Universalism of inhibitors against hydrogen sulfide and carbon dioxide corrosion of carbon steel

Abstract

The universality of inhibitors is understood as their ability to inhibit several types of corrosion attack: hydrogen sulfide and carbon dioxide corrosion, hydrogen diffusion into metal, development of sulfate-reducing and other types of bacteria, negative impact on the mechanical properties of metals. Indicators of universalism of new inhibitor have been studied. Producer of the inhibiting compositions is Limited Liability Company «INCORGAZ» (S-Petersburg, Russia). The efficacy of the inhibitor in the concentration of 25 - 200 mg/L has been studied with respect to carbon steel in a highly mineralized chloride medium (pH= 6) and NACE medium (5 g/L NaCl, 0.25 g/L CH3COOH, pH =3.5) containing H2S (50-400 mg/L) and CO2 (1at) separately and together. The bactericidal properties of the inhibitor were studied with respect to sulfate-reducing bacteria in the Postgate medium. The investigations were carried out by the methods of linear polarization resistance, electrochemical impedance spectroscopy, gravimetry, potentiodynamic polarization. The protective effectiveness of the inhibitor reaches 80% in the presence of CO2 and 90% in hydrogen sulphide environments. The inhibitor repeatedly reduces the number of sulfate-reducing bacteria and the production of biogenic hydrogen sulfide and inhibits the diffusion of hydrogen into steel.

Application of electrochemical impedance spectroscopy to study hydrogen sulphide corrosion of steel and its inhibition: a review

“…And the value IE( R an ) most adequately corresponded to protective effects derived from the corrosion experiments [71]. In the presence of CI C dl ≤ 1 µF cm −2 , which as the authors of papers [63,71,72] supposed, indicated its multilayer adsorption. This is consistent with the data of other authors [67].…”

“…Protective properties of high amines (AMDOR-IK-7), their acetates and PKU-6, a product of condensation of urotropine with alkyl chloride (Table 2), at C in from 5 to 200 mg L −1 were also studied by Professor Tsygankova with colleagues in researches [60][61][62][63][64][65]. The experiments were conducted in media simulating oil-field water, without and with H 2 S (from 50 to 400 mg L −1 ).…”

“…It was discovered that protection by the amine acetates increased as pH decreased. It applies to pyridine bases as well [64].…”

“…It was discovered that protection by the amine acetates increased as pH decreased. It applies to pyridine bases as well [64].

Figure 16 The Keddam (a) and Mansfield equivalent circuits (c) and their modifications (b, d) [71].

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“…Imidazoline as a component of the inhibiting composition AMDOR-IK-6 and its derivatives (‘EM’ series inhibitors, Table 2) were also studied in [63,70–72]. The comparative interpretation of the EIS results was performed using 4 ECs: Keddam circuit and its modification (Figure 16(a,b)) [66], Mansfield circuit and its modification (Figure 16(c,d)).…”