Viscosity estimation of triacylglycerols and of some vegetable oils, based on their triacylglycerol composition

Density Straight vegetable oil Diesel engine Combustion a b s t r a c tThe straight use of vegetable oils as fuel in diesel engines entails adjusting several physical properties such as density and viscosity. By adequately heating the vegetable oil before entering the injection system, its physical parameters can reach values very close to that of diesel fuel. Consequently, by properly adjusting the temperature of vegetable oils used as fuel, it is possible to improve their combustion performance, thus avoiding premature engine aging due to incomplete burning. In this study the density and viscosity of several vegetable oils are studied within a wide variety of temperatures. The optimal range of temperatures at which each vegetable oil should operate in order to adjust its properties to those of automotive diesel and biodiesel is then found. Additionally an empirical relationship between the dependence of viscosity with density is presented. Thus, by means of the above-described relationship, through measuring the density of a given oil, its viscosity can be directly deduced.ª 2012 Elsevier Ltd. All rights reserved. IntroductionDiesel engines are being extensively utilized worldwide due to their high economic advantage and durability [1,2]. They have appealing features including robustness, high torque, and lower fuel consumption under certain conditions. According to Moron et al. [3] they are prevalent in sectors such as road and train transport, agriculture, military, construction, mining, maritime propulsion and stationary electricity production. Diesel engines can use several fuel types, including diesel fuel, straight vegetable oils (SVO), biodiesel e transesterified vegetable oil e and short chain alcohols. Diesel engines may also function with hybrid fuels, including SVO mixtures in different proportions with diesel or diesel/ ethanol. At the present time there is an increasing demand for energy, concerns about global warming and a growing interest in renewable energy sources; particularly in biofuels [4,5]. This is due to diminishing reserves and price instability of the world's petroleum fuel. These challenges are in part due to the diesel engines themselves. Consequently, it is an urgent matter to reduce hazardous pollutants that diesel engines emit such as NO x , CO, CO 2 and particulate matter (PM). According to Lee at al.[1] this can be achieved by using new combustion technology, by improving fuel characteristics and or by applying after-treatment technology. It is well known that utilizing biofuels with internal combustion engines may contribute to reduce greenhouse gas emissions [6]. Smallscale produced SVOs are considered attractive options for renewable fuel because of environmental benefits [7]. Smallscale use of vegetable oils is also considered an interesting option because they can be obtained from agricultural or industrial sources with very simple processing. This processing includes cold pressing and refining stages that avoid * Corresponding author. Tel.: þ34 938035300; fax: þ34 938031...

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“…Additionally, Azian et al [29] suggested modifying the Equation (4), which is especially useful when dealing with wide temperature ranges,…”

Section: Viscositymentioning

confidence: 99%

Temperature dependence of density and viscosity of vegetable oils

Esteban

Ruiz

Baquero

et al. 2012

Biomass and Bioenergy

319

134

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“…According to Su and White (2004), blending of soybean oil with high‐oleate soybean oil showed a significant effect on color and oxidative stability during frying of bread cubes. Azian et al. (2001) reported that kinematic viscosities of oils and simple and mixed triacylglycerols can be predicted using a modified Andrade‐type equation.…”

Section: Introductionmentioning

confidence: 99%

Impact of Blending of Frying Oils on Viscosity and Heat Transfer Coefficient at Elevated Temperatures

