IR Monitoring of Absorbent Composition and Degradation during Pilot Plant Operation

• Published in: Industrial & engineering chemistry research Vol. 59; no. 15; pp. 7080 - 7086
• Main Authors: Puxty, Graeme, Bennett, Robert, Conway, Will, Webster-Gardiner, Mike, Yang, Qi, Pearson, Pauline, Cottrell, Aaron, Huang, Sanger, Feron, Paul, Reynolds, Alicia, Verheyen, Vince
• Format: Journal Article
• Language: English
• Published: American Chemical Society 15.04.2020
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.9b05309

The monitoring of the absorbent during the operation of CO2 separation processes is a necessary and challenging task. The most common absorbent used is an aqueous amine solution. Traditional approaches to analysis such as titration and chromatography are time-consuming and only provide limited information. This hinders the ability of process operators to rapidly respond to changes in operating conditions. In this work, a combination of infrared (IR) spectroscopy and principle component regression (PCR) analyses have been demonstrated as a rapid and reliable technique to determine the composition of an absorbent during a pilot plant campaign at a brown coal power station. The concentration of amine, a degradation product, CO2, and water was monitored throughout the campaign by a method that provided results in minutes. The results were verified by independent sample analysis using acid–base titration, high-performance liquid chromatography (HPLC), and 13C NMR spectroscopy. It was necessary to use spectral windowing when building the IR-PCR model, but this resulted in a robust and reliable method that has been demonstrated to work in a real-world process environment.