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Abstract This research investigated the effect of ion concentration on the performance of low salinity water under different conditions. First, the effect of injection water composition on interparticle forces in quartz-kaolinite, kaolinite-kaolinite, and quartz-oil complexes was tested and modeled. The study used two oil samples, one with a high total acid number (TAN) and the other with a low TAN. The results illustrated that reducing the concentration of divalent ions to 10 mM resulted in the electric double layer (EDL) around the clay and quartz particles and the high TAN oil droplets, expanding and intensifying the repulsive forces. Next, the study investigated the effect of injection water composition and formation oil type on wettability and oil/water interfacial tension (IFT). The results were consistent with the modeling of interparticle forces. Reducing the divalent cation concentration to 10 mM led to IFT reduction and wettability alteration in high TAN oil, but low TAN oil reacted less to this change, with the contact angle and IFT remaining almost constant. Sandpack flooding experiments demonstrated that reducing the concentration of divalent cations incremented the recovery factor (RF) in the presence of high TAN oil. However, the RF increment was minimal for the low TAN oil sample. Finally, different low salinity water scenarios were injected into sandpacks containing migrating fines. By comparing the results of high TAN oil and low TAN oil samples, the study observed that fine migration was more effective than wettability alteration and IFT reduction mechanisms for increasing the RF of sandstone reservoirs.

This research investigated the effect of ion concentration on the performance of low salinity water under different conditions. First, the effect of injection water composition on interparticle forces in quartz-kaolinite, kaolinite-kaolinite, and quartz-oil complexes was tested and modeled. The study used two oil samples, one with a high total acid number (TAN) and the other with a low TAN. The results illustrated that reducing the concentration of divalent ions to 10 mM resulted in the electric double layer (EDL) around the clay and quartz particles and the high TAN oil droplets, expanding and intensifying the repulsive forces. Next, the study investigated the effect of injection water composition and formation oil type on wettability and oil/water interfacial tension (IFT). The results were consistent with the modeling of interparticle forces. Reducing the divalent cation concentration to 10 mM led to IFT reduction and wettability alteration in high TAN oil, but low TAN oil reacted less to this change, with the contact angle and IFT remaining almost constant. Sandpack flooding experiments demonstrated that reducing the concentration of divalent cations incremented the recovery factor (RF) in the presence of high TAN oil. However, the RF increment was minimal for the low TAN oil sample. Finally, different low salinity water scenarios were injected into sandpacks containing migrating fines. By comparing the results of high TAN oil and low TAN oil samples, the study observed that fine migration was more effective than wettability alteration and IFT reduction mechanisms for increasing the RF of sandstone reservoirs. [ABSTRACT FROM AUTHOR]

In this article, the laboratory device for processing milled cotton seeds in an electric magnetic field with an extremely high frequency and the results of the experiment obtained are described. The volume of macro pores of the gourmets (from 1875 to 7500), processed at 2450 MGs, 300 W, at 12-14% humidity for 13-15 minutes, increased by an average of 2.0 – 2.2 times after ultra-high-frequency processing, and when comparing the acid and perekis number indicators of high gossipol cotton oil with oil obtained using traditional technology, compared with processing using frequency Beams has been shown to be more efficient than in the traditional method [ABSTRACT FROM AUTHOR]

The study aims to analyse the qualitative characteristics of safflower oil, including its fatty acid profile, and determine the acid and peroxide numbers. The study also investigated the levels of heavy metals in the oil and assessed its potential as an inhibitor of α-amylase and α-glucosidase enzymatic activity. In this study, standardised methods were used to analyse the fatty acid composition of safflower oil using a standard mixture of 37 fatty acid methyl esters (Supelco™ 37 Component FAME Mix), which ensured high accuracy in determining the fatty acid composition. The physical properties of safflower oil, such as density (0.94) and specific gravity (0.917), depend on the fatty acid composition and temperature. The refractive index, determined at 1.469, was used to estimate changes in the oil’s unsaturation and viscosity (45.6 cP). Colour parameters (lightness 45.24, red-green scale -2.87, yellowblue scale 21.04) confirm the authenticity of the oil. The results of gas chromatographic analysis confirmed that the composition of the samples did not meet the requirements of the standard. The study also included the evaluation of the inhibitory activity of safflower oil against the enzymes α-amylase and α-glucosidase, where one of the samples showed significant inhibition of α-amylase activity and the other α-glucosidase activity, indicating their potential use as natural inhibitors. The safety control of heavy metal content showed that the levels of lead, cadmium and other toxic elements in the oil are well below the permissible limits, confirming its safety for consumption. These data indicate that, although some safflower oil samples do not meet the standards for fatty acid composition, its potential as a natural enzyme inhibitor and safety in terms of heavy metal content opens up prospects for further research and possible optimisation of production processes

The process of injecting carbon dioxide (CO2) into oil reservoirs involves intricate interactions between the reservoir's hydrocarbons and CO2, resulting in changes to various physiochemical properties such as interfacial tension (IFT) between complex acidic hydrocarbons and CO2. The IFT plays a crucial role in enhanced oil recovery by altering capillary force. Hydrocarbon mixtures usually contain a percentage of acidic organic compounds that pose a crucial effect on IFT measurement. In this study, benzoic acid was chosen as a representative of acidic compounds to study the effect of acid number (0.0–0.8 g/L) on the IFT between CO2 and different combinations of diesel fuel (representing aliphatic hydrocarbons) and gasoline (representing aromatic hydrocarbons). The volume ratios of the mixtures were varied at 0:100, 25:75, 50:50, 75:25 and 100:0%. Results revealed that increasing the acid number in gasoline from 0.2 to 0.8 g/L led to a significant change of more than 10 dyne/cm in the IFT between aromatic hydrocarbons and CO2. On the other hand, IFT alteration for aliphatic hydrocarbons was observed to be up to 5 dyne/cm. A new correlation for estimating IFT between CO2 and different hydrocarbons was also proposed with an average relative error of less than 9%. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the peroxide values, acid numbers, oxidative stability (Rancimat method), antioxidant activity (DPPH method), antimicrobial activity (disc diffusion method), sensory properties (9-point hedonic scale), and fatty acid profiles (FAME) of five edible oils purchased from local Slovakian producers—grape seed oil, flax seed oil, walnut oil, poppy seed oil, and milk thistle seed oil. The peroxide value ranged from 2.27 (milk thistle oil) to 8.51 (flax seed oil) mmol O2/kg. All these values were in accordance with regulations (upper limit of 20 mmol O2/kg). The values of the acid number ranged from 0.11 (walnut oil) to 2.49 (milk thistle oil) mg KOH/g, and were in accordance with regulations as they did not exceed the value of 4 mg KOH/g. The oxidation stability was the lowest in flax seed oil (0.18 h) and the highest in grape seed oil (2.05 h). In milk thistle oil, the highest amounts of oleic and behenic acids, in flax seed oil, the highest amount of α-linolenic acid, and in grape seed oil, the highest amount of linolic acid were determined. Antioxidant activity was the strongest in the sample of grape seed oil—65.53 mg TEAC/L (Trolox equivalent antioxidant capacity). Samples of flax seed oil showed the strongest inhibition of Candida albicans CCM 8186 (4.58 mm) and Bacillus subtilis CCM 2010 (0.31 mm). Poppy seed oil was determined to be the most inhibiting towards Klebsiella pneumoniae CCM 2318 (3.68 mm). Milk thistle oil showed the strongest inhibition of Clostridium perfringens CCM 4435 (6.31 mm). Grape seed oil was the most inhibitory towards Staphylococcus aureus subs. aureus CCM 2461 (5.32 mm). Walnut oil showed the strongest activity towards Yersinia enterocolitica CCM 5671 (6.33 mm). The sensory analysis resulted in the samples of walnut and grape seed oil being awarded the highest scores for smell, taste, and overall acceptability. The tested edible oils are rich in biologically active compounds with antioxidant and antimicrobial activities. Their consumption can have a positive effect on the functioning of the human body and its health. Proper storage conditions are, however, necessary because of the susceptibility of these oils to oxidation. [ABSTRACT FROM AUTHOR]

