the rhelationship dynamic viscosity on inverse ... - CiteSeerX

Indian J.Sci.Res. 8 (1): 210-213, 2014

ISSN: 0976-2876 (Print) ISSN: 2250-0138(Online)

THE RHELATIONSHIP DYNAMIC VISCOSITY ON INVERSE TEMPERATURE SQUARED FOR SUNFLOWER OIL IOANA STANCIU1 University of Bucharest, Faculty of Chemistry, Department of Physical Chemistry, Bvd. Regina Elisabeta, Bucharest, Romania

ABSTRACT The sunflower oil exhibit positive production trends and show good potential for a variety of industrial applications. The worldwide production of oilseed is increasing day by day, but at present it is costly compared to petroleum based oils. Economic losses are justified when considering the life cycle advantages of vegetable based lubricants. The sunflower oil was investigated using a Haake VT 550 viscometer developing shear rate ranging between 3 and 120 s-1 and measuring viscosity from 104 to 106mPa.s when the HV1 viscosity sensor is used. This article proposes two new relations of dependence of Ln viscosity depending on 1/T2 shear rates between 3.3 and 120s-1. The constants A, B, and C were determined by Origin 6.0 software by fitting linear or polynomial curves obtained from experimental data. The two proposed relationships give correlation coefficients close to one. KEYWORDS: Relationship, Sunflower Oil, Dynamic Viscosity

The sunflower oil exhibit positive production trends and show good potential for a variety of industrial applications. The worldwide production of oilseed is increasing day by day, but at present it is costly compared to petroleum based oils. Economic losses are justified when considering the life cycle advantages of vegetable based lubricants (Dung et al., 2006). From both production and life cycle stand points, the future seems optimistic for sunflower oil as a viable replacement for petroleum based lubricants. In general, when compared with mineral oil base stokes, sunflower oil have the following advantages: higher viscosity index, lower evaporation loss and enhanced lubricity, which leads to improved energy efficiency. However, sunflower oil has performance limitations, particularly in thermal, oxidative and hydrolytic stability (Gamble et al., 1987). Sunflower oil typically contain about 80-95% fatty acids, which are one of the main performance improvers in lubricants (Lajara et al., 1990). On the other hand, mineral oil typically contains saturated aliphatic compounds, namely paraffinic and naphthenic, and small amount of aromatics. Thereby, mineral oils are more stable than sunflower oil through their chemical nature, but they have poorer lubricity (Ramadhas et al., 2005). Sunflower oil are usually excellent boundary lubricants but their high-pressure behavior is not investigated yet properly (Usta et al., 2005). Viscositytemperature relation and density-pressure-temperature relation are important to know the performance of lubricating oil at high-pressure condition. Sunflower oil showed high viscosity index, which is an important property of lubricant (Valdés and Garcia, 2006). The sunflower oil has been proposed several empirical relationships describing the temperature

1

Corresponding author

dependent dynamic viscosity. The more important of these is the Andrade equation (1). Andrade equations are modified versions of equations (2) and (3) (Abolle et al., 2009; Ramadhas et al., 2004; Karaosmanoglu, 1999; Quinchia et al., 2009; Demirbas, 2007): B/T

η=A·10

(1) 2

ln η = A + B/T +C/T ln η = A + B/T +CT

(2) (3)

T is the temperature absolute and A, B and C in the equations (1) to (3) are correlation constants. This article proposes two new relationships of dependence of the Ln viscosity with 1/T2 for sunflower oil. The dynamic viscosity of oils was determined at temperatures and shear rates, the 100°C and the 40°C, respectively, 3.3 to 120s-1. The purpose of this study was to find a linear or polynomial dependence between 1/T2 and Ln viscosity of sunflower oil using Andrade equation changes. Equation constants A, B and C were determined by fitting linear or polynomial.

