Neutralization or Esterification as Input Improvement Techniques for Biodiesel Production

In this work, two effective ways for reducing the acidity of raw materials aimed to biodiesel production were tested, one being the neutralization and other the esterification of free fatty acids. Residual chicken fat and waste cooking oil were tested, since both are generated in large volumes, however they have not been used as major raw materials in the commercial biodiesel production process due to their quality. The samples were previously characterized with the determination of water content, acid value and peroxide value and reanalyzed at the end of each process. The initial results of characterization showed that samples were high acid and under a advanced oxidation state. After the purification step there was a significant reduction in the values of acidity and peroxide, with emphasis on chicken fat which had a reduction of 96.5 % in acid number after the neutralization step and peroxide number bellow 10 meq/kg. It should be emphasized that, in the case of samples with high acid number, such as chicken fat, comparing the two treatment processes, greater mass yield results were obtained for the esterification process, with 87.66 % while for neutralization the yield was 58.85 %.