MÉTODOS ALTERNATIVOS PARA LA OBTENCIÓN DE BIODIESEL, MICROONDAS Y ULTRASONIDO

Abstract

Transesterification of vegetable oil with short-chain alcohols, in the presence of basic catalysts with low-frequency ultrasound (28 and 40 kHz) reduces reaction time. The amount of catalyst required is 2 or 3 times lower and relationship oil alcohol is low (1:6). ^[15]

The application of ultrasound enhances mass transfer and speed of chemical reactions, but some theoretical aspects and engineering are not well understood. ^[1]

The use of the microwave (MW) in the chemical has accelerated reactions through a warming faster and more efficient, savings time, an increase productivity, low pollution, replicable procedures. But the microwave does not interact in the same way with all the materials and there may be a risk of explosion by overheating. ^[4]

Microwaves are non-ionizing electromagnetic radiation. It does not cause changes in the molecular structure but produce molecular movement, migration of ions and rotation of dipoles. It generates friction by molecular collisions which make the material get hot. ^[3]

Processing materials with microwave is complex and involve a large number of variables. Therefore it requires a high degree of technical knowledge to determine how, when and where technology is used more effectively and when it can not be use. ^[5]

In this paper we want to describe: the most relevant aspects affecting these technologies, their advantages and disadvantages in obtaining biodiesel and some experimental results in the application of microwave to alkylesteres synthesis of crude palm oil. It is used as additives for improve the properties of flow at low temperatures.