Demonstration of CO2 Capture Process Monitoring and Solvent Degradation Detection by Chemometrics at the Technology Centre Mongstad CO2 Capture Plant: Part II

In this work (Part II), we present quantitative monitoring of degradation for 30 wt % aqueous monoethanolamine (MEA) solvent using the residual Fourier transform infrared (FTIR) spectra extracted from the partial least-squares regression (PLS-R) models developed in Part I. The PLS-R models of Part I cover monitoring of TIC (total inorganic carbon, i.e., solvent CO2 capture capacity) and TA (total alkalinity, i.e., solvent capture “strength”) of continuously degrading MEA solvent; these models incorporate a methodological hierarchy for continuous model update throughout the entire campaign to address the ongoing solvent degradation. Both Parts I and II of our work are based on a 1960-h test campaign conducted at the Technology Centre Mongstad, Norway, in 2015 using 30 wt % aqueous MEA solvent. In Part II, residual spectra were extracted and used to formulate prediction models for in-line followup of degradation species groups: (i) total heat-stable salt (HSS) species and (ii) total amine degradation products. This new tool for continuous solvent degradation quantification can supplement the current practice of indirect estimation of when to start and/or stop solvent reclaiming.