Síntese da peneira molecular SBA-15 por métodos de aquecimento distintos e desenvolvimento de catalisadores (Co/SBA-15 e Ru/Co/SBA-15) destinados à reação de Fischer-Tropsch.

Abstract

The introduction of ruthenium as a promoter emerges as a promising alternative for reduce cobalt oxide particles much more easily, increase the cobalt dispersion and inhibit catalyst deactivation. Therefore, this The objective of this work is to prepare the molecular sieve SBA-15 using different heating methods and to evaluate in the Fischer-Tropsch reaction the 20% Co / SBA-15 (conventional), 20% Co / SBA-15 (microwave) catalysts and 0.5% Ru20% Co / SBA-15 (conventional). The catalysts were prepared by wet impregnation using SBA-15 molecular sieves as support. At SBA-15 molecular sieve, conventional and microwave methods, was impregnated with cobalt through the aqueous cobalt nitrate. Following was incorporated the ruthenium promoter using chloride solution. The samples were characterized by DRX, EDX, ATD, RTP, SEM and physical adsorption of N2. The reaction of Fischer-Tropsch was conducted at 240 ° C, 20 bar pressure using a molar H2 / CO = 1 in a mud bed reactor during a reaction time of 8 h. THE obtaining the mesoporous molecular sieve, SBA-15 by the heating methods conventional and microwave energy can be confirmed by diffractograms X-ray, highlighting the SBA-15 obtained with short crystallization times by the microwave energy heating method. The surface areas Specific pores decrease and pore volume varies due to pore blockage by the cobalt and the ruthenium promoter, but the structure of the SBA-15 molecular sieve is not amended. The RTP profiles of the Co / SBA-15 and Ru / Co / SBA-15 series catalysts allowed to verify the presence of distinct peaks that can be caused by the cobalt dispersion. The results obtained from Fischer-Tropsch synthesis catalysts showed high selectivity to high (C5 +) hydrocarbons. added value, as well as the co-impregnation of the ruthenium promoter. catalyst Co / SBA-15 (conventional method) favored the increase of selectivity for C5 + hydrocarbons. The catalysts under study presented high selectivity at C5 + higher than selectivity of commercial catalysts supported on silica reported by the literature.