The robustness evaluation of the acid number analysis method in fish oil was carried out to see the effect of the type of ethanol used as a solvent in the titration process. The types of ethanol used in this study were pro analysis grade, pharma and food grade, and technical grade. The acid number values (mgKOH/g) in fish oil with various solvents obtained were 2.3955±0.3211 for pro analysis grade; 2.7932±0.2983 for pharma and food grade; 2.7812±0.3362 for technical grade 1; 2.7031±0.3405 for technical grade 2. The acid number for all types of ethanol has a value that is in accordance with the requirements of SNI 8467: 2018 where the acid number value must be less than 3 mgKOH/g. However, if the measurement uncertainty value is included in the calculation, only the pro analysis grade ethanol solvent has an acid number value that is in accordance with the requirements of SNI. The results of the ANOVA test also showed that there was a significant difference in the variation of ethanol types for determining acid numbers because the calculated F value (13.9004) was greater than the F table (3.0984). Therefore, the solvent that must be used in the method of determining acid numbers in fish oil is pro analysis grade ethanol.

Engine oil oxidation is one of the major reasons for oil aging which can result in variations in the physical and chemical properties of oil. Organic acids generated by oil oxidation can react with water to form inorganic acids and acidic substances (including organic and inorganic acids) that corrode engine parts, resulting in the generation of rust or damage to engine parts. This is one of the important reasons why oil should be regularly changed. One of the most commonly applied methods for judging the aging degree of engine oil is monitoring its acid number (AN). However, generally, the effect of oil water content on acid value measurement is not considered. When oils are used in engines, they are often contaminated by water due to condensation, which accelerates engine oil aging. Therefore, it is crucial to explore the water content effect on AN in the process of engine oil aging. In this research, a water content sensor was applied to characterize moisture content in oxidized oil samples. The sensor could also obtain oil sample electrical conductivity which corresponded to its dielectric constant. Using a mid-infrared spectrometer to measure oil sample AN at this point to obtain the variation in AN with oxidation time, oil sample AN was connected in series with the water content, dielectric constant and electrical conductivity. These parameters were monitored through sensors, and the effect of water content on AN was studied. Experimental results revealed that with the increase in oxidation time, the water content, electrical conductivity, dielectric constant increase and AN of oil were increased. At the same time, since the temperature had a greater effect on electrical conductivity, the application of an air-conditioned constant-temperature environment removed the effect of temperature change on electrical conductivity. [ABSTRACT FROM AUTHOR]

Production of biodiesel from the fat-containing entrails of king crab is investigated. These secondary raw materials are massively disposed (released into the sea) after separation of limbs. Routine technologies of the biodiesel production from vegetable and fish oils are used. The fatty acid composition of the fat is analyzed and the acid and peroxide numbers are determined. A high content of PUFAs (42.5 %) is detected, including the omega-3 (30.6 %) and omega-6 (12.3 %) fatty acids. High acid number (5.5 mg KOH per g fat) and peroxide number (85.6 mmol of active oxygen per g fat) of the crab fat do not meet the requirements for edible fish oils. The biodiesel in the form of fatty acid ethyl esters was produced from the crab fat with three indicators (NaOH, KOH, and H2SO4). Reactions with alkali did not give positive results due to formation of large amounts of soap. The best yield of esters was obtained in the experiment with sulfuric acid: 52.2 g of biodiesel was produced from 50.0 g of fat. Mechanisms of the reaction are explained and mass balances of the process are presented. Kinematic viscosity, total contamination, and acid number of biodiesel (4.96 mm2/s, 8 mg/kg, 0.35 mg KOH/g, respectively) meet the requirements of the national standard GOST R 53605-2009 (EN 14214:2003).

Fire-resistant fluids and lubricants are products that are used in various industry branches for ensuring reliability and safety of equipment operating under conditions of high temperatures and pressures and flame impact. For the last 30–50 years, industry-grade fire-resistant fluids, which feature high thermal stability and do not ignite when coming in contact with flame, have become commercially available in the world market. The article presents the results obtained from long-term studies of such fluids during their operation in the automatic closed loop control systems of steam turbines (STs) of condensing and cogeneration units of thermal power plants (TPPs) located in different regions of Russia and abroad (more than 50 life cycles of these fluids have been analyzed). The reasons for using synthetic compounds in the power industry are described along with the properties in which they differ from petroleum oils, and trends and prospects of applying noncombustible liquids in Europe and Russia are formulated. The aims of the study were to determine the most essential reasons why the standard operation times of fire-resistant fluids were shortened and to develop a procedure for determining the product quality and predicting the life cycle of such fluids (the procedure itself will be addressed in our next publication). Intermediate study objectives were to substantiate the approximation of the input data obtained as a result of their collection and to divide the facilities at which these fluids are used into certain categories. The change in the performance characteristics of fire-resistant fluids during their operation in the control systems of steam turbines of various types at different thermal power plants is analyzed. The most significant factors influencing the extension of fire-resistant fluids' service life are reviewed, and measures aimed at preventing degradation of their quality have been analyzed (regeneration, use of oil purification plants, replenishing, etc.). [ABSTRACT FROM AUTHOR]

In the mid 20th century, type OMTI fire-resistant oil (fire-resistant oil of the thermal engineering institute), whose production technology was developed by specialists of the All-Russian Thermal Engineering Institute (VTI), received wide use at Russian and also at some foreign power plants. Type OMTI oil is distinguished by its high fire-resistant qualities, good lubrication properties, high thermal oxidation and hydrolytic stability, and long service life. Its drawback, as of any phosphorus esters, is sensitivity to the presence of water and increased temperatures, the action of which destructs the fluid with generation of acidic products. This process is "autocatalytic" in nature with a rather quickly reached unacceptable acidic level, at which the replacement of oil may be required. Nowadays, in view of the fact that fire-resistant oils are widely used but have a high cost, matters concerned with supporting the operation of fire-resistant oils and also extending their service life are becoming of much relevance. Another important issue is searching for efficient methods to restore the qualitative characteristics of spent oils that have been accumulated at power industry enterprises with the aim of repeatedly using them as hydraulic fluid or raw material for obtaining new oil. For extending the service life of operating oils and restoring spent oils to the required characteristics, oil purification plants, in which the fluids are subjected to sorption purification and acid destruction products are removed, are required. To ensure the effectiveness of the implemented processes, the sorbent must comply with certain criteria. It should be noted that stable operation of the power industry is essential for the energy security of the state; therefore, it is necessary to commence work on developing the compositions of a new type of fire-resistant oils on the basis of tert-butylphenyls and also elaborating the technology for manufacturing them and estimating the possibility to implement the process at existing industrial chemical sites. The manufacture of the new type of oils must be accompanied by the development of corresponding regulatory documents. [ABSTRACT FROM AUTHOR]

