Study of the Effect of Temperature on Activation Energy and Corrosion Rate of Mild Steel Using Green Inhibitor: “Posidonia Oceanica”

Abstract

Newly extract "posidonia Oceanica" derivatives with different concentrations 2 %, 4%, 6% and 8 % as a corrosion green inhibitor of mild steel in sea water at different temperatures 25, 40, 50 and 60 °C. The corrosion comes from a sea water environment leads to serious consequences of the corrosion problems by reaction with its environment process which has become a problem of worldwide especially at high temperature. The inhibition efficiency of the extract posidonia Oceanica was calculated and compared. The results obtained revealed that the inhibitor tested differently reduced the kinetics of the corrosion process of steel. Its efficiency increases with the concentration and attained 95.2 % at 8 %. The thermodynamic data of activation were determined. Posidonia Oceanica extract is adsorbed on the steel surface according to a Langmuir adsorption model. The change of activation energy values indicates that the adsorption is a physical situation. The negative value of (ΔH) indicates that the adsorption of inhibitors is an exothermic process. The effect of temperature on the inhibition efficiency in the absence and presence of posidonia Oceanica of all samples were obtained and expressed as; Ea and ΔH .