Kinematic Viscosity Value Research Articles

Biodiesel production from non-edible oils using immobilized recombinant lipase from Pseudomonas fluorescens isolated in the Western Ghats, India

Lipases, essential enzymes for hydrolyzing triglycerides, are widely produced by various microorganisms, including bacteria, fungi, and yeast. Among microbial lipases, those from Pseudomonas species are particularly notable for their thermal resistance and alkaline activity, making them valuable for industrial applications. This study focuses on a novel recombinant lipase gene from Pseudomonas fluorescens AFPF19, aiming to express this gene in Escherichia coli (E.coli) and evaluate its potential for biodiesel production. The lipase gene was successfully isolated, cloned into the pET28a expression vector, and expressed in E. coli BL21 CodonPlusTM (DE3). The recombinant lipase was purified using Ni-NTA affinity chromatography. To enhance the enzyme’s stability and reusability, immobilization techniques were employed. The immobilized lipase demonstrated robust activity in the transesterification of Millettia pinnata oil to produce biodiesel. Various reaction conditions, including oil-to-methanol molar ratios and enzyme concentrations, were optimized to maximize biodiesel yield. Gas chromatography-mass spectrometry (GC-MS) analysis confirmed the high purity of the produced biodiesel, while its properties, such as density, kinematic viscosity, and calorific value, met international standards. This study highlights the potential of using immobilized recombinant lipases for sustainable and efficient biodiesel production, addressing challenges associated with free enzyme use and contributing to the advancement of renewable energy sources.

Prediction of the Kinematic Viscosity of Libyan Crude Oil as a Function of its Specific Gravity as One Input Data

The prediction of the kinematic viscosity of some Libyan crude oils based on its specific gravity as one input parameter has been investigated. The correlation was developed in order to improve on the accuracy of existing correlations and to assist oil kinematic viscosity where the knowledge of viscosity of uncharacterized crude oils is required. The data used to build the correlation consist of measurements from 4 crude oils from various locations around Libya, the range from 0.81 to 0.84 g/cm3, resulting in kinematic viscosity values ranging from 5 – 11 mm2/s. The correlation can be used as far as the specific gravities’ values are available. When a single specific gravity measurement is available at 15oC, it can predict the viscosity at 40 oC with an average absolute deviation (AAD) of 6.58%, which is an improvement in accuracy compared to previously published correlations (Puttagunta) with the kinematic viscosity at 37.8 as one input for kinematic viscosity prediction was 7.17%. Finally, when a t-test which is an inferential statistic used to determine if there is a significant difference between the means of experimental and theoretical data of kinematic viscosity, the difference was considered to be not statistically significant. It is worth noting that the required input for this equation is only the specific gravity.

Producing and Testing the Properties of Biodiesel Sourced from Hemp Oil

Organic matter is converted into a variety of fuels, including potential replacements for transport fuels. New sources of raw materials are being sought for their acquisition. One such raw material that is currently attracting a growing degree of attention is hemp. The objective of this study was to produce biodiesel from hemp oil to ascertain its selected properties and to compare them with the properties of biodiesel obtained from rapeseed oil and the properties of diesel fuel. A reactor designed for the non-industrial, local conversion of available raw materials into fatty acid esters was used for the manufacture of biodiesel. The properties of hemp oil biodiesel were evaluated in comparison with those of rapeseed oil biodiesel, with properties of diesel fuel, and with the requirements set forth in the EN 14214 standard, pertaining to the specification of fatty acid methyl esters for utilization in compression-ignition internal combustion engines. The kinematic viscosity value of the hemp oil biodiesel yielded just below the upper limit defined in the standard. Furthermore, research has demonstrated that such biodiesel contains a considerable proportion of esters of linoleic and linolenic acids, which are susceptible to oxidation. The content of linolenic acid ester in esters produced from hemp oil is clearly higher than the content of this ester in esters obtained from rapeseed oil. This higher content contributes to the high value of the iodine number, significantly exceeding the standard requirements. The remaining designated properties of hemp oil biodiesel are in accordance with the requirements laid down in the standard and exhibit similarities to those of rapeseed oil biodiesel. Further research is recommended to enhance the characteristics of hemp oil biodiesel and its utilization in compression-ignition engines.

