Synthesis and study of the protective properties of the product of the reaction of glyoxal, ammonia, and acetaldehyde against hydrogen sulfide corrosion of carbon steel in model stratum waters

The G. Debus-B.L. Radzishevsky reaction with participation of glyoxal, ammonia, and acetaldehyde made it possible to obtain a product exhibiting inhibitory activity.The composition of the product was analyzed by IR spectroscopy and chromato-mass spectrometry.The inhibitory activity is due to the presence of nitrogen-containing substances, including imidazole and its derivatives.The corrosion inhibitory effect was studied against carbon steel corrosion in NACE and M1 model stratum waters saturated with H2S.The study was carried out by the gravimetry, potentiodynamic polarization and impedance spectroscopy methods.According to gravimetry, the protective effect (Z) of the product at a concentration of 200 mg/L is about 60% in the NACE medium and 70% in M1 medium containing 400 mg/L H2S at an experiment duration of 24 hours.Polarization measurements show higher Z values equal to 83% and 98%, respectively.The deceleration of corrosion is due to the inhibition of both partial electrode reactions in the NACE medium and the anodic reaction in the M1 solution due to the adsorption of the product components on the metal in accordance with the Langmuir isotherm.The calculated value of the free energy of adsorption equal to 28.5 kJ/mol indicates the physical adsorption of inhibitory components with a certain amount of chemisorption.