4886

4590

كارشناسي ارشد

خوردگي و حفاظت از مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1388

[هشت] ، 90ص: مصور، جدول، نمودار

ص.ع.به: فارسي و انگليسي

محمد علي گلعذار، كيوان رئيسي

15/10/88

احمد ساعتچي، محمود پيكري

1396/09/22

كتابنامه

مهندسي مواد

ID4590

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Control of corrosion in petroleum industries by using corrosion inhibitors Jaafar Aljourani aljourani@ma iut ac ir on May 4 2009 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiProf Mohammad Ali Golozar Dr Keyvan RaeissiAbstractAcid solutions such as hydrochloric and sulfuric acids are used in acidic processes in petroleum industries foracid cleaning of boilers and acidizing of oil wells To prevent the acid corrosion of metals inhibitors should beused In this work heterocyclic organic derivatives namely benzimidazole 2 methylbenzimidazole and2 mercaptobenzimidazole were used as corrosion inhibitor for carbon steel Polarization and electrochemicalimpedance spectroscopy EIS measurment were performed in the presence of benzimidazole 2 methylbenzimidazole and 2 mercaptobenzimidazole at concentrations of 50 100 150 200 and 250 ppm Theresults indicat that the inhibitors are adsorptive type inhibitors in both media The mechanism of inhibition isassumed by adsorption at metal solution interface and blocking the anodic and cathodic active sites Theinhibition efficiency increased with inhibitor concentration The higher values of equilibrium constant andstandard free energy of adsorption were obtained at the presence of 2 mercaptobenzimidazole indicating itshigher adsorptivity and higher inhibiting effect comparing benzimidazole and 2 methylbenzimidazole Theadsorption of the inhibitors obyes Langmuir adsorption isotherm The values of standard free energy indicat thatthe physical adsorption is more probable The inhibition efficiency of benzimidazole and its derivatives inhydrochloric acid was decreased with temperature at the rang of 25 55 C The activation energy of corrosion inpresence of inhibitors was more than that at the absence Indeed the enthalpy value of adsorption indicates thatthe physical adsorption is occured The synergistic effect of bromide ion are observed in the presence ofbenzimidazole and 2 methylbenzimidazole in sulfuric acid while this effect was negligible in the presence of 2 mercaptobenzimidazole The synergistic effect of bromide ion indicates that the adsorption of benzimidazole and2 methylbenzimidazole is physical while the chemical adsorption is more expected to occur in the presence of 2 mercaptobenzimidazole The inhibition effects of benzimidazole and 2 methylbenzimidazole in 1M HCl ishigher than that in 0 5M H2SO4 solution while the effect of 2 mercaptobenzimidazole in both media was almostunchanged This result indicates that the inhibition effects of 2 mercaptobenzimidazole is independent of thetype of acid anion while the effect of benzimidazole and 2 methylbenzimidazole is dependent to thetype of acid anion Impedance testes in hydrochloric acid proved the adsorption of the inhibitors Results obtainedindicate that the presence of mercapto and methyl group as the substituents in benzimidazole molecule isresponsible for improving the inhibition property of the molecule Key wordsBenzimidazole Corrosion inhibitors Acid solution Carbon steel Adsorption EIS

محمد علي گلعذار، كيوان رئيسي

احمد ساعتچي، محمود پيكري