Kinematic Viscosity Measurements Research Articles

Lubricity of ethanol–diesel blends – Study with the HFRR method

Due to increasing fuel consumption in various industries, especially in road transport, interest in increasing the market participation of renewable fuels is growing. One such fuel is ethanol. The raw materials for its production include sugar beets, sugar cane, potatoes and many other starch-containing plants. Ethanol can be used as a pure fuel in positive-ignition engines that have undergone relatively minor technical modifications. However, in compression-ignition engines, due to factors such as a very low cetane number and lubricity, ethanol cannot be used as a pure fuel. Therefore, increasing attention is being paid to fuel consisting of blends of diesel fuel with certain concentrations of ethanol. Diesel fuel containing up to 15% (v/v) ethanol is sometimes referred to as e-diesel or oxygenated diesel. In this paper, the lubricity of blends of conventional diesel fuel and ethanol, with ethanol content up to 14% (v/v), were tested. The HFRR (High-Frequency Reciprocating Rig) method was used for the research, which is a normative method of determining the lubricity of diesel fuel. For individual fuel samples, microscopic photographs of wear scar caused on test balls, along with the designation of areas that have been considered when measuring the diameters of wear scars, were presented. The obtained values of WSD (Wear Scar Diameter) were compared to the regulatory requirements for diesel fuels. Further measurements of kinematic viscosity, density and water content were conducted for individual fuel samples. The results showed that in the range of up to 14% (v/v), the proportion of ethanol in diesel fuel causes hardly any changes to its lubricity as determined by HFRR, and in addition, diesel fuel with up to 14% (v/v) added ethanol still meets the standard requirements in terms of lubricity.

Note: A portable automatic capillary viscometer for transparent and opaque liquids.

A portable automatic capillary viscometer, equipped with an AVR microcontroller, was designed and developed. The viscometer was calibrated with Certified Reference Material (CRM) s200 and utilized for measurement of kinematic viscosity. A quadratic equation was developed for calibration of the instrument at various temperatures. Also, a model was developed for viscosity determination in terms of the viscometer dimensions. Development of the portable viscometer provides for on-site monitoring of engine oil viscosity.

A Laboratory Study of the Effects of Wide Range Temperature on the Properties of Biodiesel Produced from Various Waste Vegetable Oils

Biodiesel is an attractive alternative fuel for diesel engines produced from vegetable oils or animal fats by transesterification in the presence of a catalyst. The feedstocks used in this experiment for the production of biodiesel were waste frying oil (WFME) waste canola oil (WCME), and their different percentages are referred to as 25-WFME, 50-WFME and 75-WFME. The samples are sourced from Northern Cyprus. Also, biodiesel was produced at Mechanical Engineering research laboratory. The purpose of this study is to investigate the effect of the temperature on the kinematic, dynamic viscosity and density of the biodiesel samples. Also, this paper examines the cold flow properties as well as the kinematic viscosity, cloud point (CP) and pour point (PP) of the produced biodiesel. The density, kinematic viscosity, CP and PP measurements were made according to ASTM standards. The properties of the produced biodiesel such as viscosity and density were measured within temperature ranges 20–270 °C in steps of 10 °C. The kinematic viscosity, CP and PP were measured within temperature range −10–20 °C. In this study, five general correlations were presented for estimating the density and kinematic viscosity of the blends at several temperatures. The experimental investigation showed that CP and PP of WCME increased with an increase in the concentration of WFME. Furthermore, empirical equations for predicting the viscosity, density, CP and PP for biodiesel samples give values in good agreement with experiments. The results obtained show that with the increase of the temperature, kinematic viscosity, dynamic viscosity and density decreased.

