Characterization Studies for Derived Biodiesel from the Fluid Catalytic Cracking (FCC) of Waste Cooking Oil through a Fixed Fluidized Bed (FFB)

Biodiesel production through transesterification or catalytic hydrogenation using vegetable oil is a sustainable method, but it has the downsides of by-product generation and a higher cost. Therefore, in this study, waste cooking oil was selected as a raw material, and fluidized catalytic cracking was carried out on the catalyst (LDO-75) through a fixed-fluidized-bed (FFB) reactor. The effects of the reaction temperature, catalyst–oil ratio and weight hourly space velocity (WHSV) on the yield of pyrolysis gas, gasoline, diesel and heavy oil fractions were studied. The composition of the pyrolysis gas was determined by gas chromatography (GC), the composition of the gasoline fraction was analyzed by gas chromatography-mass spectrometry (GC-MS), and the characteristics of the diesel and heavy oil fractions were determined by nuclear magnetic resonance (NMR). The results show that light olefins are the main products of pyrolysis gases, and the liquid products are mainly composed of aromatic compounds. In addition, the catalytic cracking process of waste cooking oil fluid is proposed, indicating that the process of the catalytic cracking of waste cooking oil fluid includes deoxygenation, oligoaromatization and hydrodeoxygenation. The results of this study will provide a basis for the high value-added utilization of waste cooking oil.