Utilização do Líquido Pirolenhoso como Inibidor de Corrosão para o Aço Carbono 1045 em HCl

Abstract

This study evaluated the use of pyroligneous liquid (LP) obtained from eucalyptus wood as a corrosion inhibitor for 1045 carbon steel in acidic medium (HCl). The bioactive compounds present in LP were isolated by liquid-liquid extraction using different solvents, such as methanol, water, chloroform, and hexane. Pyrooligneous liquid concentrations ranging from 100 ppm to 600 ppm were tested to determine its efficacy as a corrosion inhibitor (I.PL). The methanolic (I.LPM) and chloroform (I.PLC) extracts showed the highest efficiencies, reaching 95.32% and 96.32% at 400 ppm, respectively. The aqueous extract (I.LPW) achieved an efficiency of 72.97%, while the hexane extract (I.PLH) obtained 87.74%. Analytical techniques, including mass loss, electrochemical impedance spectroscopy and potentiodynamic polarization, indicated that I.LPM and I.PLC extracts formed robust protective layers, especially at high temperatures, following the Langmuir adsorption model. The results highlight the potential of LP as a sustainable and effective corrosion inhibitor for use in industrial applications, contributing to the valorization of eucalyptus by-products in environmentally responsible practices.