Rheoviscosimetric Study of Poly(N-isopropylacrylamide) in Water and in the Solvent Mixture (Water-Ethanol), Evidence of High Huggin’s Coefficient

This paper presents a rheoviscosimetric study of a thermo-sensitive polymer, poly(N-isopropyl acrylamide) PNIPA, with weight average mass Mw = 17774 Daltons whose LCST is 32 °C. The concentration regimes in water are identified. As solvent, we first used ultra pure water then we added an organic co-solvent (ethanol) with a mass up to 20%. Under shear, the dynamic viscosity of a PNIPA solution with water as solvent versus temperature increases from a critical temperature Tmin very close to the LCST until reaching a maximum at Tmax. Kinematic viscosity measurements do not show this increase in viscosity. It is believed that by deforming the chains of the polymer and bringing the hydrophobic end groups (isopropyl) each other, the shearing causes the formation of aggregates through an inter-chain association at the time of activation of the hydrophobicity of isopropyl groups at ~ 32 °C. The authors found that the gradual addition of ethanol decreases the quality of the solvent; the intrinsic viscosity shows a decrease in the volume occupied by the chain in the solvent mixture. The Huggins coefficient kH confirms this trend by largely positive values in zone I in the presence of ethanol, therefore the authors believe that two contributions (hydrodynamic and Brownian motion) can explain the highness of kH.

Viscosity, density, and thermal conductivity of aluminum oxide and zinc oxide nanolubricants

This paper presents liquid kinematic viscosity, density, and thermal conductivity measurements of eleven different synthetic polyolester-based nanoparticle nanolubricants (dispersions) at atmospheric pressure over the temperature range 288 K to 318 K. Aluminum oxide (Al2O3) and zinc oxide (ZnO) nanoparticles with nominal diameters of 127 nm and 135 nm, respectively, were investigated. A good dispersion of the spherical and non-spherical nanoparticles in the lubricant was maintained with a surfactant. Viscosity, density, and thermal conductivity measurements were made for the neat lubricant along with eleven nanolubricants with differing nanoparticle and surfactant mass fractions. Existing models were used to predict kinematic viscosity (±20%), thermal conductivity (±1%), and specific volume (±6%) of the nanolubricant as a function of temperature, nanoparticle mass fraction, surfactant mass fraction, and nanoparticle diameter. The liquid viscosity, density and thermal conductivity were shown to increase with respect to increasing nanoparticle mass fraction.

Characterization of water content in biodiesel fuel certified reference material (NMIJ CRM 8302-a)

The National Metrology Institute of Japan has issued a certified reference material of biodiesel fuel derived from palm oil (NMIJ CRM 8302-a) for the measurement and quality control of water, methanol, six elements (sulfur, phosphorus, sodium, potassium, magnesium, and calcium), density, and kinematic viscosity. This paper presents the technical details for the characterization of the water content in NMIJ CRM 8302-a. Because the water content in biodiesel is easily affected by ambient humidity, sample handling is extremely difficult. Thus, a sample handling technique that overcomes this limitation was established, and optimized coulometric and volumetric Karl Fischer titrations were performed in order to accurately determine the water content with traceability to the International System of Units. The certified water content and its expanded uncertainty with a coverage factor k = 2 were 393 mg kg−1 and 25 mg kg−1, respectively.

Formation of κ-carrageenan–gelatin polyelectrolyte complexes studied by 1H NMR, UV spectroscopy and kinematic viscosity measurements

The intermolecular interactions between an anionic polysaccharide from the red algae κ-carrageenan and a gelatin polypeptide, forming stoichiometric polysaccharide–polypeptide (bio)polyelectrolyte complexes in the aqueous phase, were examined. The major method of investigation was high-resolution 1H NMR spectroscopy. Additional data were obtained by UV absorption spectroscopy, light scattering dispersion and capillary viscometry. Experimental data were interpreted in terms of the changing roles of electrostatic interactions, hydrophobic interactions and hydrogen bonds when κ-carrageenan–gelatin complexes are formed. At high temperatures, when biopolymer macromolecules in solution are in the state of random coil, hydrophobic interactions make a major contribution to complex stabilization. At the temperature of gelatin’s coil→helix conformational transition and at lower temperatures, electrostatic interactions and hydrogen bonds play a defining role in complex formation. A proposed model of the κ-carrageenan–gelatin complex is discussed.

