A combination of analytical instrumentation and multivariate statistics is widely applied to improve in-line process monitoring. Currently, postcombustion CO2 capture (PCC) technology often involves the use of multiamine based chemical reagents for carbon dioxide removal from flue gas. The CO2 capture efficiency and overall process performance may be improved by introduction of the chemometrics analytical methods for flexible and reliable process monitoring. In this study, six variables were measured (conductivity, pH, density, speed of sound, refractive index, and near-infrared absorbance spectra). A compact data-collecting chemometric setup was constructed and installed at an industrial pilot plant for real-case testing. This setup was applied to the characterization of CO2 absorption into aqueous 2-amino-2-methyl-1-propanol (AMP) activated by piperazine (PZ) as the absorption agent. A partial least-squares (PLS) regression model was calibrated and validated based on the measurements conducted in the la...