Evaluating Biodiesel Properties from Waste Cooking Oil for Sustainable Energy Applications

Biodiesel was synthesized from used vegetable oils collected from local restaurants in Minna, Niger State, Nigeria, using a base-catalyzed transesterification process with methanol and potassium methoxide as the catalyst. The physicochemical properties of the produced biodiesel, such as density, kinematic viscosity, flash point, pour point, cetane number, and calorific value, were evaluated and compared against conventional diesel fuels and biodiesel from other sources like Jatropha, Neem, and Castor oils. Gas chromatography (GC) was used to analyze the fatty acid methyl esters (FAMEs) composition, identifying methyl oleate, methyl linoleate, methyl palmitate, and methyl stearate as the primary components. The produced biodiesel exhibited favourable properties, including a cetane number and flash point within recommended ASTM standards, indicating efficient ignition and safe storage characteristics. Additionally, the calorific value and kinematic viscosity of the biodiesel were found to be comparable to conventional diesel, making it a viable blend for diesel engine applications.

Effect of Ultrasonic Waves on Aspire Biodiesel and Comparison of Its Properties with Petroleum Diesel

This study aimed to determine the effect of ultrasonic sound waves on modifying the chemical structure of biodiesel to bring its physical properties closer to petroleum diesel. In this direction, safflower oil was selected because its fatty acid composition is similar to fatty acid esters of petroleum diesel and is a sustainable source. Refined safflower oil, the free fatty acid content of which was determined, was reacted with methanol under NaOH catalyst to perform the transesterification reaction. After biodiesel production, samples were incubated in an ultrasonic bath for 60, 120, and 180 minutes. FTIR, density, free fatty acid content, flash point, viscosity, and cloud point analyses investigated the effect of incubation times on biodiesel's chemical structure and properties. FTIR spectra showed that ultrasonic sound waves partially decomposed fatty acid methyl esters and increased the number of volatile components in biodiesel. The flash point of biodiesel has been associated with a decrease of 89°C, and the low flash point is expected to increase fuel efficiency. Kinematic viscosity values were measured in the 3.4583-3.5115 mm²/s range, and density values were measured in the 0.8820-0.8872 g/ml range. These values show that biodiesel complies with national and international standards. As a result, the ultrasonic bath process applied to biodiesel showed a similar result to chemical modification methods by affecting the structure of fatty acid chains. Thus, it brought the physical properties of biodiesel closer to petroleum diesel. It is seen that this method is a more efficient alternative for biodiesel production because it does not use additional chemicals, and the process is faster. In conclusion, by increasing the production of the drought-resistant safflower plant, sustainable energy resources will be contributed, while its waste can be evaluated as animal feed. Ultrasonicated safflower biodiesel can also be used as an efficient, environmentally and mechanically friendly alternative fuel source.