The Effect of Fatty Acid Ethyl Esters Concentration on the Kinematic Viscosity of Biodiesel Fuel

Several biodiesel fuel samples produced from rapeseed oil by the noncatalyzed transesterification reaction with supercritical ethanol at various temperatures from (593 to 653) K and molar ethanol to rapeseed oil ratios from (6:1 to 20:1) were used to measure kinematic viscosity. Measurements were made using the capillary viscometer (VPZ-2, Labtex Com., Moscow). The combined expanded uncertainty of the kinematic viscosity measurements at the 95 % confidence level with a coverage factor of k = 2 is estimated to be 0.35 %. All measurements were made at temperature of 313.5 K (ASTM D445) and at atmospheric pressure. The effect of fatty acid ethyl esters (FAEEs) content on the kinematic viscosity of biodiesel fuel samples at 313.15 K was studied. The correlation between the FAEEs concentration in biodiesel fuel samples and their measured kinematic viscosity at 313.15 K was found. The derived correlation between the kinematic viscosity and the FAEEs contents allows controlling the progress of the rapeseed oil t...

Quality metrics for elaborated aqueous fire extinguishing substance on base of copper(ii) chloride

Research results relating to the measurement of kinematic viscosity, surface tension, density, acidity and other quality metrics (consistence, freezing point, etc.) for recently elaborated aqueous fire extinguishing substance (AFES) made up of 40% aqueous solution of copper(II) chloride with added different amounts of surface-active substance are presented in this article.

Molecular interactions and solubilization of structurally related meso-porphyrin photosensitizers by amphiphilic block copolymers (Pluronics)

The influence of four Pluronics block copolymers (i.e. F68, P123, F127, and L44) on the aggregation and solubilization of five structurally related meso-tetraphenyl porphyrin photosensitizers (PS) as model compounds for use in Photodynamic Therapy of cancer (PDT) was evaluated. Interactions between the PSs and Pluronics were studied at micromolar concentration by means of UV-Vis absorption spectrometry and by kinematic viscosity (υ) and osmolarity measurements at millimolar concentrations. Pluronic micelles were characterized by size and zeta potential (ζ) measurements. The morphology of selected PS-Pluronic assemblies was studied by atomic force microscopy (AFM). While hydrophobic 5,10,15,20-Tetrakis(4-hydroxyphenyl) porphine (THPP) seemed to be solubilized in the Pluronic micellar cores, amphiphilic di(monoethanolammonium) meso-tetraphenyl porphine disulphonate (TPPS2a) was likely bound to the micellar palisade layer. Hydrophilic PSs like 5,10,15,20-Tetrakis (4-trimethylaniliniumphenyl) porphine (TAPP) seemed to form complexes with Pluronic unimers and to be distributed among the micellar coronas. TPPS2a aggregated into a network which could be broken at Pluronic concentration ≫ cmc, but would reconstitute in the presence of tonicity adjusting agents, e.g. sodium chloride (NaCl) or glucose.

Vegetable oil-based ionic liquid microemulsions and their potential as alternative renewable biolubricant basestocks

This paper reports the successful formulation of microemulsions with vegetable oil as the continuous phase, room-temperature ionic liquid (IL) 1-butyl-3-methyl-imidazolium tetrafluoroborate as the polar phase, TritonX-100 as the surfactant, and 1-butanol as the cosurfactant. A pseudo-ternary phase diagram, dynamic light scattering data, UV–vis spectra, and kinematic viscosity measurements were employed to characterize and analyze the phase behavior and microstructure of the vegetable oil-based IL microemulsions. The tribological properties of the designed microemulsions were evaluated using a four-ball tester. The results confirmed the formation of an IL microemulsion containing vegetable oil. The designed petroleum-free microemulsions exhibit excellent viscosity-temperature characteristics and friction–reduction proprieties, indicating the tremendous potential of IL microemulsions as renewable biolubricant basestocks.

Effects of Monoacylglycerols on Kinematic Viscosity and Cold Filter Plugging Point of Biodiesel

AbstractBiodiesel is an alternative fuel composed of mono‐alkyl fatty acid esters made from the transesterification of plant oils or animal fats with methanol or ethanol. After conversion, biodiesel may contain trace concentrations of unconverted monoacylglycerols (MAG). These MAG have low solubility in biodiesel and may form solid residues when stored at cold temperatures. The present study evaluates the measurement of kinematic viscosity (ν) and cold filter plugging point (CFPP)‐time to filter (Δt) as parameters that predict the temperature where small concentrations of MAG may lead to formation of solids or other phase transitions that restrict the flow of soybean oil fatty acid methyl esters (SME) through filters and fuel lines. Mixtures of SME doped with MAG were prepared and ν and Δt were measured as the temperature decreased from 20 to below 0 °C. Results showed a correlation between ν and Δt that held for neat SME (SME without added MAG) and SME‐MAG mixtures as the temperature decreased to the threshold temperature (Tth). Sharp increases in Δt disrupted the correlation as temperature decreased below Tth. Furthermore, Tth generally increased as added MAG concentration increased in the mixtures.

