Biodiesel production from waste frying oils in the presence of zeolite synthesized from steel furnace slag

Furnace slag is a by-product of the steel industry containing high amounts of silica. This inexpensive material existsin large quantities and can be used for the synthesis of zeolite. In the present study, a zeolite was synthesised using the slag by hydrothermal method, and it was used in biodiesel production from waste oil. Analysis of the physical and chemical properties of synthesised zeolitewas performed using XRF, TGA, BET, FE-SEM,XRD and EDAX.In catalysing biodiesel production, effective parameters on biodiesel production including reaction time, the molar ratio of methanol to oil, and the catalyst dosehave been investigated.The produced biodiesel was analysed by gas chromatography (GC) and its characteristics were compared with the ASTM D-6751 standard. In the optimised conditions including the molar ratio of methanol to oil 12, the reaction time of 4 h and, catalyst dose of 3 Wt. %, about 96% of biodiesel production was achieved.The reusability of the catalyst was also investigated and it was found that the catalyst can be recovered and reused for several times. Accordingly, it can be concluded that the synthesised zeolite in the present study can be a useful material for biodiesel production.