MATERIALS AND METHODS The sunflower oil used was investigated using a Haake VT 550 viscometer developing shear rate ranging between 3 and 120 s-1 and measuring viscosity from 104 to 106mPa.s when the HV1 viscosity sensor is used. The temperature ranging was from 40 to 1000C and the measurements were made from 10 to 10 degrees. The accuracy of the temperatures was ± 0.1°C.

STANCIU: THE RHELATIONSHIP DYNAMIC VISCOSITY ON INVERSE TEMPERATURE SQUARED FOR SUNFLOWER OIL

RESULTS AND DISCUSSION Figure 1 shows dependence the Ln viscosity on the 1/T2 for studied sunflower oil at shear rate 3.3s-1, 6s1 , 10.6s-1, 17.87s-1, 30s-1, 52.95s-1, 80s-1 and 120s-1.

Figure 3: The dependence ln viscosity on the 1/T2 at 6s-1 for right to C and 1C represents the linear fitting to C Figure 1: The dependence ln viscosity on the 1/T2 at: B – 3.3s-1, C – 6s-1, D – 10.6s-1, E – 17.87s-1, F – 30s-1, G – 52.95s-1, H – 80s-1 and I – 120s-1 This article proposes two (4) and (5) dependency relations of ln viscosity according to the 1/T2 for sunflower oil. We used the computer program Origin 6.0 to determine the constants A, B and C and the correlation coefficients, R. The values of constants A, B and C were determined by fitting linear or polynomial curves obtained for sunflower oil. ln η = A + B/T2 2

(4) 4

ln η = A + B/T + C/T

and

(5)

The dependence of ln viscosity on the 1/T2 for sunflower oil at shear rate 3.3s-1 , 6s-1, 17.87s-1 and 120s1 (the black curves from Fig. 2, 3, 4 and 5) was fitting linear as shown in figures 2, 3, 4 and 5. The linear dependence of ln viscosity on the 1/T2 for sunflower oil at 3.3s-1 is described for equation (4):

Figure 4: The dependence ln viscosity on the 1/T2at 17.87s-1 for right to E and 1E represent the linear fitting to E

ln η = 3.66251 + 0.16136/T2

Figure 5: The dependence ln viscosity on the 1/T2 at 120s-1 for right to I and 1I represents the linear fitting to I

Figure 2: The dependence ln viscosity on the 1/T2 at 3.3s-1 for right to B and 1B represents the linear fitting to

Indian J.Sci.Res. 8 (1): 210-213, 2014

Table 1 shows the value of parameters of the described by equation (4) sunflower oil and correlation coefficient, R. As shown in table 1 the software found it linear equation applied shear rate right of sunflower oil. The root mean square error means that experimental data

STANCIU: THE RHELATIONSHIP DYNAMIC VISCOSITY ON INVERSE TEMPERATURE SQUARED FOR SUNFLOWER OIL

is spread equation. Remains the same temperature range, where the equation was fitted other experimental data. The dependence of ln viscosity on the 1/T2 for sunflower oil at shear rate 6s-1 and 17.87s-1 (the black curves from Fig. 6 and 7) was fitting polynomial as shown in figures 6 and 7. The polynomial dependence of natural logarithm dynamic viscosity on the temperature for sunflower oil at 6s-1 is described for equation (5): ln η = 3.49714+ (-0.17742)/T2 +0.00201/T4

Figure 6: The dependence ln viscosity on the 1/T2 at 6s-1 for curve to C and 1C represents the fitting polynomial to C Table 1: The shear rate, value of parameters of described by equation (4) and coefficient correlation for sunflower oil Shear rate, s-1 3.3 6 10.6 17.87 30 52.95 80 120

Value of parameters of the described by equation (4) A B 3.6625 0.1614 3.3707 0.1402 3.2293 0.1352 3.1599 0.1411 3.1718 0.1449 3.1692 0.1513 3.1161 0.1512 2.4732 0.0615

Correlation coefficient, R2 0.9992 0.9903 0.9839 0.9888 0.9958 0.9992 0.9977 0.9987

