White Mustard (Sinapis alba L.) Oil in Biodiesel Production: A Review.

White mustard (Sinapis alba L.) seed oil is used for cooking, food preservation, body and hair revitalization, biodiesel production, and as a diesel fuel additive and alternative biofuel. This review focuses on biodiesel production from white mustard seed oil as a feedstock. The review starts by outlining the botany and cultivation of white mustard plants, seed harvest, drying and storage, and seed oil composition and properties. This is followed by white mustard seed pretreatments (shelling, preheating, and grinding) and processing techniques for oil recovery (pressing, solvent extraction, and steam distillation) from whole seeds, ground seed or kernels, and press cake. Novel technologies, such as aqueous, enzyme-assisted aqueous, supercritical CO2, and ultrasound-assisted solvent extraction, are also discussed. The main part of the review considers biodiesel production from white mustard seed oil, including fuel properties and performance. The economic, environmental, social, and human health risk/toxicological impacts of white mustard-based biodiesel production and use are also discussed.

Optimization and kinetic modeling of esterification of the oil obtained from waste plum stones as a pretreatment step in biodiesel production.

This study reports on the use of oil obtained from waste plum stones as a low-cost feedstock for biodiesel production. Because of high free fatty acid (FFA) level (15.8%), the oil was processed through the two-step process including esterification of FFA and methanolysis of the esterified oil catalyzed by H2SO4 and CaO, respectively. Esterification was optimized by response surface methodology combined with a central composite design. The second-order polynomial equation predicted the lowest acid value of 0.53mgKOH/g under the following optimal reaction conditions: the methanol:oil molar ratio of 8.5:1, the catalyst amount of 2% and the reaction temperature of 45°C. The predicted acid value agreed with the experimental acid value (0.47mgKOH/g). The kinetics of FFA esterification was described by the irreversible pseudo first-order reaction rate law. The apparent kinetic constant was correlated with the initial methanol and catalyst concentrations and reaction temperature. The activation energy of the esterification reaction slightly decreased from 13.23 to 11.55kJ/mol with increasing the catalyst concentration from 0.049 to 0.172mol/dm(3). In the second step, the esterified oil reacted with methanol (methanol:oil molar ratio of 9:1) in the presence of CaO (5% to the oil mass) at 60°C. The properties of the obtained biodiesel were within the EN 14214 standard limits. Hence, waste plum stones might be valuable raw material for obtaining fatty oil for the use as alternative feedstock in biodiesel production.

Kinetic modeling and optimization of maceration and ultrasound-extraction of resinoid from the aerial parts of white lady's bedstraw (Galium mollugo L.).

In this paper, extraction of resinoid from the aerial parts of white lady's bedstraw (Galium mollugo L.) using an aqueous ethanol solution (50% by volume) was studied at different temperatures in the absence and the presence of ultrasound. This study indicated that ultrasound-assisted extraction was effective for extracting the resinoid and gave better resinoid yields at lower extraction temperature and in much shorter time than the maceration. A phenomenological model was developed for modeling the kinetics of the extraction process. The model successfully describes the two-step extraction consisting of washing followed by diffusion of extractable substances and shows that ultrasound influences only the first step. The extraction process was optimized using response surface methodology (RMS) and artificial neural network (ANN) models. For the former modeling, the second-order polynomial equation was applied, while the second one was performed by an ANN-GA combination. The high coefficient of determination and the low MRPD between the ANN prediction and the corresponding experimental data proved that modeling the extraction process in the absence and the presence of ultrasound using ANN was more accurate than RSM modeling. The optimum extraction temperature was determined to be 80 and 40 °C, respectively for the maceration and the ultrasound-assisted extraction, ensuring the highest resinoid yield of 22.0 g/100g in 4h and 25.1g/100g in 30 min, which agreed with the yields obtained experimentally for the same time (21.7 and 25.3g/100g, respectively).

Modeling the kinetics of calcium hydroxide catalyzed methanolysis of sunflower oil.

The kinetics of Ca(OH)(2)-catalyzed methanolysis of sunflower oil was studied at a moderate temperature (60 degrees C), a methanol-to-oil molar ratio (6:1) and different catalyst amounts (from 1% to 10% based on oil weight). The methanolysis process was shown to involve the initial triglyceride (TG) mass transfer controlled region, followed by the chemical reaction controlled region in the latter period. The TG mass transfer limitation was caused by the low available active specific catalyst surface due to the high adsorbed methanol concentration. Both the TG mass transfer and chemical reaction rates increased with increasing the catalyst amount.

Kinetics of sunflower oil methanolysis at low temperatures.

The kinetics of the sunflower oil methanolysis process was studied at lower temperatures (10-30 degrees C). The sigmoidal kinetics of the process was explained by the mass transfer controlled region in the initial heterogenous regime, followed by the chemical reaction controlled region in the pseudo-homogenous regime. A simple kinetic model, which did not require complex computation of the kinetic constants, was used for simulation of the TG conversion and the FAME formation in the latter regime: the fast irreversible second-order reaction was followed by the slow reversible second-order reaction close to the completion of the methanolysis reaction. The mass transfer was related to the drop size of the dispersed (methanol) phase, which reduced rapidly with the progress of the methanolysis reaction. This was attributed to the formation of the emulsifying agents stabilizing the emulsion of methanol drops into the oil.

The effect of agitation intensity on alkali-catalyzed methanolysis of sunflower oil.

The sunflower oil methanolysis was studied in a stirred reactor at different agitation speeds. The measurements of drop size, drop size distribution and the conversion degree demonstrate the effects of the agitation speed in both non-reaction (methanol/sunflower oil) and reaction (methanol/KOH/sunflower oil) systems. Drop size distributions were found to become narrower and shift to smaller sizes with increasing agitation speed as well as with the progress of the methanolysis reaction at a constant agitation speed. During the methanolysis reaction, the Sauter-mean drop diameter stays constant in the initial slow reaction region, rapidly decreases during the fast reaction period and finally reaches the equilibrium level. Due to the fact that the interfacial area increases, one can conclude that the rate of reaction occurring at the interface will also be enhanced progressively. The "autocatalytic" behavior of the methanolysis reaction is explained by this "self-enhancement" of the interfacial area, due to intensive drop breakage process.