Date of Graduation

Spring 2017

Document Type

Honors Research Project

Degree Name

Bachelor of Science


Corrosion Engineering - Cooperative Education

Research Sponsor

Dr. Hongbo Cong

First Reader

Dr. Rajeev Gupta

Second Reader

Dr. Qixin Zhou


The effectiveness of Benzalkonium chloride (C14) as a corrosion inhibitor for mild steel in an aqueous CO2 environment was studied for dual use. It is a known biocide and currently untested corrosion inhibitor. Potentiodynamic polarization was used to determine the anodic and cathodic reaction kinetics through analysis of the potentiodynamic curves and the corrosion current densities. Electrochemical impedance spectroscopy (EIS) was utilized to analyze the surface characteristics through analysis of the Nyquist and Bode plots. C1010 and C1018 mild steel were tested in a 200mL jacketed Gamery cell, and purged with CO2 (99.9%). Temperature effects were studied and ranged from 20oC, 40oC, 60oC, and 80oC. The test solution was varied between 0.1 wt. %, and 1.0 wt. %, NaCl and deionized water (18.2MΩ cm). Different concentrations of inhibitor were utilized based upon the critical micelle concentrations of Benzalkonium chloride (C14). It was found that the CO2 corrosion of mild-steel in NaCl environments was under both mixed charge transfer and mass transfer control. It is unclear if Benzalkonium chloride (C14) was effective at mitigating CO2 corrosion because no significant reduction of corrosion rate was observed when compared to non-inhibited studies.