Synthesis and application of corrosion inhibitor for hydrogen sulfide corrosion of steel

In this paper, the synthesis of PKA-1 brand oligomeric corrosion inhibitor based on polyethylene polyamine (PEPA) and crotonaldehyde has been done. In this synthesis, it is observed that the reaction efficiency is high when the molar ratio of the initial substances is 1:1 and the temperature is 50°C. The duration of the reaction is 2 h and dimethylformamide is used as a solvent. The structure of this synthesized compound has been studied by IR-spectrum methods. The inhibitory properties of the obtained PKA-1 brand corrosion inhibitor have been studied in the prevention of hydrogen sulfide corrosion of steel materials by gravimetric and electrochemical methods at different temperatures and time and at different concentrations of 50 mg/L, 75 mg/L, 100 mg/L and 150 mg/L. According to the obtained results, the inhibition efficiency increased as the inhibitor concentration increased, and the efficiency was 94.3% in OW (oil-water)+H2S (400 mg/L) medium at a concentration of 150 mg/L. Also, the thermodynamic and kinetic parameters of the adsorption mechanisms of this corrosion inhibitor on the steel surface are studied, and the adsorption of this corrosion inhibitor on the steel surface is studied using Temkin, Frumkin and Langmuir isotherms. According to the results, it was found that the adsorption process proceeds according to the Langmuir isotherm. In addition, the surface morphology of steel is studied and analyzed with the help of scanning electron microscope and atomic force microscope.