Estudo da degradação termocatalítica da cana energia utilizando MCM-41 impregnada com Mo e Zn para a obtenção de hidrocarbonetos renováveis

Abstract

The growing demand for fuels that are alternative to fossil fuels, such as ethanol, has resulted in the exacerbated expansion of sugar cane causing invasions in food lands. In order to eliminate this problem and maintain the growing production of ethanol and other fuels, Cane Energy was developed, presenting high resistance to water stress, pests, drought and soils poor in nutrients, its production is three times greater than the production conventional cane. This biomass can be transformed into renewable hydrocarbons by going through a pyrolysis process and obtaining higher quality hydrocarbons in a thermocatalytic pyrolysis. Thus, this work, in an unprecedented way, aims to synthesize the MCM-41 support and impregnate the metals zinc and molybdenum in 2% when in simple metal oxides and 1% of each when in mixed metal oxides and to study the thermal decomposition and kinetics in the absence and presence of Cane Energy catalysts as a preliminary study to the pyrolysis of this biomass. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM/EDS) showing that the support had a hexagonal structure according to the literature and the metals were inserted without destroying the structure. For a better advantage of the biomass, it was acetylated and analyzed by techniques of elementary analysis (CHN), Fourier transform infrared spectroscopy (FTIR) and thermal analysis (TGA/DTG) in which the modification of the groups –OH by acetyl groups. The thermogravimetric study and the kinetic study were carried out for biomass with and without catalyst using the kinetic models Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS). Based on the R² values, it was noted that the KAS model was more suitable for the study of the present work. From the results of Ea, these indicated that the catalysts MCM-41, MoO3/MCM-41 and ZnOMoO3/MCM-41 decreased the Ea of the biomass thermal decomposition process, in values of 159,69 kJ/mol; 142,33 kJ/mol e 99,15 kJ/mol, respectively.