Biodiesel production from waste frying oils and its quality control

The use of biodiesel as fuel from alternative sources has increased considerably over recent years, affording numerous environmental benefits. Biodiesel an alternative fuel for diesel engines is produced from renewable sources such as vegetable oils or animal fats. However, the high costs implicated in marketing biodiesel constitute a major obstacle. To this regard therefore, the use of waste frying oils (WFO) should produce a marked reduction in the cost of biodiesel due to the ready availability of WFO at a relatively low price. In the present study waste frying oils collected from several McDonald's restaurants in Istanbul, were used to produce biodiesel. Biodiesel from WFO was prepared by means of three different transesterification processes: a one-step base-catalyzed, a two-step base-catalyzed and a two-step acid-catalyzed transesterification followed by base transesterification. No detailed previous studies providing information for a two-step acid-catalyzed transesterification followed by a base (CH3ONa) transesterification are present in literature. Each reaction was allowed to take place with and without tetrahydrofuran added as a co-solvent. Following production, three different procedures; washing with distilled water, dry wash with magnesol and using ion-exchange resin were applied to purify biodiesel and the best outcome determined. The biodiesel obtained to verify compliance with the European Standard 14214 (EN 14214), which also corresponds to Turkish Biodiesel Standards. (C) 2010 Elsevier Ltd. All rights reserved.