Method of Detecting Liquid Meniscus in Capillary Using Ultraviolet Sensor

The accuracy of determining the physical and chemical properties of a liquid, in particular, assessing the viscosity of the liquid used, is considered an important technical problem in medicine, food, oil, chemical industries, as well as in other areas that determine the quality and safety of human life and activity. For example, assessing the viscosity of the liquid used is a key stage in the design of hydraulic systems. Today, the improvement of methods for determining the viscosity of a liquid is on the path to automation (digitalization) of measurement instruments and methods. In this area, the activities of metrologists and engineers are consistent with the national program «Digital Economy of the Russian Federation» adopted in 2017. The article discusses the capillary method for determining the kinematic viscosity of a liquid as the most accurate of all possible methods at present. The method is based on determining the time of liquid flow between two marks, which are applied to the walls of a glass capillary viscometer forming a measuring tank. One of the main problems of this method is that all stages of measurement are performed by a person, even recording the moment when the liquid meniscus crosses the mark, which is a violation of one of the key principles of process automation – independence of execution, which only implies monitoring the operation of the system. Since ready-made solutions do not fit the laboratory’s measurement tasks, the management decided to develop and conduct a study of an information and measuring system that will carry out the process of detecting the liquid meniscus at the mark level, as well as recalculate the measured time interval into the kinematic viscosity value. The key decision in this development is the choice of a sensor for detecting the liquid meniscus. Based on the literature review, it was decided to use a photoelectric sensor. A study of the transmission spectra of liquids used in this method was conducted to select the wavelength at which the sensor will operate. Thus, a type of photoelectric sensor designed to operate in the UV range has been selected to automate the method of detecting the liquid meniscus when it crosses a mark applied to a capillary tube. The article is addressed to metrologists who perform verification and calibration of glass capillary viscometers, specialists in the field of experimental and theoretical viscometry. The method proposed by the authors can become the basis for further improvement of the method for measuring the kinematic viscosity of a liquid.

Analytical Method for Determining the Viscosity Index of Engine Lubricating Oils

This paper proposes a simple analytical method for determining the viscosity index (VI) that effectively aligns with results obtained from the applicable standards. This method simply needs the kinematic viscosity of the tested oil at 40 and 100 °C as input parameters and does not need to use tables that are an integral part of the mentioned standards. This work presents a method and evaluates the accuracy of determining auxiliary parameters in the form of kinematic viscosity values at 40 °C for two hypothetical oils. These oils have a kinematic viscosity at 100 °C equal to that of the oil under testing and have VI = 0 and 100. The relative fitting error percentage and the coefficient of determination are found for the specified auxiliary indicators. The method is validated using data obtained from previous studies in the form of the kinematic viscosity of lubricating oil–diesel mixtures. The mixtures of viscosity grades SAE 30 and SAE 40 lubricating oil with diesel oil at concentrations of 0, 1, 2, 5, 10, 20, and 50% w/w are tested. The viscosity index for each mixture is determined using a standard-based manual calculation using the Anton Paar viscosity index calculator and the proposed method. The results obtained from the proposed analytical method are compared with those from two other methods. The maximum percentage relative fitting error (δmax ≈ 1%) and the coefficient of determination (R2 > 0.999) are determined. The obtained results demonstrate a very good fit and, thus, confirm the usefulness of the proposed approach.

Influence of Solid Alkaline Photocatalysts Irradiated with UV Light on Fuel Properties of Palm Oil Biodiesel.

TiO2 nanoparticles are full of porosity that can be impregnated with a strong alkaline catalyst CH3ONa to form a TiO2/CH3ONa catalyst. TiO2 of the anatase phase, which is a semiconductor material, has been a prominent photocatalyst due to its excited photocatalyst activity, chemical and biological stability, and nontoxicity. The CH3ONa compound has been widely used as a catalyst for transesterification. Although the synthesized photocatalyst TiO2 powder with CH3ONa is anticipated to greatly enhance the transesterification efficiency, leading to improving biodiesel properties, relevant studies have not been found. After the photocatalyst was prepared, a reactant mixture of palm oil, methanol, and heterogeneous catalyst TiO2/CH3ONa was illuminated by ultraviolet (UV) light from light-emitting diode (LED) lamps. The experimental results revealed that the formation of fatty acid methyl esters was significantly increased to 98.4% with ultraviolet-light illumination for the molar ratio of methanol/palm oil equal to 6 and 3 wt % catalyst addition. The decrease of the catalyst amount to 2 wt % resulted in a slight decrease of the fatty acid methyl esters to 97.06 wt %. The lowest kinematic viscosity and acid value and the highest distillation temperature, heating value, and cetane index were observed under the above reaction conditions. The distillation temperature and cetane index were increased while the acid value was decreased under ultraviolet illumination on the reactant mixture. Consequently, the optimum preparing conditions for biodiesel production were 6 and 3 wt % for the molar ratio of methanol/palm oil and catalyst addition under UV-light irradiation.

