Production of biodiesel from oil via electrolysis using KOH/Clinoptilolite as catalyst.

Backgrounds: In recent years, fossil fuels are the main energy supply in both transportation and industry. Their increasing consumption has been causing global warming and acid raining. One of the alternative fuels that is considered today is biodiesel, which is clean and eco-friendly. The main method for biodiesel production is transesterification reaction of triglyceride oil with methanol in the presence of a suitable catalyst.

Method: In this research, biodiesel was produced from oil in the presence of KOH/Clinoptilolite catalyst. The impregnation, hydrothermal, and incipient wetness methods were used for loading KOH on the Clinoptilolite support to produce biodiesel via electrolysis method. The characteristics of the KOH/Clinoptilolite catalyst were examined through scanning electron microscopy (SEM), energy dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analyses. The effects of key parameters including catalyst amount, methanol to oil molar ration, reaction time, reaction temperature, co-solvent type and its proportion, electrolysis voltage, catalyst reusability, and KOH concentration were examined on the biodiesel yield.

Results: The results of elemental analysis confirmed that KOH was well loaded on Clinoptilolite support. The highest yield of biodiesel was obtained 79% in the presence of 10 wt% catalyst, alcohol to oil ratio of 9:1, acetone concentration of 10 wt%, temperature of 60 °C, and voltage of 10 V. The results of GC-MS, FTIR and H-NMR analyses illustrated that biodiesel as a product was produced with good quality.

Conclusion: Based on the obtained results, in all three methods of catalyst synthesis KOH was loaded on Clinoptilolite support but at the end of the transesterification reaction only the catalyst synthesis via incipient wetness method could be reused three times under optimum reaction conditions. The produced biodiesel had high quality, whose physical and chemical properties had good agreement with ASTM, EN 14214, IS 15607 standards. Since the oil is an appropriate feedstock source for biodiesel production, it is suggested to use oil and KOH/Clinoptilolite catalyst to produce biodiesel on industrial scale.