Introduction. During the combustion of diesel fuel in a diesel engine with an increased fuel supply, as a result of its incomplete combustion, soot particles are formed, which are either released into the atmosphere or inevitably enter the engine oil. Soot, polluting the engine oil, causes a change in its quality indicators. Soot is very small particles formed by a complex reaction mechanism in the flame of a fuel-rich region during the combustion of hydrocarbons in the absence of air, mainly consisting of a mixture of amorphous carbon and organic matter.Materials and methods. This paper presents the results of a literary review aimed at studying the ways of soot occurrence during the operation of diesel engines, its effect. The mechanical properties of diesel soot are also discussed on the surfaces of friction pairs and engine components.Conclusions. The soot content in engine oil will increase sharply in engines with exhaust gas recirculation, which leads to an increase in temperature in the friction zones and viscosity of the lubricant, as well as to the formation of deposits on hot parts. These processes occur due to the discharge in the crankcase space and the intensification of the intake of gases from the combustion chamber. Oil change intervals should be monitored at an increased rate of soot entering the engine oil.Scope of the study / opportunity. This type of study will help determine the causes of soot in a diesel engine, understand the consequences of using engine oil contaminated with soot particles.Originality / value. The conducted research can be the basis for the development of recommendations for improving the maintenance of internal combustion engines for enterprises that have cars with diesel engines at their disposal in order to increase the resource of power units and reduce operating costs.

The aim of this study was to determine the peroxide values, acid numbers, oxidative stability (Rancimat method), antioxidant activity (DPPH method), antimicrobial activity (disc diffusion method), sensory properties (9-point hedonic scale), and fatty acid profiles (FAME) of five edible oils purchased from local Slovakian producers—grape seed oil, flax seed oil, walnut oil, poppy seed oil, and milk thistle seed oil. The peroxide value ranged from 2.27 (milk thistle oil) to 8.51 (flax seed oil) mmol O2/kg. All these values were in accordance with regulations (upper limit of 20 mmol O2/kg). The values of the acid number ranged from 0.11 (walnut oil) to 2.49 (milk thistle oil) mg KOH/g, and were in accordance with regulations as they did not exceed the value of 4 mg KOH/g. The oxidation stability was the lowest in flax seed oil (0.18 h) and the highest in grape seed oil (2.05 h). In milk thistle oil, the highest amounts of oleic and behenic acids, in flax seed oil, the highest amount of α-linolenic acid, and in grape seed oil, the highest amount of linolic acid were determined. Antioxidant activity was the strongest in the sample of grape seed oil—65.53 mg TEAC/L (Trolox equivalent antioxidant capacity). Samples of flax seed oil showed the strongest inhibition of Candida albicans CCM 8186 (4.58 mm) and Bacillus subtilis CCM 2010 (0.31 mm). Poppy seed oil was determined to be the most inhibiting towards Klebsiella pneumoniae CCM 2318 (3.68 mm). Milk thistle oil showed the strongest inhibition of Clostridium perfringens CCM 4435 (6.31 mm). Grape seed oil was the most inhibitory towards Staphylococcus aureus subs. aureus CCM 2461 (5.32 mm). Walnut oil showed the strongest activity towards Yersinia enterocolitica CCM 5671 (6.33 mm). The sensory analysis resulted in the samples of walnut and grape seed oil being awarded the highest scores for smell, taste, and overall acceptability. The tested edible oils are rich in biologically active compounds with antioxidant and antimicrobial activities. Their consumption can have a positive effect on the functioning of the human body and its health. Proper storage conditions are, however, necessary because of the susceptibility of these oils to oxidation.

The leather tanning industry is one of the most polluting industries because it generates a gigantic amount of solid, liquid, and gaseous waste. Solid wastes are raw trimmings, fleshings, chrome shavings, buffing clouds of dust, and keratin wastes. Flesh wastes are generated from tanneries during leather processing, especially in sheep liming. These skin-flesh wastes from tanneries contain significant fat content, which is being wasted and dumped in open areas or at dumping sites. As a result, this flesh waste disposal has created a major environmental problem. This research aims to extract a sustainable functional substance that can be used for imparting aesthetic properties (polishing) to a leather product. In this research, a calculated amount of flesh waste was washed, de-limed, and cut into small pieces for solvent extraction of fat using the Soxhlet apparatus and hexane as solvent. Chemical analysis of the extracted fat showed a saponification value ranging from 189 to 192. These values indicate that extracted fat has a triglyceride, which can be used as a lubricant. However, when the extracted fat was applied to leather products like shoes, the surface showed an increase in their aesthetic properties (lustre, and gloss) giving excellent polishing results. The acid and saponification value, fat content, melting point, density, and viscosity of extracted fat showed stability making it a promising substance to impart functionality for leather products and usage as a polishing material. The extracted fat could replace synthetic, functional, and polishing materials overcoming the environmental challenges posed by the leather tanning process.

Cheesemaking is a complex process that involves lactose metabolism, proteolysis and lipolysis. The flavor bouquet of ripening cheeses is formed as a result of changes in all the components of milk. The conditions of keeping and feeding a ruminant, its type, breed, as well as the technological features of cheese production influence this process. Milk fat contributes to the formation of the flavor bouquet of cheese, which undergoes separate changes in the stage of milk processing for cheese. We studied semi-hard cheeses — Dutch and Vityaz and hard cheese — Italiko, made from the same raw milk using the microflora characteristic of these cheeses. The temperature of the second heating ranged from 39°C to 54°C, depending on the type of cheese. To assess the quality of cheeses, their physical and chemical composition and degree of maturity, organoleptic indicators and the content of volatile flavoring compounds, acid number, Reichert-Meissl number and fatty acid composition of the fatty phase of cheeses were determined. In comparative studies of cheeses, the features of the formation of their quality indicators, due to the composition and manufacturing technology, were revealed. They manifested themselves in the flavor bouquet and texture of the product, as well as in the fatty acid composition of cheeses, confirming the importance of the fat phase in the quality formation of the studied cheeses during their production, ripening and storage. It has been proven that even a slight increase in the acid number of fat during the production of all cheeses contributes to the further transformation of the resulting free fatty acids into volatile flavoring compounds that take part in the formation of the taste and aroma of the finished product.

