Acid Corrosion Inhibitor from Tobacco Waste for Steel of Oil Pipes

Organic inhibitors are applied in the process of cleaning of steel oil pipelines using mineral acids. To reduce the cost of technology and improve the environment, it is proposed here to use nicotine contained in tobacco waste. A manufacturing technology for an inhibitor of the acid corrosion of steel oil pipelines has been developed by the authors earlier. Using an aqueous solution of benzoic acid, an inhibitors was obtained by extracting nicotine and related substances from tobacco waste: cigarette butts and cigarettes (Inhibitor 1), tobacco dust powder (Inhibitor 2) during the production of tobacco. The technology applies the opposite charge of benzoic acid to the charge of nicotine and its hydrotropic properties. The yield of nicotine during extraction from tobacco waste and the effectiveness of inhibitory protection of PSL-1 steel used for oil pipelines were investigated. Gas chromatography-mass spectrometry was used to study the composition of the inhibitors. Gravimetric and electrochemical methods were applied to determine its efficiency. The behavior of the polarization curves remained the same in the absence and in the presence of the inhibitors, but the curves shifted towards a lower log i in the presence of the inhibitors, which indicates that the inhibitor molecules slow down the corrosion process. The inhibitors act as a mixed type inhibitor, affecting both anodic and cathodic reactions. The efficiency of the inhibitor protection of PSL-1 steel was 92–96%. Corrosion inhibition results obtained by the weight loss method and electrochemical measurements are in good agreement.