摘要
The novelty of this paper is the analysis in a medium containing sulfide ion due to the generation of this ion in petroleum industries, in the refining stage (the sulfide ion is also present on the produced water). The performance of 1-hydroxyethylidene-1,1-diphosphonic acid inhibitor (HEDP) was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurements in a dissolution of AISI 304 stainless steel immersed in a solution containing chloride and sulfide ions. The protection of the stainless was increased with the addition of divalent cations (Ca<sup>2+</sup>, Zn<sup>2+</sup>, and Mg<sup>2+</sup>). Potentiodynamic polarization studies have shown that the inhibitor alone has anodic protection, but the addition of Ca<sup>2+</sup> (10 mg<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>L<sup>-1</sup>) favors the cathodic protection, and the addition of Zn<sup>2+</sup> (20 mg<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>L<sup>-1</sup>) and Mg<sup>2+</sup> (10 mg<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>L<sup>-1</sup>) mixed-type is observed. Electrochemical impedance spectroscopy was performed at three distinct potentials: -0.3 [V <i>vs.</i> SCE], <i>E</i><sub>corr</sub> [V <i>vs.</i> SCE], and 0.1 [V <i>vs.</i> SCE]. This revealed that calcium is responsible for favoring the formation of the film and the other elements (zinc and magnesium) favor the stabilization of the protective film. Scanning electron microscopy analysis revealed that the addition of cations provided the adsorption of HEDP on the metal surface. Weight loss results showed that the presence of zinc in a solution containing HEDP favored greater inhibitor efficiency (Zn<sup>2+</sup> <i>η</i><sub>m</sub> = 85.2% and for Mg<sup>2+</sup> <i>η</i><sub>m</sub> = 70.4%).
The novelty of this paper is the analysis in a medium containing sulfide ion due to the generation of this ion in petroleum industries, in the refining stage (the sulfide ion is also present on the produced water). The performance of 1-hydroxyethylidene-1,1-diphosphonic acid inhibitor (HEDP) was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurements in a dissolution of AISI 304 stainless steel immersed in a solution containing chloride and sulfide ions. The protection of the stainless was increased with the addition of divalent cations (Ca<sup>2+</sup>, Zn<sup>2+</sup>, and Mg<sup>2+</sup>). Potentiodynamic polarization studies have shown that the inhibitor alone has anodic protection, but the addition of Ca<sup>2+</sup> (10 mg<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>L<sup>-1</sup>) favors the cathodic protection, and the addition of Zn<sup>2+</sup> (20 mg<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>L<sup>-1</sup>) and Mg<sup>2+</sup> (10 mg<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>L<sup>-1</sup>) mixed-type is observed. Electrochemical impedance spectroscopy was performed at three distinct potentials: -0.3 [V <i>vs.</i> SCE], <i>E</i><sub>corr</sub> [V <i>vs.</i> SCE], and 0.1 [V <i>vs.</i> SCE]. This revealed that calcium is responsible for favoring the formation of the film and the other elements (zinc and magnesium) favor the stabilization of the protective film. Scanning electron microscopy analysis revealed that the addition of cations provided the adsorption of HEDP on the metal surface. Weight loss results showed that the presence of zinc in a solution containing HEDP favored greater inhibitor efficiency (Zn<sup>2+</sup> <i>η</i><sub>m</sub> = 85.2% and for Mg<sup>2+</sup> <i>η</i><sub>m</sub> = 70.4%).
作者
Juliana Panceri Franco
Josimar Ribeiro
Juliana Panceri Franco;Josimar Ribeiro(Laboratório de Pesquisa e Desenvolvimento em Eletroquímica, Departamento de Química do Centro de Ciências Exatas da Universidade Federal do Espírito Santo, Vitória, Brazil)
