Co/Ru/SBA-15 CATALYSTS SYNTHESIZED WITH RICE HUSK ASHES AS SILICA SOURCE APPLIED IN THE FISCHER-TROPSCH SYNTHESIS

Abstract

Synthesis processes using simple compounds become attractive as they offer alternative routes for fuel production. Cobalt-based catalysts have wide applicability in the Fischer Tropsch process. This work aims to evaluate the catalyst Co/Ru/SBA-15 in the Fischer Tropsch synthesis. The catalyst was prepared with the molecular sieve SBA-15 synthesized using the hydrothermal method with rice husk ashes, treated by heat and chemical processes, as silica source; and incorporating, simultaneously, metals by wet impregnation of molar ratio 100Co/5Ru/139SiO2. The catalyst was submitted to heat treatment under nitrogen and synthetic air flow. The Fischer Tropsch synthesis was carried out in a slurry bed reactor operating at 240oC, 10 atm, and H2:CO molar ratio raging between 1 and 2. The SBA-15 and the catalyst were characterized by X-ray diffraction- XRD, X-ray energy dispersion- EDX, and nitrogen adsorption. The SBA-15 was characterized using scanning electron microscopy- SEM, and the catalyst was characterized by temperature programmed reduction - TPR and transmission electron microscopy - TEM. SBA-15 showed typical morphology traces of mesoporous materials with a small specific area of 627 m2/g. The catalyst presented the pre-defined composition, maintaining the structure, but with area reduction after impregnation (339 m2/g). The ranges of temperature reduction typical of iron oxides phases were found using RTP results. The catalyst showed high conversion to liquid hydrocarbons C5+ (88.20%) in the molar ratio H2/CO of 1:1.