Producing biodiesel from yellow greases with high free fatty acids

Abstract

Biodiesel is a diesel replacement fuel that is manufactured from vegetable oils recycled cooking greases and oils or animal fats. Biodiesel offers many advantages because it is renewable, nontoxic, biodegradable, and suitable for sensitive environments. It can also be used in most diesel equipments with no or only minor modifications. These yellow greases contain great quantities of free fatty acids which form soaps in the presence of alkaline catalyst. Pretreatments of the raw material with acid catalysts are necessary to avoid the soap formation. The transesterification of yellow greases is supplemented in the presence of an alkaline catalyst. The greatest production of biodiesel corresponds to molar flows of 4.985 kmol.hr-1 of methyl oleate, and 4.658 kmol.hr-1 of methyl butyrate.Biodizel je ekolosko gorivo dobijeno preradom biljnih i zivotinjskih masti recikliranih za kuhinjsku upotrebu (zute masnoce). Ove zute masnoce sadrze velike kolicine slobodnih masnih kiselina koje, u prisustvu alkalnih katalizatora, formiraju sapune. Da bi se formiranje sapuna izbeglo neophodan je pred-postupak tretiranja sirovog materijala kiselim katalizatorima. Reakcija transesterifikacije je kompletna u prisustvu alkalnih katalizatora. Najveca proizvodnja biodizela odgovara molarnom protoku od 4.985 kmol.hr-1 metil oleata i 4.658 kmol.hr-1 metil butirata.