Grape Leaves and Ziziphus Spina-Christi, Extracts as a Green Inhibitors Corrosion for The Carbon Steel and Oil Pipelines in 1M H2SO4

Abstract

Metals suffer from corrosion by the surrounding fluids, which causes great economic losses and bad environmental effects, especially in oil pipelines or reservoirs. The extract of grape leaves (GL) and Sidr leaves, (Ziziphus spina-christi), (Zizi) were used as green corrosion inhibitors (CI) for carbon steel (CS), and Oil Pipelines in 1M H2SO4, these extracts showed varying capabilities in resisting corrosion. Corrosion rate was decreased with increase in inhibitor dose which could be due to enhanced surface coverage, as well as the effect of increasing the temperature on the percentage of the efficiency of inhibition, are decrease, and drawing the curves for that, as well as studying some physical properties related to the process of adsorption of extracts on the surface of (CS), such as the activation energy and entropy of the process of adsorption of the extracts on the surface of (CS), and calculating those values, and the extracts showed an efficiency that exceeded 90% at concentrations up to 400 ppm and a temperature of 313-343K. The activation energy associated with this process indicated surface interaction as the main mechanism and positive values of enthalpy change confirmed the endothermic nature. The potentiometric method showed the extent of voltage change with time for each concentration of extract of grape leaves for immersion time (2–24 h), and that the voltage increases with increasing concentration, which indicates a high ability of the inhibitor to adsorb to the metal..