Aplicação de resíduo da produção de álcool de segunda geração para remoção de contaminantes emergentes

Abstract

The production of second-generation ethanol (2G) acts directly in the field of industrial sustainability, increasing the production cycles of sugarcane. However, this production generates tons of lignocellulosic residues, which are underutilized, being used exclusively as fuel in boilers, for generating steam and electricity. In this sense, this work aims to study new opportunities for the use of these residues, so that there is an improvement and appreciation of the existing process of the production of 2G alcohol, combined with a reduction of the gases generated by these discards. The objective of the present work was to evaluate the efficiency of activated charcoal, produced from the lignocellulosic residue of 2G alcohol production, as an adsorbent agent in the removal of 17-β-estradiol hormones. Thus, pyrolysis was carried out, evaluating the influence of the variables: pyrolysis temperature (500 and 700 ºC) and heating rate (5 and 15 ºC/min), followed by the physical-chemical activation of the produced biochar. Subsequently, the characterization of biochar and activated carbon was performed by Energy Dispersive X-Ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). In addition to kinetic studies (pseudo-first and pseudo-second order) and the adsorption isotherm (Langmuir and Freundlich). Once all the methodology of the work was done, it was possible to obtain the charcoal produced at 500ºC at 5ºC/min with higher yield and the activated carbon produced at 500ºC at 15ºC/min as the most adequate to carry out the characterizations and adsorption tests. In the immediate analysis it was indicated: high content of volatiles, low content of fixed carbon, ash and moisture. The produced biochars presented several functional groups, including the presence of O-H of carboxylic groups that characterize strong adsorption. The kinetic study showed that the adsorption equilibrium was reached around 90 minutes and the pseudo-second order model is the most suitable for the adsorption. As for the isotherms, the adsorption preferentially follows the model described by Langmuir. Thus, with these studies it was possible to conclude that the material studied has an attractive adsorptive potential, due to the physical-chemical characteristics present.