Production And Upgrading Of Biofuels In Aviation Based Source Conditioning

Increased demand in global air transportation fuels and severe aviation carbon tax have caused great attention on exploitation of surrogate fuels such as aviation biofuel, which is of great significance for reducing dependence on fossil fuels and taking a road to sustainable development. The method based on supercritical fluid technology combined with torrefaction pretreatment has been used to convert biomass into bio-oil, which was prepared for biomass-derived aviation fuel. The modern analytical instruments such as chromatography and mass spectrometry (GC-MS), Fourier transform infrared spectrometry (FTIR), Karl Fischer moisture titrator, closed cup flash point tester, and existent gum tester were used for the results analysis.Firstly, the rice stalk (RS) was pretreatment by torrefaction conducted in a fixed-bed reactor. It was observed from FTIR and chemical composition results that the thermal decomposition of hemicellulose was the main reaction that occurred between200℃and280℃with dehydroxylation and decarbonylation reactions. Secondly, the RS was liquefied in ethanol under sub/supercritical conditions in an autoclave. A RS conversion of78.32%and followed55.03%of oil yield were obtained under an suitable condition with a1/10g/mL RS to ethanol ratio at325℃and a residence time of60min. At the same time, the effect of torrefaction temperature (200℃,240℃, and280℃) on the composition and physicochemical properties of bio-oil were also investigated. GC-MS analysis showed that a maximum acid content of3.17%was achieved in RS, whereas the lowest value of0.35%was achieved in TRS at a temperature of200℃. The esters, which were largely produced from the esterification between acids and alcohols, also reached a maximum value of30.6%at200℃. As the torrefaction temperature was increased, the moisture content was slightly decreased from2.23%to1.31%. The heating value was also increased and reached a maximum value of32.53MJ/kg at200℃The biomass-derived aviation fuel was produced from the bio-oil (volume fraction5%) obtained from TRS at200℃mixed with RP-3jet fuel (volume fraction95%). The test results showed that some of the physical and chemical properties were not fit for NO.3jet fuel specification. The biomass-derived aviation fuel was higher in acid value, which was increased from0.005mgKOH/g to0.2703mgKOH/g, higher in existent gum, which was increased from1.7mg/100mL to446.8mg/100mL, and higher in freezing point, which was increased from-50.7℃to-40℃. On the other hand, it was excellent in some performance such as high-flash point, which was increased from42℃to47℃and high-density, which was increased from777.6kg/m3to810.5kg/m3.