Pembuatan biodiesel dari minyak jarak (castor oil) menggunakan fotokatalis komposit K2O-Tio2/Zeolit sebagai energi alternatif ramah lingkungan

Utilizing biodiesel as an alternative fuel has constraints such as the using of homogeneous catalysts. Biodiesel production using homogeneous catalyst needs a lot of solvent and catalyst. To reduce solvent and catalysts in the biodiesel production were needed a heterogeneous catalyst. This research was aimed to utilize K2O-TiO2/zeolite composite as a heterogeneous alkaline photocatalyst. Natural zeolites were activated by soaked in HCl 6 M, and then soaked KOH 20% (v/v). Physical activation was carried out by calcination at 450 °C for 4 hours. Synthesis of K2O-TiO2/zeolite composite was completed by hydrothermal method. Activity of catalyst was tested by varying the composition of the K2O/zeolite composite against castor oil with reflux at 60 °C. The activity was compared with composite photocatalytic activity of TiO2-K2O/zeolite at room temperature. The composite material was analyzed by XRD and the transesterification was monitored by FTIR and GCMS. Biodiesel product was evaluated by acid number, density, and water content. The results of catalyst activity of K2O/zeolite and K2O-TiO2/zeolite showed that utilizing K2O-TiO2/zeolite composite as a photocatalyst in the biodiesel manufacture from castor oil was not effective. It was indicated with the presence of free fatty acids. GCMS analysis showed that castor oil samples have not been converted. FTIR spectra showed no changes in the vibrations of the functional group of castor oil and biodiesel product