Introduction. The reliability and service life of an engine is largely dependent on the quality of the engine oil. Without oil at the proper level of performance, an internal combustion engine can suffer from wear and tear, which in many cases can lead to engine failure. One of the factors in the loss of the quality level of engine oil is its contamination. For example, kinematic viscosity will gradually increase as the engine oil becomes contaminated with soot, dirt and sludge; or it may be oxidized. If the viscosity of the engine oil is too high, the engine must do extra work to overcome the increased viscosity resistance.Fuel and water dilution is one of the most common contaminants in diesel engines.Materials and Methods. The paper presents the results of a study of the combined effect of water and diesel fuel on synthetic engine oil at their various concentrations. The influence evaluation of contaminants on changes in the performance characteristics of the lubricant, such as: kinematic viscosity at 40° C (measurement was carried out on an automatic Stabinger SVM 3000 viscometer), base and acid numbers (values obtained using an automatic Titroline Alpha 20 Plus titrator), as well as concentration measurement elements - indicators of engine oil on an optical emission spectrometer with inductively coupled plasma of the iCAP 7000 series.Conclusions. The presence of contaminants in the engine oil leads to an increase in kinematic viscosity, during the operation of the engine oil, the value of its base number becomes less, and the value of the acid, on the contrary, increases. It is necessary to replace engine oils when the base number decreases by 50% or according to the balance of base and acid numbers.Scope of Study/Opportunity. This type of low temperature performance modelling provides insight into how the oil deteriorates and evaluates the change in oil performance during use.Originality/value. The study can be the basis for developing recommendations for improving the maintenance of internal combustion engines for enterprises that have cars with diesel engines at their disposal in order to increase the resource of power units and reduce operating costs.

The use of alternatives for petroleum-based products is becoming more and more important, especially considering the new and constantly changing geopolitical context, where excessive energy dependence is not desirable. Thus, biodiesel could play an important role in contributing to the implementation of biorefineries, which represent desirable goals in terms of sustainability, green chemistry and the circular economy. However, one challenge related to biodiesel based on vegetable oils is its low oxidative stability, which can alter the properties of these products during storage. To avoid this problem, interesting antioxidants, such as propyl gallate (PG), could be added to biodiesel to allow it to keep its main properties during oxidation. Additionally, monitoring PG content during oxidation is interesting, and the use of voltammetry could be suitable for this purpose. The aim of this work was to assess the effectiveness of PG during cardoon biodiesel oxidation, while monitoring the process through cyclic voltammetry (CV). As a result, it was proven that PG was highly effective, increasing the length of oxidative stability to more than 10 h at low concentrations (600 mg·L−1) and retaining its main properties (viscosity and acidity) during oxidation. Regarding CV, this technique was successfully optimized to determine PG concentration in cardoon biodiesel during oxidation. [ABSTRACT FROM AUTHOR]

Control of the quality of lubricants both in product batches and in the process of operation is an important stage in the maintenance of aviation equipment since the assessment of the physicochemical composition of lubricants and their tribotechnical parameters allows for determining the correct oil and lubricant replacement interval. An analysis of the influence of the intensity of oxidation of aviation oil for axial hinges of helicopter propeller bushings on oil's anti-wear characteristics was made. An increase in temperature to 120 ºC leads to the intensification of oxidation processes. The consequences of oxidation are the increased viscosity of oils due to the polymerization of molecules of the oxidized base of lubricants, the formation of organic acids, lacquer and deposits, as well as the exhaustion of most oil additives. An increase in the kinematic viscosity of aviation oils with a duration of oxidation of 96 hours by 0.7...2.12 mm2/s was established, depending on the package of multifunctional additives to the basic base. The assessment of the increase in the acid number of aviation oils and the formation of resins during the determination of stability against oxidation was made - with a duration of oxidation of 96 hours, the rate of formation of oxidation products depends on the package of multifunctional additives. The change in the micro hardness of the metal surface layers at the increase in the oil acid number was analysed and the weakening mechanisms were determined. The growth of steel wear due to the weakening of the metal surface layers due to the plasticizing effect of oxidation products that are formed during thermomechanical activation in the friction process has been established. During friction, the activated surface of the metal acts as an oxidation catalyst. It is justified to reduce the periodicity of lubricant material quality control during operation, which will ensure increased wear resistance of elements of triboconjugation. [ABSTRACT FROM AUTHOR]

Engine oil oxidation is one of the major reasons for oil aging which can result in variations in the physical and chemical properties of oil. Organic acids generated by oil oxidation can react with water to form inorganic acids and acidic substances (including organic and inorganic acids) that corrode engine parts, resulting in the generation of rust or damage to engine parts. This is one of the important reasons why oil should be regularly changed. One of the most commonly applied methods for judging the aging degree of engine oil is monitoring its acid number (AN). However, generally, the effect of oil water content on acid value measurement is not considered. When oils are used in engines, they are often contaminated by water due to condensation, which accelerates engine oil aging. Therefore, it is crucial to explore the water content effect on AN in the process of engine oil aging. In this research, a water content sensor was applied to characterize moisture content in oxidized oil samples. The sensor could also obtain oil sample electrical conductivity which corresponded to its dielectric constant. Using a mid-infrared spectrometer to measure oil sample AN at this point to obtain the variation in AN with oxidation time, oil sample AN was connected in series with the water content, dielectric constant and electrical conductivity. These parameters were monitored through sensors, and the effect of water content on AN was studied. Experimental results revealed that with the increase in oxidation time, the water content, electrical conductivity, dielectric constant increase and AN of oil were increased. At the same time, since the temperature had a greater effect on electrical conductivity, the application of an air-conditioned constant-temperature environment removed the effect of temperature change on electrical conductivity.

Fourier transform infrared (FTIR) spectroscopy is a well-established primary qualitative screening tool for Condition Monitoring (CM) of in-service lubricants, with three key determinative ASTM methods often used to accept their continued use or condemn them. These include Acid Number (AN), Base Number (BN) and moisture (H2O), all tedious and environmentally problematic titrimetric methods. The latter have been developed into FTIR quantitative methods through the use of targeted stoichiometric reactions to produce infrared-active products readily and accurately quantified. FTIR CM is discussed in the context of these methods, their tribological significance and the basic analytical concepts examined and compared. The evolution of new FTIR qualitative and quantitative methodology is reviewed from its origins in edible oil analysis to the high-throughput analytical FTIR systems used by commercial CM laboratories to produce ASTM-comparable data in lieu of titration. Comparisons of chemometric vs. stoichiometric approaches are made, including implementation, applications, and instrumentation. Commercial implementation and performance of proprietary quantitative FTIR/IR systems are discussed with a focus on the stoichiometric approach. Current developments include generic, manual FTIR methods combining simplicity, universality, and practical environmental benefits in being able to serve as alternatives to titrimetric procedures. A new methodological approach that could unify the three deterministic FTIR methods under a single, IR-active reaction product is also presented.

