Enzyme-catalyzed production of biodiesel by ultrasound-assisted ethanolysis of soybean oil in solvent-free system.

This work reports the transesterification of soybean oil with ethanol using a commercial immobilized lipase, Novozym 435, under the influence of ultrasound irradiation, in a solvent-free s. The experiments were performed in an ultrasonic water bath, following a sequence of experimental designs to evaluate the effects of temperature, enzyme and water concentrations, oil to ethanol molar ratio and output irradiation power on the reaction yield. Besides, a kinetic study varying the substrates molar ratio and enzyme concentration was also carried out.

A review on lipase-catalyzed reactions in ultrasound-assisted systems.

The named "green chemistry" has been receiving increasing prominence due to its environmentally friendly characteristics. The use of enzymes as catalysts in processes of synthesis to replace the traditional use of chemical catalysts present as main advantage the fact of following the principles of the green chemistry. However, processes of enzymatic nature generally provide lower yields when compared to the conventional chemical processes.

Continuous lipase-catalyzed esterification of soybean fatty acids under ultrasound irradiation.

This work investigates the continuous production of alkyl esters from soybean fatty acid (FA) charges using immobilized Novozym 435 as catalyst. The experiments were performed in a packed-bed bioreactor evaluating the effects of FA charge to alcohol (methanol and ethanol) molar ratio, from 1:1 to 1:6, substrate flow rate in the range of 0.5-2.

Ultrasound-assisted lipase-catalyzed transesterification of soybean oil in organic solvent system.

This work reports the transesterification of soybean oil with ethanol using two commercial immobilized lipases under the influence of ultrasound irradiation. The experiments were performed in an ultrasonic water bath, following a sequence of experimental designs to assess the effects of temperature, enzyme and water concentrations, oil to ethanol molar ratio and output irradiation power on the reaction yield. Results show that ultrasound-assisted lipase-catalyzed transesterification of soybean oil with ethanol might be a potential alternative route to conventional alkali-catalyzed method, as high reaction yields (~90 wt.