Bio-fuel production from the catalytic pyrolysis of soybean oil over Me-Al-MCM-41 (Me = La, Ni or Fe) mesoporous materials

In order to obtain a fuel with properties similar to fossil fuel, the catalytic pyrolysis of soybean oil was accomplished over Me-Al-MCM-41 (Me = La, Ni or Fe) mesoporous catalysts. The catalysts were synthesized by hydrothermal method and characterized by X-ray diffraction (XRD). Pyrolysis experiments were performed in a tubular reactor at the constant conditions of temperature 450 °C, weight hourly space velocity (WHSV) 6 h−1 and reaction time 4 h in the absence and presence of the above catalysts. The catalytic activity of the catalysts was studied on the base of the yields and composition of the pyrolysis products. All the pyrolysis products were distilled and classified into three categories according to the distillation temperature (DT) of fossil fuel. (a) Green gasoline (DT ≤ 50 °C); (b) Green diesel (50 °C < DT < 150 °C); and (c) Tar (DT ≥ 150 °C) under vacuum of 100 Pa. The liquid products were examined by Gas chromatography–Mass spectrometry (GC–MS) and elemental analysis, and the tar component was analyzed by the Fourier transform infrared (FTIR). Among the catalysts, the catalyst Ni-Al-MCM-41 showed the best activity which yielded 57.9 wt% bio-fuel, with 9.1 wt% and 48.8 wt% selectivity toward green gasoline and green diesel respectively. Some fuel properties of the diesel fraction were also tested according to the national standard methods in China (GB) and compared with the fuel specification in China. The results showed the bio-fuel obtained from the pyrolysis experiment under Ni-Al-MCM-41 has a good prospect to serve as an alternative for the traditional fossil fuel.