Biodiesel by Transesterification of Rapeseed Oil Using Ultrasound: A Kinetic Study of Base-Catalysed Reactions

Abstract

The objective of this work was to study the acceleration that ultrasound causes in the rate of biodiesel transesterification reactions. The effect of different operating variables, such as ultrasound power, catalyst (KOH) concentration and methanol:oil molar ratio, was studied. The evolution of the process was followed by gas chromatography, determining the concentration of methyl esters at different reaction times. The biodiesel was characterized by its density, viscosity, saponification and iodine values, acidity index, water content, flash and combustion points, cetane index and cold filter plugging point (CFPP), according to EN 14214 standard. High methyl ester yield and fast reaction rates were obtained in short reaction times. Ultrasound power and catalyst concentration had a positive effect on the yield and the reaction rate. The methanol:oil molar ratio also increased the yield of the reaction, but negatively influenced the process rate. The reaction followed a pseudo-first order kinetic model and the rate constants at several temperatures were determined. The activation energy was also determined using the Arrhenius equation. The main conclusion of this work is that the use of ultrasound irradiation did not require any additional heating, which could represent an energy savings for biodiesel manufacture.

Bio-Energy Recovery from Canola Oil and Wastewater as Co-Substrates

“…Approximately 23 kg of canola seed used to extract 10 l of canola oil, while, the remainder from the extraction process (canola meal) can be used as animal feed. Canola oil now serves as the essential feedstock in Europe for biodiesel production Encinar et al, (2018). The canola oil is widely used as a source for biodiesel production in an effort to reduce the cost of production, whereas it is less expensive than other vegetable oils and therefore has become a favorable alternative.…”

Optimization of Cerbera manghas Biodiesel Production Using Artificial Neural Networks Integrated with Ant Colony Optimization

“…The renewable energy that is easiest to handle is biofuel, which has no storage problem and is easily transported. One alternative source of energy is biodiesel, which is an alternative fuel that can be produced from a variety of feedstock, including edible and non-edible plant-based oils, animal fats, and even waste cooking oils [13][14][15]. The possibilities of biodiesels are endless-the physicochemical properties of these fuels can be tweaked by making judicious selection on the types of feedstock and the types of processes used for biodiesel production (e.g., degumming, esterification, neutralization, transesterification, and purification), by blending biodiesels with other types of biodiesels or fuels such as bioethanol and diesel, or even by optimizing the process conditions of biodiesel production.…”

Biofuel and Bioenergy Technology

“…This Special Issue of Energies on the subject of "Biofuel and Bioenergy Technology" contains the successful invited submissions . A total of twenty-seven technical papers which cover diversified biofuel and bioenergy technology related researches have shown critical results and contributed significant findings in biomass processing [1,2], bio-oil and biodiesel [3][4][5][6][7][8][9][10][11], syngas [12][13][14], biogas/methane [15][16][17][18][19], bioethanol and alcohol-based fuels [20][21][22], solid fuel [23][24][25] and also microbial fuel cell [13,26,27] developments.…”

“…These findings suggest that simple blending could improve the properties of biodiesel or bio-oil tremendously, which is worthy of further investigation. Aside from using bio-oil as a precursor for biodiesel [3], biodiesel could be directly synthesized using other oil materials such as Australian native stone fruit oil [6], rapeseed oil [7], Rhodotorula glutinis [8] and soursop seed oil [9] via transesterification techniques. Transesterification of Australian native stone biodiesel showed a high yield of 95.8% with the response surface methodology optimization and its quality fulfilled the ASTM D6751 and EN14214 requirements [6].…”

“…The biodiesel produced met both EN14214 and D6751 standards. Encinar et al [7] performed rapeseed transesterification with KOH catalyst as well as with the aid of ultrasound whereby the kinetic behavior obeyed a pseudo-first order trend. Liquid lipase-based esterification was attempted and optimized using RSM to enhance the usage of water removal agent in the system [11].…”