Dantas, Tereza Neuma de CastroPinheiro, Gleidson Lima2016-05-122016-05-122014-08-15PINHEIRO, Gleidson Lima. Avaliação da eficiência de um inibidor comercial livre e dissolvido em microemulsão na corrosão do aço API 5L A210. 2014. 89f. Dissertação (Mestrado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2014.https://repositorio.ufrn.br/jspui/handle/123456789/20434Pipelines suffer from chemical, under tension, and other kinds of corrosion mechanisms, as well as electrochemica l corrosion caused by the existing large amount of brine (water and chlorides) in the produced fluids. The goal of this work is to research the efficiency of a commercial corrosion inhibitor, used in pipelines on the oil industry, on the corrosion inhibition of the API 5L A210 iron, which is widely used on the overland pipelines constructions, acting alone and in a mixture with micro emulsion (ME) on a [1:1] ratio. The ME was obtained from the following constituents: tap water (aqueous phase), kerosene (oily phase), n-butanol (co-surfactant), and UNT L90 (surfactant). We observed the formation of protective film on the steel surface as an inhibitor’s protection mechanism. The experiments were formulated in saline solutions with 3% of NaCl that functioned as aggressive environment, on the presence and absence of gas bubbling (CO2), in room temperature (25ºC). The studied inhibitor exhibits in its active phase quaternary ammonium compounds and imidazoline derivatives, which means it is a film-forming inhibitor. The inhibition efficiency results are evaluated by experimental data of corrosion current density by the electrochemical technique of linear polarization with Talef extrapolation. The inhibitor exhibit two distinct behaviors: in medium of saturation with CO2 we observed an increase of inhibition by blending the commercial additive with the micro-emulsion, and in medium without saturation of CO2 we observed a higher efficiency when the inhibitor was acting singly. We also could find that the excess of dissolved CO2 in the working solution resulted in an increase of the corrosion rate, compared to similar experiments in the absence of continuous bubbling of CO2. The best efficiencies were observed in the experiments with concentration of 40ppm without bubbling, and 200ppm when the experiments were performed in the presence of bubbling with CO2. The experimental data fitted to the Langmuir model, suggesting the formation of a film made of monolayers.porAcesso AbertoAço carbonoAdsorçãoInibidores de corrosãoTensoativosMicroemulsãomasterThesisCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA