Heterogeneous catalysts are commonly used in biodiesel production. The CaO heterogeneous catalyst can be prepared by calcination process from one source of CaCO3 prepared from crab shell. The preparation of heterogeneous catalyst was successfully carried out by activation with KOH and doped with ?-Al2O3. The purpose of this study is to determine the characteristics of the CaO/?-Al2O3heterogeneous catalyst and the performance of the catalyst for converting oleic acid into biodiesel. The results of this study that the best characteristics of catalyst were shown by CaO/?-Al2O3 100:7, which has a surface basicity was 20,9532 mmol g-1 with active sites 12,6181x1019atom g-1, and specific surface area of ??42.0979 m2/g. The results of using CaO /?-Al2O3 catalyst for converting oleic acid into biodiesel with the optimum concentration was 5%, the optimum oil/methanol molar ratio of 1:9, and the optimum reaction time of 120 minutes for converting oleic acid into biodiesel with the yield of 89.80%. The characteristics of the final biodiesel obtained had met the Indonesian National Standard (SNI 7182-2015) with density (at 40oC), kinematic viscosity (at 40oC), water content, iodine value were 863 kg/m3; 4.8 cSt; 0.039%, and 35.3562 g I2/100g, respectively. Keywords: CaO/?-Al2O3, oleic acid,biodiesel, heterogeneous catalyst.

Ilmenite is a natural material in the form of sand which contains heavy metal minerals that are very abundant in Lampung province. This research aims to determine the content of TiO2 from Lampungs iron sand by leaching method with temperature variation. The iron sand are mixed with sodium hydrogen carbonate (NaHCO3), then heated at 700 • C for an hour. This research uses 5 samples with leaching temperature variation of 70, 80, 90, 100, and 110 • C for 2 hours. The acid leaching process uses HCl 12 M with a ratio of iron sand and HCl of 1:4, while the water leaching process uses 50 ml of distilled water. Furthermore, the samples are characterized using XRD and XRF to determine TiO2 content in the iron sand. The result shows that the highest amount of TiO2 is obtained in the sample with the leaching temperature of 110 • C for 2 hours, which is approximately 61%.

This study aims to make a thin layer of TiO2 based on ilmenite stored in iron sand of Lampung Province, Indonesia. The TiO2 powder, which was used to make the thin layer, was obtained from the extraction of iron sand using the leaching method with a purity of 60,7%. The preparation of TiO2 thin layers was carried out by the Chemical Bath Deposition (CBD) method with immersion time variations of 2, 3, 4, and 5 hours for samples A, B, C, and D respectively. Afterward, the samples were calcined at 500°C for 4 hours. The characterizations involved X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-Ray Fluorescence (XRF), and four-point probe to measure the resistivity of the film. The XRD results in samples A (immersion time 2 hours) and D (immersion time 5 hours) show that the amorphous phase still dominates even though the diffraction peaks indicate that the presence of crystals has started to grow at several angles of scattering. The identification results of the phase presence show that the thin layer of TiO2 at sample D is the brookite phase. The results of characterization using SEM show that the surface of the TiO2 thin layer forms a porous structure. The average thickness of the thin film at sample B based on SEM analysis is 1.9 μm. The electrical resistivity increased with an increasing immersion time.