Synthesis of bio-based nanolubricant using bimetallic nanoparticles to mitigate the surface deterioration of low carbon steel for metalforming industry

Worldwide industries are drawing their attention to the usage of bio-based substances for their operational purposes. Herein, the bimetallic nanoparticles (Bi-MNPs) were synthesised using a unique combination of Zn–Cr in bio-based mustard oil by green route utilizing wet chemical approach. Synthesised Bi-MNPs (0.12–0.15 wt%) were employed in the synthesis of bimetallic bio-based nanolubricant (Bi-BNL), and the impact was also evaluated on low carbon steel (grade SAE1006). The reduction of Bi-MNPs was carried out by green reducing agents and their stabilisation was confirmed by Fourier transform infrared spectroscopy (FTIR). Whereas, the synthesis of Bi-MNPs was followed by Surface plasma resonance (SPR), average size of Bi-MNPs which was about 60 nm and morphology was established using Scanning electron microscopy (SEM). The efficiency of Bi-BNL and impact of Bi-MNPs on the stability of Bi-BNL was investigated by Dynamic light scattering (DLS), Zeta potential (ZP) and comparative study was carried out with reference lubricant. Interestingly, the kinematic viscosity (KV) values of the lubricants are quite compatible, and have linear relationsip with coefficient of friction which is very suitable to conclude the anti-friction and anti-wearing properties. The KV of bio-based oil was monitored under the criteria of standard test method ASTM D445, and the resultant value was compared with the reference oil. The stability of Bi-BNL and its interaction with low carbon metal sheet was also studied; the outcomes were very impressive due to no rust patches, oil spots and surface deterioration on the metal sheet. The paramount creativity of this research work is the modification of bio-based oil via Bi-MNPs for the synthesis of Bi-BNL that offers the best surface quality of low-carbon steel. Cumulatively, these findings of Bi-BNL could be open up new possibilities to explore the bio-based synthesis of lubricants on a comprehensive scale.

Methyl Ester Production from Rice Bran Oil and Methanol with Calcium Carbonate Catalysts Using Esterification Method

Rice bran oil is a type of oil with high nutritional value from rice bran. However, the free fatty acid content in it can increase by more than 60% with sufficient storage time. Free fatty acids contained in rice bran have the potential to be produced into biodiesel (methyl ester). This research aimed to determine the effect of methanol volume and esterification process time on biodiesel yield and to compare methyl ester yield to standard biodiesel. This research was conducted in two stages, namely rice bran oil extraction and esterification. In the extraction stage, rice bran was extracted with n-hexane for 3 hours at an operating temperature of 65oC. The esterification process was carried out by mixing rice bran oil, methanol with a certain volume (100, 125, 150, 175, 200 mL), and calcium carbonate catalyst as much as 1% of the amount of methanol. Esterification was carried out with time variations of 1; 1.5; 2; 2.5 and 3 hours. The results in the form of rice bran oil were analyzed for the value of the biodiesel yield. The result of rice bran oil was analyzed for initial free fatty acid value. Pure biodiesel product in the form of methyl ester was obtained through separation with glycerol as a by-product. The optimum methyl ester yield was 81.70% at 175 ml methanol volume for 3 hours. The methyl ester results are in accordance with SNI biodiesel for density and kinematic viscosity values.

