Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (8): 2099-2110.doi: 10.1016/j.cjche.2020.03.006

• Catalysis, Kinetics and Reaction Engineering • Previous Articles     Next Articles

Modeling the rate of corrosion of carbon steel using activated diethanolamine solutions for CO2 absorption

Lubna Ghalib1, Ahmed Abdulkareem2, Brahim Si Ali3, Shaukat Ali Mazari4   

  1. 1 Materials Engineering Department, Mustansiriyah University, Baghdad 14022, Iraq;
    2 Mathematics Science, Directorate General of Education Rusafa 1, Baghdad, Iraq;
    3 Department of Chemical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia;
    4 Department of Chemical Engineering, Dawood University of Engineering and Technology, Karachi 74800, Pakistan
  • Received:2019-08-20 Revised:2020-02-09 Online:2020-08-28 Published:2020-09-19
  • Contact: Shaukat Ali Mazari

Abstract: A mechanistic model is developed to investigate the influence of an activator on the corrosion rate of carbon steel in the absorption processes of carbon dioxide (CO2). Piperazine (PZ) is used as the activator in diethanolamine (DEA) aqueous solutions. The developed model for corrosion takes into consideration the effect of fluid flow, transfer of charge and diffusion of oxidizing agents and operating parameters like temperature, activator concentration, CO2 loading and pH. The study consists of two major models: Vapor-liquid Equilibrium (VLE) model and electrochemical corrosion model. The electrolyte-NRTL equilibrium model was used for determination of concentration of chemical species in the bulk solution. The results of speciation were subsequently used for producing polarization curves and predicting the rate of corrosion occurring at the surface of metal. An increase in concentration of activator, increases the rate of corrosion of carbon steel in mixtures of activated DEA.

Key words: CO2 capture, CO2 corrosion, Carbon steel, Diethanolamine, Piperazine, Electrochemical model