Viscosity and density of aluminum oxide nanolubricant

This paper presents liquid kinematic viscosity and density measurements of a synthetic polyolester-based aluminum oxide (Al2O3) nanoparticle dispersion (nanolubricant) at atmospheric pressure over the temperature range 288 K–318 K. Two Al2O3 particles diameters were investigated: approximately 60 nm and 10 nm. A good dispersion of the spherical nanoparticles in the lubricant was maintained with a surfactant. Viscosity and density measurements were made for the neat lubricant along with twelve nanolubricants with differing nanoparticle and surfactant mass fractions. A new model was developed to predict the kinematic viscosity of the nanolubricant by summing the viscosities of the nanoparticle, the surfactant and the base lubricant. The resulting correlated model for the liquid kinematic viscosity was a function of temperature, nanoparticle mass fraction, surfactant mass fraction, and nanoparticle diameter. The measurements are important for the design of nanolubricants for heat transfer and flow applications.

Viscosity and density of CuO nanolubricant

This paper presents liquid kinematic viscosity and density measurements of a synthetic polyolester based copper (II) oxide (CuO) nanoparticle dispersion (nanolubricant) at atmospheric pressure for a temperature range from approximately 288 K to 318 K. The polyolester was a commercially available chiller lubricant. The CuO particles were approximately 30 nm diameter, spherical, and well dispersed in the lubricant. Viscosity and density measurements were made for the pure base lubricant along with three nanolubricants with differing nanoparticle mass fractions (2.9%, 5.6% and 39.2%). The viscosity and the density were shown to increase with respect to increasing nanoparticle mass fraction. Correlations of the viscosity and the density are presented as a function of temperature and nanoparticle concentration. The measurements are important for the design of nanolubricants for heat transfer and flow applications.

Results of the IEA Round Robin on Viscosity and Stability of Fast Pyrolysis Bio-oils

An international round robin study of the stability of fast pyrolysis bio-oil was undertaken. Fifteen laboratories in five different countries contributed. Two bio-oil samples were distributed to the laboratories for stability testing and further analysis. The stability test was defined in a method provided with the bio-oil samples. Viscosity measurement was a key input. The change in viscosity of a sealed sample of bio-oil held for 24 h at 80 °C was the defining element of stability. Subsequent analyses included ultimate analysis, density, moisture, ash, filterable solids, and TAN/pH determination, and gel permeation chromatography. The results showed that kinematic viscosity measurement was more generally conducted and more reproducibly performed versus dynamic viscosity measurement. The variation in the results of the stability test was great and a number of reasons for the variation were identified. The subsequent analyses proved to be at the level of reproducibility, as found in earlier round robins on bio-oil analysis. Clearly, the analyses were more straightforward and reproducible with a bio-oil sample low in filterable solids (0.2%), compared to one with a higher (2%) solids loading. These results can be helpful in setting standards for use of bio-oil, which is just coming into the marketplace.

Viscosity Arrhenius Activation Energy and Derived Partial Molar Properties in 1,4-Dioxane + Water Binary Mixtures from 293.15 to 323.15 K

The knowledge and prediction of physicochemical properties of binary liquid mixtures is of great importance for understanding intermolecular interactions. Viscosities (η) have been investigated by using density (ρ) and kinematic viscosity (ν) measurements for 1,4-dioxane + water (D–W) mixtures over the entire range of mole fractions under atmospheric pressure, at 311.15, 316.15 and 320.15 K, in order to increase the studied temperatures range available from the literature and to improve the investigations. The viscosity Arrhenius activation energy of 1,4-dioxane + water mixtures was calculated from the present experimental viscosity measurements, and those presented in a previous work at only four temperatures, and for three temperatures in the present work, over the entire range of composition in the temperatures range from 293.15 to 323.15 K. Based on the partial molar activation energy from the Arrhenius equation for viscosity, interactions between water and 1,4-dioxane molecules are discussed. Comparison between some reduced Redlich–Kister functions covering the composition domain shows the existence of two distinct behaviors.

