Researchers from Malaysia performed an experiment to analyse the efficiency of biodiesel conversion from crude castor oil to castor oil biodiesel. Acid-base catalysed transesterification reaction was carried out under different reaction conditions to obtain high yield of castor biodiesel.
Diesel engine performance and emission tests with different castor biodiesel blends showed that B20 blend of castor biodiesel had same engine power output as other mineral diesel with lower average percentage of change in CO and HC emissions. Thus, B20 blend of castor biodiesel could be a suitable alternative to diesel.
Scientists from Iran performed an experiment to optimize the ultrasound assisted biodiesel synthesis from castor oil using response surface methodology. Parameters such as reaction time, methanol to oil molar ratio, ultrasonic cycle and ultrasonic amplitude were taken into consideration to optimize the biodiesel synthesis process.
Through RSM analysis, it was found that the reaction time has the most significant effect on the reaction yield.
Researchers from Spain conducted an experiment to compare conventional and ultrasound-assisted transesterification for the production of biodiesel from castoroil. The results showed that sonicated transesterification leads to higher castoroil methyl ester yield.
The energy required along each type of transesterification was measured which showed that sonicated transesterification consumes lower amount of energy than conventional one.
Microemulsion technique is employed to reduce the viscosity of vegetable oils, which is used as the source of renewable fuels. A recent study is conducted by Ren zhu et al., on the phase behavior of microemulsion and the solubilization mechanism of water and castor oil, in order to evaluate the solubilization capacity of water and castor oil in diesel under given conditions. The proper concentration of rhamnolipid (RL) was 50 g/L. N-octanol was certified as an ideal cosurfactant with the optimal cosurfactant/surfactant (C/S) mass ratio (w/w) of 0.60. The optimum castor oil/diesel (V/D) volume ratio (v/v) was 0.18. Moreover, fuel properties of water-containing castor oil/diesel (WCD) microemulsion were identified. The thermal and storage stability of WCD microemulsion were also conducted. Compared with castor oil, WCD microemulsion has lower viscosity, which presents similar fuel characteristics as diesel.
Some important properties of biodiesel such as viscosity, melting point, thermal stability, and cetane index can be directly related to the chemical composition of the biomass source used. However, the viscosity of castor oil ethyl ester (COEE) is about four times greater than the biodiesel viscosity specification, and this fact restricts the uses of this biofuel. The main goal of this work is to investigate the physical–chemical properties of COEE in ethanol blends and present an option to decrease the castor oil biodiesel viscosity specification. COEE viscosity is 14.413 mm2/s. The results show an evident decrease in biodiesel viscosity with the addition of ethanol. Samples with 30, 40, and 50 vol % of ethanol present the following viscosities 5.316, 4.044, and 3.136 mm2/s, respectively. These results are in agreement with Brazilian National Agency of Petroleum, Natural gas and Biodiesel (ANP), and European (EN 14214) specifications. Three correlations that describe the decrease in viscosity and density with ethanol concentration, and the variation of viscosity with the density in COEE ethanol blends were obtained. The behavior of COEE ethanol blends with diesel also were analyzed. The increase in solubility of ethanol in commercial diesel was verified because COEE acts as a cosolvent in an ethanol–diesel mixture.