Conversion of used vegetable oils to liquid fuels and chemicals over HZSM-5, sulfated zirconia and hybrid catalysts

Thailand’s food manufacturing uses about 47 Million liters per year of vegetable oil. Used vegetable oil is classified as waste, but has potential for conversion into liquid fuel. This research studied the catalytic conversion of used vegetable oil to liquid fuel, where investigation was performed in a batch microreactor over a temperature range of 380–430 °C, initial pressure of hydrogen gas over 10–20 bars, and reaction time of 45–90 minutes. Catalysts such as HZSM-5, Sulfated Zirconia and hybrid of HZSM-5 with Sulfated Zirconia were used to determine the conversion and yield of gasoline fraction. The major products obtained were liquid products, hydrocarbon gases and small amounts of solids. Liquid products were analyzed by simulated distillation gas chromatograph and the product distribution was obtained. Hybrid catalyst HZSM-5 with Sulfated Zirconia showed the highest yield of gasoline with a 26.57 wt% at a temperature of 430 °C, initial hydrogen pressure at 10 bars, and reaction time of 90 minutes in the ratio of hybrid HZSM-5 with Sulfated Zirconia at 0.3: 0.7.