Síntese e caracterização do catalisador de Ni/AL 203 para a produção de hidrogênio por reforma a vapor do etanol

Abstract

The world energy matrix primarily presents the generation of electricity through the burning of fossil fuels such as coal, oil and natural gas. However, the gaseous compounds released in this burning are harmful to the health of the population and the environment as it results in the emission of atmospheric pollutants such as carbon monoxide, nitrogen oxides, and sulfur dioxide, the latter with the possibility of causing acid rain. Aiming to produce cleaner and more environmental friendly energy, hydrogen has been recognized as the most viable source of electricity for the future. One way to produce hydrogen is through the catalytic reaction of ethanol steam reforming. The use of the catalyst accelerates the reaction, increasing the process productivity. The objective of this work is to synthesize a heterogeneous metallic catalyst, specifically, a Ni-based catalyst supported on alumina, with different metallic contents, 10, 20, and 30 %. For this, a wet impregnation method was used. The synthesized catalysts were physically and chemically characterized through nitrogen physisorption (BET) and X Ray Diffraction (DRX) tests. The catalyst chosen for the characterization and subsequent application in the ethanol steam reforming reactions was the 30Ni/Al2O3, which had a surface area, pore volume, and pore diameter of 34.16 m²/g, 0.087 cm³/g, and 2.5 nm, respectively. The material was classified as mesoporous, according to the classifications presented by IUPAC. Finally, three tests were performed to conduct the ethanol steam reforming reaction with the 30Ni/Al2O3 catalyst, the first with the commercial catalyst, at a temperature of 500 °C, the second at a temperature of 500 °C, and the third at a temperature of 700 °C, with the synthesized catalyst. The gases collected throughout the reactions were subjected to gas chromatography to measure the hydrogen concentration, resulting in 79.69 %, 78.38 %, and 94.03 % for the three tests, respectively. According to the results, it was possible to observe that at a temperature of 700 °C, the production of hydrogen increased. In addition, the synthesized catalyst was more selective when compared to the commercial catalyst, producing a smaller amount of by-products, mainly CH4.