Abstract
Used frying fats and oils with highly variable and uncontrolled quality are used for the production of biodiesel . The objective of this study was to define the analytical methods useful to obtaining information on the quality of the used frying oils as raw material for biodiesels as well as for the characterization of the biodiesels obtained from them. Twentyfour used frying oils from restaurants and domestic fryers were analyzed before and after transesterification to fatty acid methyl esters (FAME). From a detailed analysis of the samples by means of a combination of adsorption and size exclusion chromatography, the quantitative importance of polymeric compounds was deduced both from the direct analysis of the oils and from their FAME. Excellent linear correlation between polar compounds and polar FAME (R=0.9768) was found. The possibilities of interferences from polar fatty acid in the standard method to determine the ester content are defined. Finally, determination of non-polar FAME by silica column is proposed as a good alternative to the gas chromatography method.
Highlights
The base-catalyzed transesterification method is normally applied for biodiesel production
The recent concerns over sustainability, environmental issues, and raw material costs have made the use of used frying oils very attractive to the industry
There have been a significant number of studies over the last decade with the aim of establishing the optimum conditions for biodiesel production using frying oils as raw material (Costa Neto et al, 2000; González Gómez et al, 2002; Leung, 2001; Al-Widyan et al, 2002; Supple et al, 2002; Tashtoush et al, 2004; Tomasevic and SilerMarinkovic, 2003; Zhang et al, 2003 a, b; Felizardo et al, 2006; Leung and Guo, 2006) or evaluating their performance as fuels (Mittelbach and Tritthart,1988; Al-Widyan and Al-Shyoukh, 2002; Zaher, 2003; Dorado et al.,2003; Ulusoy el al., 2004)
Summary
The base-catalyzed transesterification method is normally applied for biodiesel production. The recent concerns over sustainability, environmental issues, and raw material costs have made the use of used frying oils very attractive to the industry In this respect, there have been a significant number of studies over the last decade with the aim of establishing the optimum conditions for biodiesel production using frying oils as raw material (Costa Neto et al, 2000; González Gómez et al, 2002; Leung, 2001; Al-Widyan et al, 2002; Supple et al, 2002; Tashtoush et al, 2004; Tomasevic and SilerMarinkovic, 2003; Zhang et al, 2003 a, b; Felizardo et al, 2006; Leung and Guo, 2006) or evaluating their performance as fuels (Mittelbach and Tritthart,1988; Al-Widyan and Al-Shyoukh, 2002; Zaher, 2003; Dorado et al.,2003; Ulusoy el al., 2004). Some of them are linked to the process itself, such as temperature, length of heating, continuous or discontinuous heating, turnover period, etc.; others to the food subjected to frying, i.e. lipid composition, main and minor constituents, etc.; or else to the fat or oil used e.g., unsaturation degree, initial quality and additives (Varela, 1985; Rodrigues Machado et al, 2007)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
