-products in marine fuel oil. It was shown that the properties of the studied products (VAT distillation residue of butyl alcohols, heavy pyrolysis tar, desalted phenol production tar, waste motor oil mixture) mainly differ from primary and secondary oil refining products used in this fuel with increased toxicity (hazard classes 2 and 3). A clear disadvantage of waste motor oils is an increased content of metals, particularly zinc, calcium and phosphorus, which leads to high ash content. Recommended concentrations for introducing components into marine fuels are given. The influences of the composition and sulfur content on operational properties and quality indexes of VLSFO were also studied. It is shown that the use of products of deep hydrotreatment of vacuum-distillate fractions of oil processing can worsen its protective (anticorrosive) properties and colloidal stability; therefore, a reduction of sulfur content below 0.1% in this fuel is inexpedient without the use of additives. The requirements for VLSFO quality indicators have been developed. Application of VLSFO corresponding to the developed requirements will provide an increase in performance of ship power plants and the stability of VLSFO quality, which will contribute to cost reduction of ship owners when using it. Full article

Biodiesel is regarded as a low-carbon substitute for petroleum-based fuels. This research study aimed to investigate a 10 L batch-scale biodiesel production system from waste cooking oil (WCO) powered energy by solar energy and conventional electricity. The unit’s design considers the mass balance of the system’s constituent parts. The methoxide mixing chamber volume was calculated as 2.5 L with an electric agitator power requirement of 25 W. In comparison, the volume occupied by reactants in the stirred reactor was determined to be 14.5 L with a 250 W electric motor agitator. The WCO biodiesel was produced by a two-step process, i.e., esterification followed by a transesterification reaction using conventional electricity and solar power, yielding 92% and 90% by volume, respectively. The characteristics of WCO biodiesel produced from both energy systems was comparable to ASTM D6751. The total amount of conventional electricity and solar power required was 2.006 kWh and 1.0 kWh per 10 L, respectively. The WCO biodiesel’s mass performance was 64.02% and 62.10%, whereas the energy productivity was 0.0242 kg/MJ and 0.0235 kg/MJ from conventional electricity and solar energy systems, respectively. Therefore, solar energy systems can be employed in biodiesel production with a massive reduction in traditional energy requirements, thus reducing the production’s carbon footprint. Full article

Aggregation methods in group decision-making refer to techniques used to combine the individual preferences, opinions, or judgments of group members into a collective decision. Each aggregation method has its advantages and disadvantages, and the best method to use depends on the specific situation and the goals of the decision-making process. In certain cases, final rankings of alternatives in the decision-making process may depend on the way of combining different attitudes. The focus of this paper is the application and comparative analysis of the aggregation operators, specifically, arithmetic mean (AM), geometric mean (GM), and Dombi Bonferroni mean (DBM), to the process of criteria weights determination in a fuzzy environment. The criteria weights are determined using Fuzzy Multi-Criteria Decision-Making (F-MCDM) methods, such as Fuzzy Analytic Hierarchy Process (F-AHP), Fuzzy Pivot Pairwise Relative Criteria Importance Assessment (F-PIPRECIA), and Fuzzy Full Consistency Method (F-FUCOM), while the final alternative ranking is obtained by Fuzzy Weighted Aggregated Sum Product Assessment (F-WASPAS). A comparison of aggregation operators is done for the real case of location selection problem for a used motor oil transfer station in the regional center of Southern and Eastern Serbia, the city of Niš. The results obtained in this study showed that the views of different experts and application of a certain aggregation approach may have a significant impact on the values of criteria weight coefficients and further on the final ranking of alternatives. This paper is expected to stimulate future research into the impact of aggregation methods on final rankings in the decision-making process, especially in the field of waste management. Full article

Soils contaminated by waste motor oil (WMO) affect their fertility, so it is necessary to recover them by means of an efficient and safe bioremediation technique for agricultural production. The objectives were: (a) to biostimulate the soil impacted by WMO by applying crude fungal extract (CFE) and Cicer arietinum as a green manure (GM), and (b) phytoremediation using Sorghum vulgare with Rhizophagus irregularis and/or Rhizobium etli to reduce the WMO below the maximum value according to NOM-138 SEMARNAT/SS or the naturally detected one. Soil impacted by WMO was biostimulated with CFE and GM and then phytoremediated by S. vulgare with R. irregularis and R. etli. The initial and final concentrations of WMO were analyzed. The phenology of S. vulgare and colonization of S. vulgaris roots by R. irregularis were measured. The results were statistically analyzed by ANOVA/Tukey’s HSD test. The WMO in soil that was biostimulated with CFE and GM, after 60 days, was reduced from 34,500 to 2066 ppm, and the mineralization of hydrocarbons from 12 to 27 carbons was detected. Subsequently, phytoremediation with S. vulgare and R. irregularis reduced the WMO to 86.9 ppm after 120 days, which is a concentration that guarantees the restoration of soil fertility for safe agricultural production for human and animal consumption. Full article