Development of the Methodology for Corrosion Inhibitor Persistency Studies in Batch Inhibition
Abstract
The objective of this study was to develop a methodology for batch inhibition studies that can better simulate the batch treatment in the field with the ability of removing all the inhibitor residuals from the system and have no oxygen contamination. Model compounds and commercial inhibitors were used to validate the methodology and investigate the effects of solvent, tail length, temperature, and contact time on CI persistency. The setup uses a large supply of CO2-sparged uninhibited brine to continuously dilute the test cell at a constant flow rate. The test cell uses a 2-liter glass cell with a three-electrode setup, a 300 gallon tank, gas sparging ports, heating controls, fluid circulation, and a purged outlet container for the waste solution. All the system is sparged and deoxygenated with CO2 prior to the test. Then inhibitor is applied in situ on the prepared API 5L X65 steel rotating cylinder electrode (RCE) inside the empty deoxygenated glass cell using a special holder and vial. After the glass cell is deoxygenated again, uninhibited brine is introduced to the system and rotation is started when the specimen is totally immersed in the solution. Each batch inhibition test was operated at 1 bar, pH 4.00 ± 0.10 with the RCE at 1000 rpm. OCP, EIS and LPR measurements were conducted every 20 minutes. Tests were run at 30°C with excursions to 45°C to test persistency. Tests for persistency of each inhibitor lasted from a few hours to more than 1 week.
Keywords:
CO2 Corrosion, Corrosion Inhibitor, Inhibitor Persistency, Batch Treatment
Status
Graduate
Department
Chemical and Biomolecular Engineering
College
Russ College of Engineering and Technology
Campus
Athens
Faculty Mentor
Singer, Marc
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Development of the Methodology for Corrosion Inhibitor Persistency Studies in Batch Inhibition
The objective of this study was to develop a methodology for batch inhibition studies that can better simulate the batch treatment in the field with the ability of removing all the inhibitor residuals from the system and have no oxygen contamination. Model compounds and commercial inhibitors were used to validate the methodology and investigate the effects of solvent, tail length, temperature, and contact time on CI persistency. The setup uses a large supply of CO2-sparged uninhibited brine to continuously dilute the test cell at a constant flow rate. The test cell uses a 2-liter glass cell with a three-electrode setup, a 300 gallon tank, gas sparging ports, heating controls, fluid circulation, and a purged outlet container for the waste solution. All the system is sparged and deoxygenated with CO2 prior to the test. Then inhibitor is applied in situ on the prepared API 5L X65 steel rotating cylinder electrode (RCE) inside the empty deoxygenated glass cell using a special holder and vial. After the glass cell is deoxygenated again, uninhibited brine is introduced to the system and rotation is started when the specimen is totally immersed in the solution. Each batch inhibition test was operated at 1 bar, pH 4.00 ± 0.10 with the RCE at 1000 rpm. OCP, EIS and LPR measurements were conducted every 20 minutes. Tests were run at 30°C with excursions to 45°C to test persistency. Tests for persistency of each inhibitor lasted from a few hours to more than 1 week.