Debnath

Vidyarthi

Singh³

2010

J Food Process Engineering

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In the present work, the effect of binary blending of five frying oils on kinematic viscosity (ν) and convective heat transfer coefficient (h) was studied at elevated temperatures (170, 180 and 190C). A Cannon Ubbelhode calibrated capillary viscometer (Cannon Instrument Company, State College, PA) in a custom‐designed and fabricated convective air bath heater and a highly conductive cylindrical metal transducer were used for generatingνand h data, respectively. The value ofνdecreased from 3.617 × 10‐6 to 2.062 × 10‐6 m2 s‐1, and h increased from 221.0 to 301.2 Wm‐2 C‐1 by increasing the aforementioned oil temperatures. A good correlation betweenν (R2 > 0.996) or h (R2 > 0.987) of these frying oils and their selected binary blends with the previously mentioned temperature range was observed. Significant difference (P < 0.05) was found between different levels of parameters when treatments were compared using Tukey's test. PRACTICAL APPLICATIONS In food engineering applications, the physical properties of foods play an important role in the analysis of process parameters and in the design and fabrication of processing equipment. Determination of kinematic viscosity and convective heat transfer coefficients of frying oils and their selected blends at elevated temperatures are useful from an industrial point of view. In the present work, the effect of blending different edible oils on the kinematic viscosity and convective heat transfer coefficients at elevated temperatures was studied. Because selected blended oils provided lower levels of viscosities and higher levels of heat transfer coefficients, these results may be an attractive proposition in improving the quality of fried products and cost‐effectiveness in the fried food industry.

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“…O primeiro deles considera apenas a composição da mistura e a viscosidade dos componentes puros, e inclui uma aproximação linear (Regra de Kay Simples) e sua forma logarítmica (Regra de Kay Modificada, Azian et al, 2001), apresentadas nas Equações 1 e 2, respectivamente. Como já mencionado, os modelos supramencionados (Equações 1 e 2) requerem o conhecimento da viscosidade de cada composto formador da mistura.…”

Section: Estimativa Das Viscosidadesunclassified

“…Consequentemente, métodos para estimar estas propriedades em diferentes condições são de grande importância prática (Ceriani et al, 2011). A literatura reporta alguns modelos para o cálculo da viscosidade, dentre eles, destacam-se os modelos baseados na fração molar, como a Regra de Kay (Azian et al, 2001), tanto na forma simples como modificada, e o CG-UNIMOD (Cao et al, 1993), que é baseado no conceito de contribuição de grupos.…”

Section: Introductionunclassified

Viscosidades De Misturas Formadas Por Triacilgliceróis, Ácidos Graxos E Alcoóis.

Florido¹,

Lobo²,

Faria³

et al. 2015

Anais Do XX Congresso Brasileiro De Engenharia Química

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RESUMO -Dados de viscosidade permitem aprimorar processos de obtenção e purificação de óleos vegetais utilizando solventes. Devido ao grande número de variáveis que afeta o processo, a aquisição de dados em todas as condições de interesse não é viável e métodos para estimá-las são fundamentais. O objetivo deste trabalho foi testar diferentes modelos preditivos para a viscosidade e compará-los com dados experimentais referentes a sistemas formados por triacilgliceróis (tricaprilina e tricaprina), ácidos graxos (láurico, palmítico e linoleico) e alcoóis de até 6 carbonos (etanol, isopropanol e hexanol). As viscosidades foram obtidas em um viscosímetro automático (Anton Paar). Para a predição dos dados experimentais, foram testadas as formas simples e modificada da Regra de Kay, além do modelo de contribuição de grupos GC-UNIMOD. Os resultados mostraram que, apesar da complexidade das misturas, os modelos mais simples são capazes de fazer uma boa predição da viscosidade, com desvios médios relativos (DMR) inferiores a 7 %, principalmente para misturas com maiores concentrações de solvente, podendo ser uma importante ferramenta para a indústria de óleos e gorduras.

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Viscosity estimation of triacylglycerols and of some vegetable oils, based on their triacylglycerol composition

Cited by 59 publications

References 5 publications

Temperature dependence of density and viscosity of vegetable oils

Temperature dependence of density and viscosity of vegetable oils

Impact of Blending of Frying Oils on Viscosity and Heat Transfer Coefficient at Elevated Temperatures

Viscosidades De Misturas Formadas Por Triacilgliceróis, Ácidos Graxos E Alcoóis.

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