Olive pomace extract (OPE) as corrosion inhibitor for steel in HCl medium

Abstract

ObjectiveTo explore the possibility of reuse olive pomace extract as a corrosion inhibition of steel in an acidic medium (HCL, 1 mol/L), and to compare the inhibitory effect of olive pomace (OP) samples collected from three extraction process of olive oil: press process, continuous process three-phase and continuous process two-phase and olive pomace continuous process two-phase without stone and stone of olive (both fractions were separated by mill) in the eastern region of Morocco. MethodsThe electrochemical behavior of the C38 steel in HCl medium in the absence and presence olive pomace was studied by gravimetric and electrochemical techniques such as potentiodynamic polarization, linear polarization and impedance spectroscopy. The effect of temperature was also studied. The experimental data with several adsorption isotherms at different temperatures were tested to determine the standard free energy of adsorption process and the adsorption mode of inhibitor on the surface of the steel were studied. ResultsThe samples of the olive pomace tested in the corrosion experiment have a very complex and heterogeneous physicochemical composition. They contain a variety of organic and inorganic compounds of very different nature and concentration, allowing the olive pomace play a very important role in anti-corrosion activity. The inhibition efficiency increased with increased olive pomace concentration to attain a maximum value of 92.1% at 1.4×10−5 with small differences among the other samples of olive pomace. ConclusionsThe use of solid waste (pomace) of crushing olives (oil mills) as green inhibitors in the fight of corrosion plays a dual function, firstly, destituting the pollution of the receiving environments (soil, water, etc.) and on the other hand, a recovery of components (bioactive) such as phenolic compounds.