Protection against corrosion of API 5L X70 carbon steel intended to petroleum industry by green inhibitor: SchinusMolle Resin as an eco-friendly inhibitor.

Abstract

Corrosion inhibitors used in the petroleum industry are characterized as toxic, carcinogenic, and expensive materials in addition to the difficulty of their decomposition after use. Currently, studies in this field are focused on finding alternatives characterized by: non toxicity, biodegradability, low price and availability from renewable sources. All these properties are available in natural organic compounds. Therefore, a study was conducted about the inhibition efficiency of the Bark Resin of Shinus Molle (BRSM) as an API 5L X70 steel corrosion inhibitor in hydrochloric acid and sulfuric acid by using electrochemical techniques and surface analysis (SEM). Also, the synergetic effect between the iodine ion (KI) and the inhibitor (BRSM) has been studied. The results show that the inhibitor acts as a mixed inhibitor with an inhibition efficiency of 94% in the hydrochloric acid and 70% in the sulfuric acid medium. The adsorption of BRSM inhibitor on steel surface follows Langmuir isotherm adsorption. The surface analysis results also show a high inhibition efficiency of the bark resin of Shinus molle on the steel surface (API 5L X70).Therefore, there is a great agreement between the results of electrochemical techniques and the results of surface analysis.