Collective dynamics of liquid sulphur across the polymerisation transition temperature probed by inelastic x-ray scattering

Inelastic x-ray scattering (IXS) experiments on liquid sulphur were carried out below (140 ∘C) and above (180 ∘C) the polymerisation temperature T λ of about 159 ∘C to investigate changes in the collective dynamics of this unique liquid, that exhibits a liquid–liquid transition. As reported earlier, broad longitudinal acoustic excitation signals were observed at both temperatures, and only the width of the quasielastic peaks slightly decreased when the temperature crossed the transition temperature. A model analysis was performed using a generalised Langevin formalism with a memory function having one thermal and two viscoelastic decay channels with the help of simple sparse modelling, and large positive deviations from the hydrodynamic sound velocity by 51%–54% were observed. The fast viscoelastic relaxation time τ µ is close to the correlation times of intermolecular stretching and bending motions of local sulphur connections in both ring and chain structures, and is similar to those of other molecular liquids. The small contrasts in the IXS spectra across the λ transition result in large changes in only the slow viscoelastic decay time τ α of the memory function. The τ α value at 140 ∘C matches the mixed internal/external torsional modes of S8 molecules well, whereas that at 180 ∘C has no corresponding molecular motion mode. The kinematic viscosity values at the Q→0 limit are much smaller than the minimum values of macroscopic shear viscosity, indicating that large changes in relaxation dynamics are expected with Q in the GHz and MHz excitation regimes.

Spectroscopy-Based Machine Learning Approach to Predict Engine Fuel Properties of Biodiesel

<div>Various feedstocks can be employed for biodiesel production, leading to considerable variation in composition and engine fuel characteristics. Using biodiesels originating from diverse feedstocks introduces notable variations in engine characteristics. Therefore, it is imperative to scrutinize the composition and properties of biodiesel before deployment in engines, a task facilitated by predictive models. Additionally, the international commercialization of biodiesel fuel is contingent upon stringent regulations. The traditional experimental measurement of biodiesel properties is laborious and expensive, necessitating skilled personnel. Predictive models offer an alternative approach by estimating biodiesel properties without depending on experimental measurements. This research is centered on building models that correlate mid-infrared spectra of biodiesel and critical fuel properties, encompassing kinematic viscosity, cetane number, and calorific value. The novelty of this investigation lies in exploring the suitability of support vector machine (SVM) regression, a burgeoning machine learning algorithm, for developing these models. Hyperparameter optimization for the SVM models was conducted using the grid search method, Bayesian optimization, and gray wolf optimization algorithms. The resultant SVM models exhibited a noteworthy reduction in mean absolute percentage error (MAPE) for the prediction of biodiesel viscosity (3.1%), cetane number (3%), and calorific value (2.1%). SVM regression, thus, emerges as a proficient machine learning algorithm capable of establishing correlations between the mid-infrared spectra of biodiesel and its properties, facilitating the reliable prediction of biodiesel characteristics.</div>

Biodiesel production and exploring properties of Datura stramonium L. oil with its optimization using combined approaches-Taguchi, grey relational analysis, and response surface methodology.

Biodiesel production through the synthesis of Datura stramonium L. oil is studied to explore the most efficient approaches to suggest an alternate feedstock for biodiesel production. The main objective of this work is to optimize the process variables of biodiesel synthesis by using some statistical approach (Taguchi method, grey relational analysis (GRA), and response surface methodology (RSM) analyzing three parameters, i.e., alcohol-to-oil molar ratio, catalyst (NaOH) concentration, and process temperature for achieving maximum biodiesel derived from Datura stramonium L. oil. The transesterification process is applied by using an ultrasonic-assisted technique. Grey relational analysis (GRA) was successfully applied with the Taguchi method resulting in the optimum combination of A2B1C1. Based on the findings, the best operating conditions for transesterifying are attained with the RSM approach consisting of a 5.697:1 molar ratio (level 2), 0.3 (wt.%) NaOH concentration (level 1), and 70 °C process temperature (level 1). With a value of 87.02%, these ideal operating conditions produce the maximum yield as compared to grey relational analysis (GRA) yields 83.99%. The obtained results have been verified through the characterization of oil and biodiesel as well. Also, the fuel qualities of DSL biodiesel were identified and assessed. DSL oil was found 137.6 degrees of unsaturation during fatty acid profile analysis. DSL biodiesel was found the best kinematic viscosity (4.2 mm2/s) and acid value (0.49) when compared to Karanja and palm biodiesel. D. stramonium L. was recognized as a suitable species for biodiesel feedstock according to the findings.

