Improvement of biodiesel production based on the application of ultrasound: Monitoring of the procedure by FTIR spectroscopy

Abstract

A novel application of ultrasounds is presented for the improvement of the efficiency of the production of FAME (or biodiesel) from materials not used so far for this purpose, such as seed cakes. The novelty of this work is the introduction of in situ derivatization assisted by ultrasounds (ultrasonically assisted ex-traction transesterification) for biodiesel production. Thus, the TG contained in solid material are extracted and immediately transesterified in a methanolic solution of 1 M NaOH in an ultrasonic field. The total yield of FAME from seeds that contain TC is greatly increased in most instances. In the seeds used in this work, yields were increased from 46 to 85.5 % for cotton, 67.2 to 93 % for sunflower, and 43.2 to 83.5 % for sesame. An FTIR methodology was developed to determine the percentage of FAME in the n-hexane layer of the reaction and thus, to monitor the reaction process. Overall advantages of the proposed methodology include the elimination of saponification, low reaction time, milder reaction conditions, and higher FAME yields. Copyright © 2006 by AOCS Press.