A new stoichiometric FTIR Base Number (BN) method of significant utility and analytical benefit to the tribology sector has been developed, providing ASTM D4739‐comparable BN results in lieu of titration in a fraction of the time. Thirty‐six new/in‐service oils analysed by both methods were linearly related with a between‐method accuracy of ~±1.0 BN and a within‐FTIR method reproducibility of ~±0.50 BN. Acid pKa differences and the comparative similarity of the FTIR results to HCl titration are discussed, including analytical benefits. It provides a rapid means of producing quality ASTM‐comparable results, taking ~1 min/sample for spectral analysis versus 30–40 min for potentiometric titration. Method protocols are best suited to an open architecture FTIR accessory but can be readily adapted to flow cell equipped FTIRs. As structured, ASTM‐like results are obtained rapidly with a major analytical environmental/maintenance footprint reduction, being ideally suited for in‐service lubricant or research labs analysing 20–50 samples/day. [ABSTRACT FROM AUTHOR]

The article discusses the issue of improving the quality and storage period of feed by replacing the combination of vegetable and animal fats with full-fat soybeans by processing it by the extrusion method. Processing by this method allows achieving the destruction of enzymes that cause the oxidation of fats and at the same time to suppress the development of harmful microflora in the extrudate, which ultimately affects the storage period of the feed. On the basis of the analysis of existing research materials, two methods of increasing the efficiency of the extrusion method of processing due to the rational use of heat, which is released with the extrudate particles at the exit from the extruder, are proposed. In the first method - for mixing and disinfection of other liquid components when obtaining multi-component paste-like mixtures, in the second - for spraying powder components on extrudate particles, which acquire adhesive properties due to the destruction of cells and the release of fats when obtaining multi-component granular mixtures. The research was carried out on the created experimental stand with the appropriate mixing units mounted at the exit from the extruder, and trial batches of mixtures were developed. At the first stage of the study, the effectiveness of extrusion and selected modes for processing full-fat soybeans by assessing the level of urease inactivation was experimentally confirmed, at the second stage, the effectiveness of the proposed methods of heat use was experimentally evaluated by determining the quality of fats and microbiological parameters of mixtures. In particular, the results showed a moderate increase in the acid and peroxide number and a slight increase in microbiological indicators during 3 months, as well as the absence of enteropathogenic strains of E. coli, toxin-producing anaerobes and salmonella in all studied samples. On the basis of the obtained results, the possibility of using the proposed methods in feed production technologies is substantiated. [ABSTRACT FROM AUTHOR]

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Natural antioxidants of plant origin include chemical compounds, extracts, and essential oils isolated from plant raw materials. They are able to inhibit oxidative spoilage in fat-containing foods. The present research featured the antioxidant and in vivo properties of triterpene alcohol botulin, isolated from the bark of Betula pendula Roth., in fat-containing products, e.g., mayonnaise. Experimental samples of mayonnaise were prepared using the Provencal mayonnaise technology: 6 of 0.2% betulin solution was introduced in vegetable oil during emulsification. The control sample contained no betulin. The experiment relied on standard methods to study the sensory, physicochemical, and microbiological properties of mayonnaise samples. Antioxidant activity was calculated as the inverse of the value of the peroxide number. The antioxidant and hepatoprotective properties underwent hysiological and biochemical in vivo tests on certified white male Wistar rats. The research resulted in a new formulation of mayonnaise with triterpenoid botulin, which proved to be a good plant antioxidant as it reduced the values of acid and peroxide numbers. In freshly processed samples, the acid number was 0.013 g/dm3 in the experimental sample and 0.033 g/dm3 in the control. After 60 days of storage, it increased by 1.4 and 2.3 times, respectively. The peroxide number was 8–10 times higher in the control sample during the storage period. Betulin inhibited the oxidation of triacylglycerides. The antioxidant activity of the fresh prototype was 5.00 units and 0.50 units after 60 days. In the control, it was 0.50 and 0.06 units, respectively. In the experimental sample, betulin slowed down the growth rate of microorganisms. In the control sample, the yeast content increased 1.6 times, and mold exceeded the permissible value by 20%. The antioxidant properties of experimental mayonnaise were proven in vivo on a model of acute toxic hepatitis in rats. Based on biochemical studies of animal blood plasma, the use of mayonnaise with betulin improved the antioxidant protection. Betulin had a positive effect on antioxidant enzymes that destroy organic peroxides, e.g., lipid peroxides, which violate the structure of cell membranes.

The use of biolubricants as a replacement for petroleum-based products is becoming more and more important, due to the current global energy and crude oil scenario. Thus, the production of biolubricants (which could take place in biorefineries) should be as efficient as possible, obtaining high-quality products with suitable viscosity or oxidation stability values to compete with oil refineries. One of the ways to produce biolubricants is through double transesterification from vegetable oils, where the role of catalysts (usually homogeneous) is vital, as they can improve the yield of the process. However, they should be removed after the chemical reaction, which is difficult once the biolubricant is obtained. Otherwise, they could act as catalysts during oxidation, contributing to a further decrease in oxidation stability and provoking significant changes. To avoid this, antioxidant addition could be an interesting choice. The aim of this work was to assess TBHQ addition in frying oil biolubricants, monitoring properties such as viscosity, acid number, absorbance or TBHQ content (through voltammetry) during oxidation. TBHQ addition (2114 mg·L−1) kept the main quality parameters during oxidation compared to control samples. In contrast, TBHQ content decreased during oxidation (to 160 mg·L−1), which proved its antioxidant effect. [ABSTRACT FROM AUTHOR]

Natural pine resin, produced from coniferous species with different techniques is a very valuable and ancient biochemical product. It has wide uses in the chemical industry, paper, road paint, plastic, medicine and cosmetic industries. In recent years, legal restrictions all over the world on consumption of synthetic resin lead the industry to biodegradable products. Although there are suitable forests for natural resin production in Turkey, commercial manufacturing and scientific studies on this subject are not at the desired level today. The aim of this study is to examine the effect of different solvent types on the yield and chemical properties of crude wood resin. As a result of the analysis, extraction yields were found between 16% and 22%, and the highest yield was obtained in the ethanol-benzene solvent system. Collaterally to the yield, the highest acid and saponification numbers were found in alcohol-benzene extracts as 174,87 and 180,33 mg KOH /g, respectively. In order to evaluate our national resources and our current potential in crude wood rosin production, more detailed and effective studies should be carried out on the physical and chemical factors that affect the yield and quality of crude wood rosin .

