Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors
| Main Author: | |
|---|---|
| Language: | English |
| Published: |
Ohio University / OhioLINK
2020
|
| Subjects: | |
| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1577092234789695 |
| id |
ndltd-OhioLink-oai-etd.ohiolink.edu-ohiou1577092234789695 |
|---|---|
| record_format |
oai_dc |
| spelling |
ndltd-OhioLink-oai-etd.ohiolink.edu-ohiou15770922347896952021-08-03T07:13:36Z Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors Dominguez Olivo, Juan M. Chemical Engineering Carbon dioxide corrosion mechanistic model corrosion inhibition organic synthesis Internal corrosion in pipelines is a significant issue in the upstream oil and gas industry. Corrosion engineers have developed strategies to mitigate corrosion, and among these, the use of organic corrosion inhibitors is one of the most widely used solutions. Corrosion inhibitors are substances that significantly reduce corrosion when added in small, typically ppm level, concentrations. Knowledge related to their efficiency, and associated mechanisms of inhibition, has been developed by conducting experiments in physicochemical conditions that simulate field environments during their application. Nonetheless, there is a lack of studies in the open literature that mechanistically define the effect of corrosion inhibitors on the kinetics of the electrochemical processes underlying corrosion. Consequently, the central objective of this research was to propose a mechanistic model that describes and predicts the effect of organic corrosion inhibitors on the electrochemical processes governing the carbon dioxide corrosion of mild steel. In order to develop the mechanistic model, corrosion studies included the electrochemical characterization of aqueous steel corrosion in the presence of known corrosion inhibitor packages (quaternary-ammonium-type and imidazoline-type) with techniques such as linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. During these experiments, the state-of-the-art knowledge on corrosion inhibition available in the open literature related to corrosion inhibition was insufficient to explain specific experimental observations satisfactorily. This situation led to the postulation of ad hoc hypotheses to explain the effect of the organic corrosion inhibitors’ molecular structure on the observed electrochemical kinetics for the corrosion process, namely, the effects of inhibitor alkyl tail length and head group. The hypotheses were tested with alkyl-benzyl-dimethylammonium (quat-type) corrosion inhibitor model compounds, synthesized in-house, with systematically increasing alkyl tail lengths (-C4H9 to -C16H33). With precise control of the purity and molecular structure of these compounds, activation energies associated with charge transfer kinetics of the CO2 corrosion process were determined in the presence and absence of the inhibitor model compounds. The results indicated that the activation energy associated with the electrochemical kinetics of corrosion increases proportionally to the alkyl tail length. The head group changes the activation energy and governs the kinetics of adsorption of inhibitor with the same alkyl tail length. These findings led to the development of an electrochemical model based on a modified Butler-Volmer equation combined with Langmuir adsorption kinetics. Such a model was tested and validated with experimental data (LPR corrosion rates, potentiodynamic polarization curves, and OCP measurements). As an outcome, the model exhibited a high degree of accuracy in the prediction of the corrosion rates, as well as how the associated mechanism was affected by the presence of the inhibitor model compounds. 2020-06-01 English text Ohio University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1577092234789695 http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1577092234789695 restricted--full text unavailable until 2022-06-01 This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
| collection |
NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Chemical Engineering Carbon dioxide corrosion mechanistic model corrosion inhibition organic synthesis |
| spellingShingle |
Chemical Engineering Carbon dioxide corrosion mechanistic model corrosion inhibition organic synthesis Dominguez Olivo, Juan M. Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors |
| author |
Dominguez Olivo, Juan M. |
| author_facet |
Dominguez Olivo, Juan M. |
| author_sort |
Dominguez Olivo, Juan M. |
| title |
Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors |
| title_short |
Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors |
| title_full |
Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors |
| title_fullStr |
Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors |
| title_full_unstemmed |
Electrochemical Model of Carbon Dioxide Corrosion in the Presence of Organic Corrosion Inhibitors |
| title_sort |
electrochemical model of carbon dioxide corrosion in the presence of organic corrosion inhibitors |
| publisher |
Ohio University / OhioLINK |
| publishDate |
2020 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1577092234789695 |
| work_keys_str_mv |
AT dominguezolivojuanm electrochemicalmodelofcarbondioxidecorrosioninthepresenceoforganiccorrosioninhibitors |
| _version_ |
1719456647372341248 |