Synthesis and characterization of biodiesel obtained from castor oil transesterification

The objectives of this work were to optimize the variables affecting transesterification process for biodiesel production from castor oil, non edible oil, by acid catalysis (sulphuric and phosphoric acid) and basic catalysis (potassium methoxide and potassium hydroxide); and to characterize the biodiesel for its use as fuel in compression ignition motors. The studied operation variables were methanol/oil molar ratio (3:1, 6:1, 9:1, 12:1), temperature (25, 35, 45, 55, 65 ºC), and catalyst amount (2, 3, 4 wt.% in acid catalysis, and 0.5, 1.0, 1.5 wt.% in basic catalysis). Evolution of each process was followed by gas chromatography, determining the content of methyl esters at different reaction times. Biodiesel was characterized by a set of parameter according to European Standard, EN 14214. The best conditions for transesterification process were 9:1 methanol/oil molar ratio, 65 ºC, and the use of potassium methoxide as catalyst with concentration 1.0 wt.%. In these conditions, obtained biodiesel presents satisfactory values of water content, iodine and saponification values, flash and combustion points, and temperature of 50% of distillate. However, values of density, kinematic viscosity, cetane index and cold filter plugging point, that are heavily dependent on oil, move away from those required by the European Standard.

Recycled waste groundnut oil: A potential feedstock for green energy/biodiesel synthesis

This work focuses on the recycling of waste groundnut oil as a potential feedstock for biodiesel production using activated coconut husk as a regenerating agent. The coconut husk was functionalized using organic acid. The properties of the functionalized coconut husk were investigated via instrumental analysis. Non-parametric modeling involving 2-degree isotherm models were used. The regeneration/recycling of the waste oil were done in batch mode examining key factors of temperature, time, concentration and dosage. Biodiesel was synthesized from recycled waste groundnut oil using transesterification reaction. The properties of biodiesel were examined using ASTM and AOAC official standards. Brunauer-Emmett-Teller surface analysis revealed the surface area of the adsorbent as 371.88 m2/g and a porosity distribution of 0.567 η on the surface at a pH of 6.1. Batch mode analysis revealed that 97.5% of impurities was removed from waste groundnut oil under one batch process at 80 °C after 4 h with 6 g of the activated coconut husk. Langmuir isotherm model provided the best fit to the experimental data with adsorption capacity of 33.5 mg/g at R2 of 0.996. Adsorption of waste groundnut oil impurities onto activated coconut husk was endothermic, as evidenced by the calculated ΔH of +2.7914 kJ/mol. A high cetane number of 48.4 obtained after transesterification is an indication of the good ignition quality of the obtained recycled waste groundnut oil methyl ester. Kinematic viscosity and acid value were revealed to be 4.65 mm2 S−1 and 0.31 mg KOH/g, while the calorific value stood at 38,053 kJ/kg. GC-MS analysis revealed a complex mixture of fatty acid methyl esters dominated by unsaturated fatty acids (58.78%). Recycling of waste cooking oil in this work using activated coconut husk demonstrated good quality as a regenerating agent. The properties of biodiesel obtained showed that it has all the good qualities comparable to other existing biodiesel based on the ASTM and AOAC official standards. More work on the recycling of other waste cooking oils for green energy synthesis to protect our environment from pollution emanating from the use of conventional petro-diesel and promote energy transition is highly recommended.