The monitoring and replacement of lubricating oil has an important impact on mechanical equipment. In this study, based on the infrared spectroscopy monitoring method, an acid value index prediction model is established. The support vector machine regression method is used to quantitatively analyze the acid number of the oil sample, which verifies the stability and predictive ability of the quantitative prediction model, and we provide a theoretical basis and practical examples for the online monitoring of oil indicators. In addition, a support vector machine regression model is established by observing the changing law of the spectral absorption peak and selecting the dominant wavelength, and it is compared against the prediction algorithm of the long- and short-term memory network. By comparing the deviation relationship between the predicted value and the real chemical value, the feasibility of the infrared spectroscopy prediction model is verified. The experimental results show that the correlation coefficient between the predicted value of the model and the actual measured value reaches 0.98. This proves that the prediction effect of the prediction model based on the infrared spectrum data and the support vector machine regression method is better than that of the long- and short-term memory network trend prediction model, and the predicted results are reliable. [ABSTRACT FROM AUTHOR]

Currently, in order to ensure fire safety, fire-resistant fluids are used in the electro-hydraulic control systems of high-capacity steam turbines in thermal power plants. In the Soviet Union and some other countries, fire-resistant OMTI oil, which consists of a mixture of trixylenyl phosphates, was used and similar oils have been used since the beginning of the 1990s. The accumulated experience in the use of fire-resistant liquids allows us to conclude that their quality has a significant impact on the reliability of turbine units. Improving the reliability of the oil systems of steam turbines and other thermal mechanical equipment, as well as increasing the service life of turbine oils, is of wide scientific and industrial interest. The results of long-term studies into the quality of fire-resistant liquids during their operation in automatic control systems of steam turbines of power units of combined-cycle plants located in the central and southern parts of Russia are presented. The objectives of this study were to determine the reasons for the decrease in the resource of fire-resistant liquids and the formation of proposals for updating regulatory documents for their use and quality control. The issues of ensuring the regulatory requirements for fire-resistant liquids are considered, the volumes and methods of conducting chemical analyzes of their quality are analyzed, proposals are made to adjust the instructions for operating equipment and the scope of tests, the causes of aging of fire-resistant liquids are determined, and ways to extend their service life are proposed. Based on the production experience of using imported and domestic fire-resistant liquids, conclusions were drawn about the impact of the quality of the original product and the operating mode on the quality of the oil during its operation as well as the importance of informing the responsible services of the operating organization about the compliance of the production process with the requirements of current regulatory documents. [ABSTRACT FROM AUTHOR]

The rate of oilseeds spoilage depends on the storage conditions and the characteristics of the species, including the chemical composition of the seeds. Of the oil crops, sunflower seeds are the most unstable during storage. The quality of the seeds mainly depends on the initial state of the seeds and the method of their storage. Therefore, the purpose of the study was to determine the dynamics humidity changes, the temperature distribution along the height of the sunflower seed mass, the temperature and humidity of the air in the room, and the general susceptibility of sunflower seeds to fungal infections. Temperature and humidity were determined using temperature sensors DS18B20 and humidity HIH-4000-003, which are mounted in the probes. The data were stored on a personal computer. Seed quality indicators were determined according to standard methods. According to research on the process of storing sunflower seeds of the Kulundynets variety in mounds with a height of 4.5±0.3 m in closed buildings (13.01.2018-02.07.2018) it was established that in the presence of initial damage by a fungal infection of 38±0.3%, its growth was observed up to 41±0.3%. The acid value of the sunflower seed mixture practically did not change and was 0.5-0.6 mgKOH/g. Humidity during storage decreased from 9.1% to 7.4%, which is associated with an increase in the temperature of the environment and a decrease in its humidity. In addition to the above, germination energy during storage decreased from 89.0±0.5% to 85.9±0.5%, and germination decreased from 90.5±0.5% to 85.0±0.5%. It has been established that the traditional system of storing sunflower seeds in bulk in banks or in bulk in closed buildings has low costs. However, without periodically carrying out appropriate measures to control the quality of seeds, the condition of the premises and taking into account the loss of mass of the seed mixture, the specified system can lead to large irreparable losses. [ABSTRACT FROM AUTHOR]

The service life of transformers and, as a consequence, of the electric power systems depends largely on the chemical composition and electrical insulating properties of the oil. In this regard, much attention is paid to the control of physical and chemical indicators and operational proper-ties of transformer oils. The aim of this work is to determine the important diagnostic parameters such as the acid number and the tangent of the dielectric loss angle of the transformer oil based on the measured coordinates of the color of the transformer oil. This goal is achieved by the study of the coordinates of the transformer oils chromaticity. For this purpose, a white light source is used, which is a LED with a pumping line of 450 nm and a maximum radiation in the region of 550-560 nm, with radiation in the range from 400 to 800 nm. Sensors 1, 2, 3 allow determining the chromaticity coordinates of the measured source R, G, B (red, green, blue), due to several receivers having spectral characteristics of sensitivity in the corresponding region of the visible spectrum. The most significant result of the work was the establishment of correla-tions between the TM chromaticity coordinatesб their acid number and the tangent of the dielec-tric loss angle of TM. The significance of the results obtained was that the acid number and the tangent of the dielectric loss angle of the transformer oil could be determined by the chromatici-ty coordinates, and hence, by the color of the oil.

The article presents the research results of the antioxidants’ effect of various origins on the storage of dairy products with high-fat content. The quality change of such products was monitored by the oxidation product content. The antioxidants’ effect of natural origin and human-made origin on the change in the peroxide and acid numbers in spreads with food fibers during storage period for 15 and 30 days at a temperature of (20±2) ° C and (0...- 5) °C has been determined. A significant increase in the peroxide number occurs at a temperature of (20±2) °C. It has been established, that after 6 storage days under the given conditions, the indicator for the control sample increases 4 times, while for products with high-fat content with the addition of antioxidants "NovaSOL COF" and "GRINDOX 109" – 1.2 times. On the 12th storage day, the peroxide number in the spread without additives increased by 8.65 times, in the spread with the introduction of the natural flavoring agent "Caraway – elite flavor" – by 7.15, with the antioxidants "NovaSOL COF" and "GRINDOX 109" – by 4.45 and 4 times, respectively. There was a similar trend towards an increase in the acid number for the research samples of products with high-fat content. After 12 storage days, a significant increase in the value of the acid number has been found in the samples of spreads without antioxidants – 13 times, with the introduction of the natural flavoring agent "Caraway – elite flavor" – 7.8 times. Low acid number values are observed in the samples with the addition of the antioxidants "NovaSOL COF" and "GRINDOX 109", in comparison with other spreads. The obtained results are the basis for the development of recommendations for extending the storage life of products with high-fat content.

Introduction. One of the main types of deposits in an internal combustion engine is an emulsion or sludge formed by water, decomposition of fuel residues and solid residues. The sludge usually settles on the colder surfaces of the engine, such as the bottom of the crankcase pan, valve chambers and upper boards. The main problem is that this type of deposits can be collected by the engine oil and transferred to areas such as the oil pump, intake valve or oil channels, where the sludge can interfere with the flow of oil and cause a failure of the lubrication mode. In addition to the disruption in the operation of the above-mentioned systems, the engine oil quality indicators are also undergoing changes for the worse.Materials and methods. To monitor the condition of the engine oil, it is necessary to determine the characteristics of its performance, such as: kinematic viscosity at 40 oC and at 100 oC, acid number, base number and determine the number of elements – indicators of additives and wear products contained in the engine oil. The viscosity was determined using a Stabinger SVM 3000 viscometer. It measures the dynamic viscosity and density of oils and fuels in accordance with ASTM D7042 and automatically calculates the kinematic viscosity, viscosity index and outputs the measurement results. The acid and base numbers were determined using an automatic titrator TitroLine alpha plus, and the presence of indicator elements in engine oil using an inductively coupled plasma optical emission spectrometer of the iCAP 7000 series, designed for analysis and determination of the number of indicator elements in liquid and solid samples.Results. The dynamics of changes in the performance characteristics of the Gazpromneft Diesel Ultra 10W-40 engine oil with an extended replacement interval, which is applicable for equipment operating in severe conditions, depending on the water content in the samples of this lubricant, was analyzed.Conclusion. The consequences that may occur due to water entering the engine oil are indicated.

