20 research outputs found
Sol-gel Process for the Manufacturing of Translucent Lead Zirconate Titanate Gel-monolith
Translucent Lead Zirconate Titanate (PZT) gel-monolith was prepared by partially hydrolyzing metal alkoxides solution which modified with acetylacetone(acacH). Metal alkoxides, lead di-i-propoxide, zirconium tetra-nbutoxide and titanium tetra-i-propoxide were used as starting materials. In Infrared spectra for the translucent monolithic gel after aging at room temperature for several days or drying at 90°C for 18h, the most significant feature is the presence of band at around 1554 cm-1 which can be assigned to the v (C-O) and v (C-C) vibrati-ons of acetylacetanate group coordinated to the metal cations Ti and Zr. The diffraction peaks of PbO were found after heating at 300°C for 2h. After heating at 450 °C for 2 h, diffraction peaks of pyrochlore Pb2 Ti206 and perovskite PZT phase were observed. The diffraction peaks of PbO and pyrochlore phase disappeared after heating at 600°C, and tetragonal perovskite phase was stable up to 1000 °C. The diffraction peaks of perovskite phase were also found after heating at 430 ° for 24 h. The density of the compacted pulverizedgel after heating at 1000°C for 30 min. was 6.9 g/cm3 , about 86% of the theoretical value
Crystallization Behavior And Micromorphology Of Sol-gel Derived Mesoporous Nano-particles Titania
CRYSTALLIZATION BEHAVIOR AND MICROMORPHOLOGY OF SOL-GEL DERIVED MESOPOROUS NANO-PARTICLES TITANIA. In this work, effects of drying methods on the micro-morphology ofinesoporpous TiO2 prepared by the sol-gel method has been studied using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and N2 gas adsorption. Mesoporous TiO2 consists of anatase nano-particles, about 5nm in diameter, have been obtained by hydrolysis of titanium alkoxide in a methanol solution and supercritical extraction in CO2 at 60°C and 22Mpa. XRD peaks ofrutile have been found after annealing at 600°C. The particle sizes of anatase and rutile are about 13 and 25nm in diameter, respectively. The surface morphology of Ti02 nano-particles has been discussed with the surface fractal dimensions estimated from the N2 gas adsorption isotherms
Carbonization of Palm Oil Empty Fruit Bunch (EFB) in Hydrothermal Processes to Produce Biochar
Empty fruit bunch (EFB) of palm oil is a waste from the palm oil industries which in a large amount, those waste is not properly utilized yet. EFB is a lignocelluloses waste as a polymer with big molecule such as cellulose, lignin, and hemicelluloses that can be degraded into smaller molecules in hydrothermal carbonization (HTC) process. The HTC process of EFB will result three fractions such as gas, organic water soluble and biochar as solid residue or bio-char-water-slurry. EFB degradation is influenced by the operation conditions such as temperature, pressure, catalysts, reaction time, stirring and ratio liquid and solid. The HTC process involved many routes of reaction such as liquefaction, hydrolysis, dehydration, decarboxylation, condensation, aromatization, and polymerization. In this experiment 60 ml closed vessel was used as the HTC reactor to degrade of EFB. EFB concentration of 6.44% resulted 62% of conversion. Reaction time of 6 hours resulted 62 % of conversion. Increasing the reaction time and temperature increase the conversion of EFB. Liquid products of organic water soluble has cleared yellow color, after several hours the color become darkness that is further reaction still occurs in that solution. Solid products is biochar as brown coal, that can be easily separated and processed into powder, pellet or briquette form with outstanding storage and transport characteristics. For further economic development, biochar with excellent transport characteristics, the possibility of exporting this commodity to the world's energy market is possible