ATR-FTIR Model Development and Verification for Qualitative and Quantitative Analysis in MDEA–H2O–MEG/TEG–CO2 Blends

Abstract

A Fourier transform infrared (FTIR) spectroscopy method was developed to identify and quantify various components in an amine-based combined acid gas and water removal process. In this work, an attenuated total reflectance (ATR) probe was used. A partial least-squares (PLS) regression model was also developed using up to four components (methyl diethanolamine (MDEA)-H2O-CO2-ethylene glycol/triethylene glycol (MEG/TEG)), and it was successfully validated. The model was applied on thermally degraded CO2-loaded MDEA blends to predict the weight percentages of MDEA, H2O, CO2, and MEG or TEG to test the performance spectrum. The results confirmed that FTIR could be used as a simpler, quicker and reliable tool to identify and quantify various compounds such as MDEA, MEG/TEG, H2O and CO2 simultaneously in a combined acid gas and water removal process.