The regeneration of used flame-resistant turbine oil based on trixylenyl phosphate using alkaline treatment and contact adsorption techniques is reported. The acid number of the used oil was shown to be reduced to the level approved for exploitation. [ABSTRACT FROM AUTHOR]

Double transesterification from vegetable oils could play an important role in biodiesel and biolubricant production, with the possible implementation of biorefineries to replace refineries based on petroleum. The oxidative stability of the original sample will influence the quality of the intermediate and final products, recommending highly stable raw materials or the use of antioxidants to keep quality parameters during storage. The aim of this work was to obtain a stable biolubricant, assessing its production through a double transesterification with methanol and pentaerythritol from high-oleic safflower oil and adding antioxidants, paying attention to quality parameters. Consequently, a biorefinery that produced high-quality products was proposed. In conclusion, high biodiesel and biolubricant yields were obtained (>97 and >94%, respectively) with the following chemical conditions for the latter: FAME/alcohol ratio, 1:0.33; pressure, 260 mmHg; catalyst concentration, 1.0%; temperature, 160 °C. The oxidative stability of biodiesel complied with the standard (10.78 h) due to its high methyl oleate content (exceeding 80%), whereas this parameter was shorter for the biolubricant (2.86 h), possibly due to its molecular structure. Consequently, antioxidant addition was needed, and tert-Butylhydroquinone at low concentration (500 ppm) kept viscosity and acid number of high-oleic safflower biolubricant during oxidation conditions (up to 8 h). However, tannic acid did not keep these properties in biolubricant. In conclusion, by using the right antioxidant, all the products of the proposed biorefinery were stable during oxidizing conditions, making this biorefinery more competitive.

Morete (Mauritia fleuxosa L. f.) is a palm from the Amazon that produces a fruit with a pleasant taste, good nutritional value and a high oil content. The aim of the present research was to study the effect of the heat treatment of the different parts of morete on the performance and fatty acids profile of oil obtained by pressing. A randomized complete block design with three replicates was applied, combining the use of pulp and pulp with fruit rind under different heating conditions before pressing: 45°C for 30 min, 65°C for 20 min and 85°C for 10 min. Also, the oxidative stability of oil was measured using the Oxitest Reactor. Oils with different content of saturated, monounsaturated, and polyunsaturated fatty acids were obtained with oleic acid prevalence. The best treatment was using pulp heated at 85°C for 10 min and pressing, founding a yield of 56.77% oil with 79.80% oleic acid, and oxidation stability of the oil 14.5 months at 21°C was determined, which is the average temperature of the city of El Puyo, Ecuador, where morete was collected. On the other hand, the effect of this temperature prior to extraction on the content of bioactive compounds and the possibility of oxidation of fats must be evaluated. In conclusion, morete is a good source of oil and the heat treatment technology will allow improving extraction, industrializing, and offering an alternative oil for food. [ABSTRACT FROM AUTHOR]

Soya lecithins are leaders in the global lecithin market not only in terms of production, but also in terms of consumption in various sectors of the food industry, due to the uniqueness of their technological and physiologically functional properties. Production of domestic lecithin is increasing rapidly, it has a high export potential. Development of operational methods for controlling their quality using modern analytical instruments that ensure accuracy and reproducibility of the results is relevant today. The most promising methods are the ones for assessing the quality of oilseed raw materials and products of its processing, including lecithins, based on the NMR pulsed method.The aim of the research is to develop a method for determining the acid number (AN) of liquid soya lecithins using a NMR pulsed method. It has been shown that for the development of a method for determining the AN of liquid soya lecithins, it is necessary to carry out special sample preparation of the sample taking into account the parameters specified for soya lecithins, namely, the ratio of the system «soya lecithin - carbon tetrachloride (CCl4) - NaOH solution» should be equal to 1.0: 3.0: 0.6 ( by weight), and the duration of active contacting of the specified system should be at least 1.5 minutes The indicated sample preparation of samples of liquid soya lecithins will allow obtaining accurate and reproducible results of measuring the amplitude of NMR signals of soap protons, which is an analytical parameter characterizing the content of lipids exhibiting acidic properties in lecithin. Method for determining the AN of liquid soya lecithins based on the NMR pulsed method has been developed using the revealed dependence of the analytical parameter on the values of the AN of liquid soya lecithins, which is characterized by a high correlation coefficient (0.9943).

In the article, the basic physical and chemical properties of polymers based on glyphthalic resin are considered. The main advantages and disadvantages are revealed. The areas of application and the main methods for obtaining glyphthalic resins are considered. The research on studying the course of the polycondensation process on the change of acid number during the reaction of obtaining glyphthalic resin of polyatomic alcohol of glycerol and phthalic acid anhydride is carried out. It is revealed that the results of acid number determination during polycondensation can be used for directed regulation of synthesis of alkyd oligomers and their subsequent curing to obtain a polymer with specified properties. The data was obtained that the polymer under study can be further modified to give special properties that extend the area of its application, as well as to ensure the environmental safety of the waste generated during its use. On the basis of the available data, it is concluded that further research of glyphthalic resin is necessary.

Fire-resistant turbine oils on the basis of triaryl phosphate are subjected to hydrolysis with the formation of acids and phenols during operation at power stations in control and lubrication systems of power units. This increases acid number (AN) and leads to the formation of gum deposits on equipment. The process of decreasing AN in waste Reolube OMTI fire-resistant liquids with AN above 1.5 mg KOH/g, using the hydroxyl flor of AV-17-8chS anion resin, was investigated in this work. It has been demonstrated that, on keeping a fire-resistant liquid at a temperature of 70°С for 2 h, its AN can be reduced from 2.67 to 0.03 mg KOH/g. Decreasing the temperature below 60°С drastically reduces the acid neutralization rate. The rate of acid neutralization also drops sharply on a decrease in AN of a fire-resistant liquid and exhaustion of the exchange capacity of the anion resin. This makes unprofitable the neutralization of acids in oils with AN below 0.05 mg KOH/g using ion-exchange resin. The exchange capacity of anion resin also cannot be completely exhausted. Vacuum drying of neutralized oil at 70°С and a residual pressure of 0.01 MPa yields oil with a water content below 0.03%. [ABSTRACT FROM AUTHOR]

