Conversão fotocatalítica de metano em metanol: desenvolvimento do equipamento e experimentos

Abstract

Due to increasing awareness regarding the environment, some gases such as methane have been extensively studied in order to have their usage optimized, aiming to reduce environmental impacts and the discovery of more noble applications. Given this context, photocatalysis emerges as an alternative for the conversion of methane into products with higher added value. The method of obtaining methanol from methane has several advantages, since methanol not only has a methane-like amount of energy, but also is easily transported and stored. This work searches for a viable alternative for the photocatalytic production of methanol from methane vapor reform, the development of a new system, as well as the evaluation of its operation and conversion efficiency. The system consists of a humidification column, an annular photocatalytic reactor, stainless steel screens coated with titanium dioxide, zinc oxide or tungsten trioxide and a condenser. The photocatalysts, deposited on the screens through the method that had been adapted from Merajin et al (2018), were activated with the aid of UV-A and UV-C emission lamps, arranged inside the reactor at different times. Oxides and supports were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and diffuse reflectance spectroscopy (ERD) techniques, for evaluation of the homogeneity of the coatings and to ensure that the photocatalysts meet the process requirements. The photocatalytic tests were conducted at ambient pressure and temperature. As a result of the depositions, through the SEM images, it is possible to observe that the photocatalysts presented an excellent distribution, confirming the adequacy of the technique used in relation to the purposes of the study. Although the system was operational, the products of the process, analyzed by gas and liquid chromatography, did not show any evidence of conversion under the experimental conditions.