Measurement of Bunker Oil / DME Blended Fuel Viscosity for Diesel Engine Application

Currently, around 80% of large ships use Bunker oil (JIS C heavy oil) as the base fuel in marine diesel engines. With its very high kinematic viscosity, this oil is considered the lowest grade of fossil fuel. Thus, it needs to be heated to reduce its viscosity. The authors have reported that the blending of liquefied DME improved the combustion performance of Marine Diesel Oil (JIS A heavy oil). This study aims to clarify the effectiveness of DME – Bunker oil blends. The kinematic viscosity measurement of DME and Bunker oil blended fuel was performed using a capillary tube type viscometer. A pressure cell which contains the viscometer was developed to measure the fuel viscosity while keeping DME in a liquid state. From experiments, it was shown that the cell pressurization resulted in smaller values of kinematic viscosity, and modification was needed to obtain true viscosity values. It was shown that at 323K, the kinematic viscosity of Bunker oil can be reduced drastically from 54~89% with DME blending.

Thermal stability of sewage sludge pyrolysis oil

The stability of the oil phase obtained from intermediate pyrolysis process was used for this investigation. The analysis was based on standard methods of determining kinematic viscosity, gas – chromatography / mass - spectrometry for compositional changes, FT-IR for functional group, Karl Fischer titration for water content and bomb calorimeter for higher heating values. The methods were used to determine changes that occurred during ageing. The temperatures used for thermal testing were 60 ˚C and 80 ˚C for the periods of 72 and 168 h. Methanol and biodiesel were used as solvents for the analysis. The bio-oil samples contained 10 % methanol, 10 % Biodiesel, 20 % Biodiesel and unstabilised pyrolysis oil. The tests carried out at 80 ˚C showed drastic changes compared to those at 60 ˚C. The bio-oil samples containing 20 % biodiesel proved to be more stable than those with 10 % methanol. The unstabilised pyrolysis oil showed the greatest changes in viscosity, composition change and highest increase in water content. The measurement of kinematic viscosity and gas chromatograph mass spectrometry were found to be more reliable for predicting the ageing process.

Viscosity of molten lithium, thorium and beryllium fluorides mixtures

Considering development of Molten Salt Fast Reactor (MSFR) concept, following Molten Salt fluorides mixtures have been chosen as an object for viscosity studies in this work (in mol%): 78LiF–22ThF 4; 71LiF–27ThF 4–2BeF 2 and 75LiF–20ThF 4–5BeF 2. Additionally, the effect of the 3 mol% CeF 3 additives on viscosity of the molten 75LiF–20ThF 4–5BeF 2 (mol%) salt mixture has been investigated experimentally. The method of torsional oscillations of cylindrical crucible filled by molten fluorides mixture has been chosen for kinematic viscosity measurement at temperatures up to 800–850 °C. In temperature ranges, where melts behave as normal liquids, dependences on viscosity vs. temperature are received: ν = А exp [B/T(K)], where ν – kinematic viscosity, m 2/s; T – temperature, K. The kinematic viscosity Rout mean squares (RMS) estimated in the assumption about dispersion homoscedasticity is (0.04–0.12) × 10 −6 (m 2/s). Discrepancies left in the data of viscosity for molten mixtures of LiF, BeF 2 and ThF 4 received by different researchers need further investigations in this area to be continued.

Competition between Redlich–Kister and improved Herráez equations of correlation viscosities in 1,4-dioxane +water binary mixtures at different temperatures

Viscosity deviation Δη has been investigated by using density and kinematic viscosity measurements for dioxane + water mixtures over the entire range of mole fractions at atmospheric pressure and in five temperatures (293.15, 298.15, 302.15, 306.15 and 309.15 K). This system exhibited very large positive values of due to increased hydrogen bounding interactions between unlike molecules in the cluster formation region and to very large differences between the molar volumes of the pure components. The results were fitted with the Redlich–Kister equations and the recently proposed Herráez equation. This last model was improved by fixing the first constant of the corresponding exponential function. Competition between the two models at different parameter numbers is discussed. We note that, in this system, where the viscosity versus molar fraction of dioxane presents a maximum, experimental data are in agreement with the two models when more than three parameters are employed.