The article presents the research results of the antioxidants' effect of various origins on the storage of dairy products with high-fat content. The quality change of such products was monitored by the oxidation product content. The antioxidants' effect of natural origin and human-made origin on the change in the peroxide and acid numbers in spreads with food fibers during storage period for 15 and 30 days at a temperature of (20±2) ° C and (0...- 5) °C has been determined. A significant increase in the peroxide number occurs at a temperature of (20±2) °C. It has been established, that after 6 storage days under the given conditions, the indicator for the control sample increases 4 times, while for products with high-fat content with the addition of antioxidants "NovaSOL COF" and "GRINDOX 109" - 1.2 times. On the 12th storage day, the peroxide number in the spread without additives increased by 8.65 times, in the spread with the introduction of the natural flavoring agent "Caraway - elite flavor" - by 7.15, with the antioxidants "NovaSOL COF" and "GRINDOX 109" - by 4.45 and 4 times, respectively. There was a similar trend towards an increase in the acid number for the research samples of products with high-fat content. After 12 storage days, a significant increase in the value of the acid number has been found in the samples of spreads without antioxidants - 13 times, with the introduction of the natural flavoring agent "Caraway - elite flavor" - 7.8 times. Low acid number values are observed in the samples with the addition of the antioxidants "NovaSOL COF" and "GRINDOX 109", in comparison with other spreads. The obtained results are the basis for the development of recommendations for extending the storage life of products with high-fat content. [ABSTRACT FROM AUTHOR]

Polysorbates (PS) are the most common non-ionic surfactants used in protein formulations. Their degradation has been studied intensively in recent years. Ester bond hydrolysis is one of many pathways of PS degradation that can lead to accumulation of free fatty acids (FFAs) and particle formation. The distribution and quantity of FFAs in PSs impacts directly on product quality. Characterization of input PS is highly relevant, because the initial content of FFAs differs greatly between manufacturers. The purpose of this study was to set up a quick and simple analytical method for the quantitative evaluation of FFAs in PS. The content of FFAs was measured for selected PS 20 and 80, using two methods, 1H nuclear magnetic resonance spectroscopy (1H NMR) and the European pharmacopoeia method for determining acid value (IA). These methods have been evaluated using the method of standard addition and, based on the results, they are interchangeable. It was concluded that 1H NMR is a useful tool for quality control of input PS and a rapid method for indicating the rate of PS degradation by hydrolysis and oxidation. Further, a newly discovered impurity in PS raw material, the long chain ketone 12-tricosanone, can be identified using 1H NMR.

Introduction. The effective operation of cars largely depends on the state of the engines, their downtime in maintenance and repair. Since the maintenance of modern engines is often reduced to the replacement of engine oil, the increase in the duration of its work significantly reduces maintenance costs and downtime in maintenance. Long maintenance-free operation of the internal combustion engines of automotive vehicles is directly related to the state of the engine oil used in this power unit. The aim of the paper is to show the features of the equipment operation with significant intervals of the engine oils’ replacement in order to increase the efficiency of its usage. The paper presents data on the features of the equipment operation when using high-quality motor oils with extended replacement intervals.Materials and methods. The authors conducted performance tests on the basis of MercedesBenzAxor, MercedesBenzActros cars. The manufacturer provided an estimate of the performance of engine oils. The main performance characteristics of motor oils were assessed using standard methods: kinematic viscosity was measured using a Stabinger viscosimeter, the base number was determined by an automatic AT-500 titrator, the content of wear products was obtained using an ASP-coupled emission spectrophotometer.Results. As a result, the authors presented data on the dependence of the changes in the main indicators of engine oil performance while the operating time and also substantiated the requirements for the volumes of fresh engine oil to compensate losses.Discussion and conclusions. The intermediate control allows detecting faults in the internal car engines, as well as providing the most accurate prediction of the resource of the lubricant under consideration. Therefore, the increasing of the engine oil change interval allows getting a significant economic effect.

Abstrak. Biodiesel terbuat dari minyak nabati melalui proses transesterifikasi. Salah satu faktor untuk memudahkan transesterifikasi adalah penggunaan katalis dalam proses reaksinya. Tujuan dari penelitian ini untuk mengetahui pengaruh penggunaan konsentrasi katalis KOH (0,1%; 0,3%; 0,5%) pada suhu reaksi 450C dengan menggunakan reverse flow biodiesel reactor secara batch. Percobaan pada setiap konsentrasi dilakukan sebanyak 3 kali ulangan. Variabel yang diukur dalam penelitian ini meliputi kualitas biodiesel yang dihasilkan yang terdiri dari: kadar metil ester, angka penyabunan, angka asam, dan gliserol total. Data yang diperoleh kemudian dianalisis dengan analisis deskriptif. Hasil penelitian menunjukkan angka asam, gliserol total pada konsentrasi KOH 0,5% dan angka penyabunan metil ester (biodiesel) memenuhi syarat SNI biodiesel. Kadar metil ester pada masing-masing konsentrasi katalis KOH didapatkan berturut-turut adalah 96,6%, 96,6%, dan 97,5% sehingga memenuhi yang dipersyaratkan dalam SNI-04-7182-2015 yaitu sebesar 96,5%. Study of Using KOH Catalyst on Biodiesel Production Using Reverse Flow Biodiesel Batch Reactor Abstract. Biodiesel is made from vegetable oil through a transesterification process. Presence of catalyst is one of factor to succeed the transesterification process The purpose of this study was to determine the effect of KOH catalyst concentration (0.1%; 0.3%; 0.5%) with reaction temperature 450C by using reverse flow biodiesel batch reactor. Experiments at each concentration were carried out 3 times. The variables measured in this study include the resulting biodiesel quality which consist of: methyl ester content, saponification number, acid number, and total glycerol. Obtained data were then analyzed with descriptive analysis. The results showed the acid number, total glycerol at 0.5% KOH concentration and saponification number fulfilled the SNI biodiesel requirements. Methyl ester contents at each KOH catalyst concentration were obtained 96.6%, 96.6%, and 97.5% respectively, so that it fulfills what is required in SNI-04-7182-2015 which is equal to 96.5%.

Abstract: In this paper, we offer a simple, intuitive, qualitative method for analyzing in diagnosing transformer oils, which does not require expensive equipment and at the initial stage allows us to determine the degree of oil aging.

The monitoring and replacement of lubricating oil has an important impact on mechanical equipment. In this study, based on the infrared spectroscopy monitoring method, an acid value index prediction model is established. The support vector machine regression method is used to quantitatively analyze the acid number of the oil sample, which verifies the stability and predictive ability of the quantitative prediction model, and we provide a theoretical basis and practical examples for the online monitoring of oil indicators. In addition, a support vector machine regression model is established by observing the changing law of the spectral absorption peak and selecting the dominant wavelength, and it is compared against the prediction algorithm of the long- and short-term memory network. By comparing the deviation relationship between the predicted value and the real chemical value, the feasibility of the infrared spectroscopy prediction model is verified. The experimental results show that the correlation coefficient between the predicted value of the model and the actual measured value reaches 0.98. This proves that the prediction effect of the prediction model based on the infrared spectrum data and the support vector machine regression method is better than that of the long- and short-term memory network trend prediction model, and the predicted results are reliable.

The catalytic activity of P- and S-containing acidic carbon materials synthesized from chloromethylene copolymer (HMS) and spherical carbonized resin (SCS) in the transesterification reaction of rapeseed oil with ethanol was studied. It was found that the conversion of oil and the number of by-products of the reaction do not depend on the nature of the introduced heteroatoms. The phosphorus-containing samples of catalysts showed high chemical resistance with their repeated use. [ABSTRACT FROM AUTHOR]