The production of renewable aviation fuel from waste cooking oil. Part I: Bio-alkane conversion through hydro-processing of oil

Renewable aviation fuel produced from hydro-processing has been a commercially available technique currently. Studies conducted recently were toward finding an appropriate catalysts to produce the jet fuel range products with high normal alkanes and low aromatics. This study focused on hydro-processing of waste cooking oil (WCO) into straight alkanes, which can serve as the blendstock for aviation fuel after further cracking and isomerizing, over two different catalysts, pre-sulfurized NiMo/γ-Al2O3 and Pd/C, under various experimental conditions such as reaction temperature, pressure, liquid hourly space velocity (LHSV) and H2-to-oil ratio. The resulting liquid and gas products from the two catalysts were analyzed through GC-MS/FID and GC-TCD for judging the performances of hydro-deoxygenation (HDO) as well as decarboxylation (DCO2)/decarbonylation (DCO). The fresh and spent catalysts were examined through XRD, FTIR, TGA and SEM to characterize the catalysts before and after hydro-processing. The performance of Pd/C, based on the concentrations of produced C15∼C18 normal alkanes, was higher than NiMo/γ-Al2O3 with low reaction temperature, low hydrogen pressure, low LHSV, low H2-to-oil ratio and short time-on-stream.