Development of high free fatty acid crude palm oil as a biodegradable electrical liquid insulator as an alternative to mineral oil-based insulators

Mineral-based oil is now often used for transformer oil. Unfortunately, this kind of oil is harmful and unfriendly to the environment, necessitating the use of vegetable-based products that are both ecologically benign and biodegradable. With its properties, crude palm oil (CPO) might be a possibility for a vegetable-based insulator. Concerning it, the goal of this study was to create a method for converting CPO into an insulator that fulfilled IEC 62770 requirements. The researchers created a CPO-based insulator using degumming, filtration, distillation, and a vacuum drying technique in their work. At vacuum pressures ranging from 15% to 65% vacuum and temperatures ranging from 150 °C to 200 °C, 0.05% phosphoric acid, 5% bleaching earth, and 10% zeolite were used in the degumming process. The best measurement results showed that the values of breakdown voltage and kinematic viscosity of 60 kV and 12.7 cSt, respectively, met the requirements. The moisture content was higher than the required value, while the acid content was still relatively high, namely 1.4 mg KOH/g, thus requiring further treatment. After treatment using 2% KOH, the acidity became 0.01 mg KOH/g, and the moisture content was 176 ppm thus meeting the requirement. The color of the insulator produced was light yellow, bright, and clear. The best treatment parameter combination found was a pressure of 51.9% vacuum with a temperature of 168.7 °C. This research showed that the vacuum pressure had a significant effect on moisture, kinematic viscosity, and acidity, while temperature had a significant effect on breakdown voltage and acidity.

Feasibility Studies of Treated Used Cooking Palm Oil as Precursor for Bio-Lubricant

The non-renewability and and non-biodegradability of petroleum based lubricants as well as the environmental impacts their waste contributes to the environment has caused the search for a substitute for precursor of lubricant formulation. The food security issue has caused major concerns on how vegetable oil could replace petroleum based product lubricants. This paper reports the feasibility studies of kinematic viscosity, friction and wear properties of treated used cooking palm oil as precursor for development of new bio-lubricant. The treated used cooking palm oil displayed a comparable value of kinematic viscosity of 43.6cSt, coefficient of friction of 0.126 and 122µm which is almost similar to the value of fresh cooking palm oil. Treated used cooking palm oil is seen to be a suitable candidate for precursor of bio-lubricant formulation, However, some additives may need to be added as to increase the tribological properties for treated used cooking oil to be used as a bio-lubricant.

A study of kinematic viscosity approach with air as a gas medium for turbine flowmeter calibration

Calibrating a gas flowmeter requires a suitable working medium that represent its use in the real operating condition. However, factors like installation conditions, costs, and safety considerations may necessitate to utilize a different medium for calibration. The accuracy of measuring fluid flow by a flowmeter is greatly influenced by the kinematic viscosity property of the gas medium. In this particular study, a turbine flowmeter for compressed natural gas (CNG) application was calibrated using air as a substitute with an approach that simulated the kinematic viscosity property of CNG. Here, the pressure and temperature of the air were calculated to achieve the same kinematic viscosity value as CNG during the calibration process, which was accomplished by adjusting the setting of a regulating instrument in the calibration installation. Furthermore, argon (Ar) was also used for comparison with air, with a modification in working pressure to attain similar kinematic viscosity properties for both gases. The calculation results showed that the working pressure setting for the air used was 4.5 bars, while for argon was 3.38 bars to achieve similar kinematic viscosity. By utilizing air instead of CNG, a minimum and maximum volume flowrate difference of −0.0242 m3/h and 0.0016 m3/h, respectively, was observed, with an absolute average of 0.0086 m3/h or 0.8 %. This study reveals the effectiveness of the kinematic viscosity approach in calibrating a turbine flowmeter under working pressure of up to 4.5 barg. This process results in uncertainty measurement of under 1 % when calibrating gas flowmeters, using air as the medium.

