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

Abstract

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 transesterification process with supercritical ethanol.

Densities and Viscosities of Oleic Acid at Atmospheric Pressure

“…Only a brief review and essential information will be given here. The HWD is based on the hydrostatic weighing principle (see also our earlier publications Sagdeev et al, , , , , , , , , , , ; Usmanov et al, ). The present version of the HWD was modified by immersing the cooler‐screen‐10 (see Fig.…”

“…10028‐81, Moscow, Russia) by using the thermostat “TERMOSTAT TYP TWO” (Poland) (ГОСТ, ). The details of the viscometer construction (viscosity apparatus VPZ‐2 m) and method of measurements used in the present measurements were provided in our earlier publication (Usmanov et al, ). In the present work, we used the same type of viscometer (VPZ‐2 m).…”

“…Comparison of the reference values of viscometer calibrating liquids used in our laboratory and those used by other authors confirmed the uncertainty of the viscosity measurements stated by the manufacturer for (VPZ‐2 m). This capillary viscometer (VPZ‐2 m) was also used in our previous work (Usmanov et al, ) for precise measurements of the viscosity of rapeseed oil. These measurements are in good agreement (deviation is within 3.5%) with the data reported by other authors (Anand et al, ; Balat, ; Khubatkhuzin et al, ; Maksimuk et al, ; Noureddini et al, ; see Usmanov et al, ).…”

“…As part of continuing studies (Sagdeev et al, , , , , , ; Usmanov et al, ) of the effect of temperature and pressure on the thermophysical properties of working fluids, the density and viscosity measurements were made for oleic acid, using a modified hydrostatic weighing densimeter (HWD), over a wide temperature range at atmospheric pressure. The HWD was used in our previous publications for accurate measurements of the density and viscosity of pure liquids (Sagdeev et al, , , , , , , , , ) and liquid mixtures (Sagdeev et al, , , , , , ) at temperatures from (273.15 to 413.15) K and at pressures up to 140 MPa.…”

“…The kinematic viscosity of the same oleic acid samples was measured at temperatures from (293 to 365) K using the capillary viscometer (VPZ‐2 m). This viscometer was used in our earlier work (Usmanov et al, ) to measure kinematic viscosity of biodiesel fuel. Measured densities together with kinematic viscosities were used to calculate dynamic viscosities.…”