Carbon monoxide adsorption on conventional activated carbon and impregnated with 5% niobium

ABSTRACT

Air pollution and global warming are problems that have been worsening over the decades mainly due to human activities. The combustion process in industries and motor vehicles releases considerable amounts of gaseous pollutants into the atmosphere. In this context, the present work aims to evaluate the efficiency of conventional activated carbon and impregnated with 5% niobium in the adsorption of carbon monoxide. The adsorbents were characterized by Fourier transform infrared spectroscopy - FTIR, scanning electron microscopy - SEM, N₂ adsorption / desorption and X-ray diffraction - XRD. The dynamic adsorption studies were carried out with an adsorbent mass equal to 3.5 g in a fixed bed with a flow rate of 500 mL min^-1 of a mixture of 500 ppm CO in N₂ with a gas analysis system with an electrochemical cell at room temperature. From the results of the characterizations, it was possible to observe that the presence of niobium in the adsorbent structure led to a decrease in the surface area and pore volume of the activated carbon, but with a certain increase in the pore dimensions observed by SEM. Regarding the adsorption tests, the result of better efficiency occurred with the adsorbent coal / 5% niobium, the presence of niobium in the adsorbent material obtained an increase in oxygen, favoring the adsorption process. The experimental data of fixed bed adsorption for both adsorbents obeyed a Boltzmann sigmoidal nonlinear distribution model. The results of the CO adsorption tests can be said that the performance of the adsorbents conventional activated carbon and activated carbon with impregnated niobium are effective in the adsorption of CO, being a promising process in minimizing carbon monoxide emissions.

Keywords
adsorption; carbon monoxide; physical and chemical characterization; activated carbon; niobium