Table 2: The shear rate, value of parameters of described by equation (5) and coefficient correlation for sunflower oil Shear rate, s-1 3.3 6 10.6 17.87 30 52.95 80 120

Value of parameters of the described by equation (5) A B C 3.6866 -0.1774 0.0020 3.4971 -0.2245 0.0105 3.3983 -0.2479 0.0141 3.3059 -0.2385 0.0122 3.2521 -0.1985 0.0067 3.1889 -0.1645 0.0017 3.1849 -0.1971 0.0057 2.5028 -0.0768 0.0017

Indian J.Sci.Res. 8 (1): 210-213, 2014

Correlation coefficient, R2 0.9988 0.9974 0.9996 0.9996 0.9980 0.9988 0.9997 0.9991

STANCIU: THE RHELATIONSHIP DYNAMIC VISCOSITY ON INVERSE TEMPERATURE SQUARED FOR SUNFLOWER OIL

Figure 7: The dependence ln viscosity on the 1/T2 at 17.87s-1 for curve to E and 1E represents the fitting polynomial to E Table 2 shows the value of parameters of the described by equation (5) sunflower oil and correlation coefficient, R. As shown in table 2 the software found it polynomial equation applied shear rate right of sunflower oil.

CONCLUSION The dynamic viscosity of sunflower oil was determined at temperatures between 313 and 373K and shear between 3.3s-1 and 120s-1. This article proposes two new relations of dependence of ln viscosity according to the inverse temperature. The values of constants A, B and C and the correlation coefficients were determined by linear and polynomial fitting of the experimental curves using Origin 6.0 software.

REFERENCES Abolle A., Kouakou L., Planche H.; 2009. The viscosity of diesel oil and mixtures with straight vegetable oils: Palm, cabbage palm, cotton, groundnut, copra and sunflower. Biomass and Bioenergy., 33(9): 1116-1121. Demirbas

A.; 2007. Importance of biodiesel as transportation fuel. Energy Policy., 35(9): 4661-4670.

Dung C. H., Wu S. C. and Yen G. C.; 2006. Genotoxicity and oxidative stress of the mutagenic compounds formed in fumes of heated soybean oil, sunflower oil and lard. Toxicology in vitro., 20(4): 439-447. Gamble M. H., Rice P. and Selman J. D.; 1987. Relationship between oil uptake and moisture loss during frying of potato slices from cv Record UK tubers. International Journal of Food Science & Technology., 22(3): 233-241.

Indian J.Sci.Res. 8 (1): 210-213, 2014

Karaosmanoglu F.; 1999. Vegetable oil fuels: review. Energy Sources, 21(3): 221-231.

a

Lajara J. R., Diaz U., Quidiello R. D.; 1990. Definite influence of location and climatic conditions on the fatty acid composition of sunflower seed oil. Journal of the American Oil Chemists’ Society., 67(10): 618-623. Ramadhas A. S, Jayaraj S., Muraleedharan C.; 2004. Use of vegetable oils as IC engine fuels—a review. Renewable energy., 29(5): 727-742. Ramadhas A. S., Muraleedharan C., Jayaraj S.; 2005. Performance and emission evaluation of a diesel engine fueled with methyl esters of rubber seed oil. Renewable energy., 30(12): 1789-1800. Quinchia L. A., Delgado M. A., Valencia C., Franco J. M., Gallegos C.; 2009. Viscosity modification of high-oleic sunflower oil with polymeric additives for the design of new biolubricant formulations. Environmental science & technology., 43(6): 2060-2065. Usta N., Öztürk E., Can Ö., Conkur E. S., Nas S., Con A. H., Topcu M.; 2005. Combustion of biodiesel fuel produced from hazelnut soapstock/waste sunflower oil mixture in a Diesel engine. Energy Conversion and Management., 46(5): 741-755. Valdés

A. F., Garcia A. B.; 2006. A study of the evolution of the physicochemical and structural characteristics of olive and sunflower oils after heating at frying temperatures. Food chemistry., 98(2): 214-219.