Conference article

Biodiesel cannot economically compete with petroleum-based diesel fuel because of its high cost problem. This problem may be solved with the use of low cost feedstocks in biodiesel production. Waste frying oils are one of the low cost feedstocks. However; the feedstocks’ properties to be processed must be controlled in detail prior to transesterification reaction; since the physical and chemical properties of the feedstock significantly influence biodiesel production reaction as well as fuel properties. Frying oils which are used in various facilities in different conditions (such as frying temperature; time; and kind of food) have significantly different physico-chemical properties. Therefore; in this study; 30 different waste frying oil samples (14 from fish restaurants; 5 from fast-foods; 5 from hospitals; 4 from pastry shops; and 2 from restaurants) were collected and their density; viscosity; total polar material; water content; acid value; iodine value; peroxide value; and heating content were determined and compared to each others. The correlations between the total polar material content (which has to be legally determined to monitor frying oil’s degradation level) and density; viscosity; acid value and water content were remarkable. The usage of peroxide value to decide the quality of an oil was misleading.

Biodiesel; Low cost feedstock; Waste frying oil; Characterization