Influence of blending cycloalkanes on the energy content, density, and viscosity of Jet-A

This work focuses on the influence of addingvarious cyclohexanes on the volumetric and gravimetric energy content, density, and kinematic viscosity of Jet A. Mixtures of Jet-A and alkylcyclohexanes with varying alkyl-chain lengths, degrees of branching, and number of rings at 5, 10, 15, 30, and 60 % wt./wt. were examined. Among the alkylcyclohexanes under study, addition of the compounds with the longest alkyl chains, i.e., n-hexylcyclohexane and n-heptylcyclohexane, were identified as compounds with the potential to increase both the specific and energy density of the mixtures. Contrasting results obtained for 1,2,3-trimethylcyclohexane (decreasing specific energy and increasing density) and 1,3,5-trimethylcyclohexane (decreasing energy density and kinematic viscosity) revealed the importance of the relative position of the substituents in cycloalkanes. More sterically hindered isomers and less symmetrical structures were associated to higher density and kinematic viscosity values. C9-cycloalkanes were identified as potential molecules to decrease the kinematic viscosity of blending mixtures. Branched structures in C12-cycloalkanes, such as 1,3-diisopropylcyclohexane and 1,4-diisopropylcyclohexane, were found to decrease gravimetric energy. However, additions higher than 15 % wt./wt. of branched cycloalkanes were also associated with increments of the volumetric energy content to values similar when linear alkyl-chain cycloalkanes of the same carbon number were added into the mixture. Decalin withcis-stereochemistry exhibited greater energy density, density, and kinematic viscosity thantrans-stereochemistry. JP-10 additions provided slightly higher energy densities but lower specific energies thancis-decalin. At low mass additions (<10 % wt./wt.), tricyclic compounds, such as tetradecahydroanthracene and adamantane, caused the largest increases in the energy density and density of the mixtures. Tetradecahydroanthracene increased the specific energy by +0.26 % and the volumetric energy by +1.40 % when added at 5 and 10 % wt./wt., respectively. However, larger mass additions (>10 % wt./wt.) of adamantane into Jet-A are not possible due to solubility conditions. Additions of JP-10 (28 % wt./wt.), cis-decalin (40 % wt./wt.), or trans-decalin (50 % wt./wt.) into Jet-A are proposed to maximize energy content (∼+3.5 %) while meeting density and kinematic viscosity requirements. These results broaden the understanding of cycloalkanes as potential key compoundsof sustainable aviation fuels withhigher energy content and minimal environmental impact.

Standard diesel production from mixed waste plastics through thermal pyrolysis and vacuum distillation

Plastic pyrolysis oil (PPO) was produced in a pilot-scale batch pyrolysis reactor at 540 °C from mixed waste plastic (MWP) (high-density polyethylene (HDPE), polypropylene (PP) and polystyrene (PS)). The produced PPO was then distilled in a vacuum distillation unit and diesel was obtained at temperatures between 170 and 380 °C along with light petrol (<170 °C) and heavy residue (>380 °C). This study found that MWP can produce over 80% liquid oils without operational problems or wax formation. Distilled PPO produces 49.5–53% diesel, 39 – 46.5% petrol and residue 1.5 – 8% by weight. Although PPO has calorific value ranging from 43.85 to 45.26 MJ/kg like commercial diesel however, PPO is not suitable for direct use in diesel engine for low kinematic viscosity (KV) and density values at 1.1–1.26 mm2/s and 0.78 – 0.83 gm/cm3 respectively. For the distilled diesel cut (DC), KV, density, higher heating value (HHV), cetane index (CI), aromatic hydrocarbon (AH) and poli-aromatic hydrocarbon (PAH) were found 1.95–2.15 mm2/s, 0.81 – 0.85 gm/cm3, 44.92–46.36 MJ/kg, 46 – 58, 18.81 – 35.1% and 4.81 – 11.9% respectively indicating better option for direct use as automobile diesel with significant effect of HDPE amount present in feedstock.