Understanding 2-Ethanolamine Degradation in Postcombustion CO₂ Capture

Abstract

2-Ethanolamine (MEA) degradation has been studied under varying conditions of relevance to postcombustion CO 2 capture. Degradation experiments performed in the laboratory were chosen to be representative of the conditions in a CO 2 capture plant facility. The thermal degradation of MEA was investigated in closed-batch experiments at 135 °C at different loadings. MEA degradation was also studied in oxidative conditions without additives or by adding FeSO 4 /fly ash. These experiments were compared with three MEA campaigns performed in pilot plants at Tiller (Norway), Esbjerg (Denmark), and Longannet (U.K.). The same analytical procedures were used to identify and quantify the main degradation compounds. Mechanisms are also proposed to account for the observed degradation products. For the Tiller campaign 99.7% of nitrogen containing compounds in the liquid at the end of the campaign was accounted for by the solvent and quantified degradation products.

Oxidative degradation of 2-ethanolamine: The effect of oxygen concentration and temperature on product formation

“…Thermal degradation has been studied by several research groups over a long period of time (Davis and Rochelle, 2009;Eide-Haugmo, 2011;Lepaumier et al, 2009a;Polderman et al, 1955) while oxidative degradation has received increased attention the last decade (Goff and Rochelle, 2004;Lepaumier et al, 2009;Rooney et al, 1998;Supap et al, 2001) as it was discovered that oxidative degradation compounds are the main products under real plant conditions (da Silva et al, 2012;Lepaumier et al, 2011a;Strazisar et al, 2003). Increased insight into the degradation mechanisms, through knowledge of stoichiometry, kinetics, and chemical pathways, may result in methods for eliminating or strongly reducing degradation.…”

“…Either the amine loss was studied working in a closed-batch reactor at elevated temperatures and oxygen pressures (Lepaumier et al, 2009;Supap et al, 2001;Wang and Jens, 2011), or in an open-batch reactor at 55 °C where the CO2-loaded amine solution would be sparged with a wet gas blend of CO2 and air (da Silva et al, 2012;Goff and Rochelle, 2004;Lepaumier et al, 2011a;Lepaumier et al, 2011b). Lately there has been increased focus on the effect of temperature swing under industrial operation and an integrated solvent degradation apparatus (ISDA) was developed where the solvent is exposed to both oxidative and thermal degradation conditions in a single system (Closmann and Rochelle, 2011).…”

Oxidative degradation of amines using a closed batch system

“…The amine quantification for all amines, except MEA, was performed without internal standard. System and methods used for LC-MS analysis (alkylamine, ammonia, degradation compounds, amine, full scan) are described in more details by da Silva and Vevelstad (da Silva et al, 2012;. Details for the alkylamine and ammonia analysis for MEA experiment 1, KSAR and KGly on GC-MS are described by Vevelstad , while more thorough details on method and system used for the GC-MS analysis (MEA, MMEA, DMMEA, KSAR) of degradation compounds are given by Lepaumier (Lepaumier et al, 2011b).…”

“…Thermal degradation with CO2 was studied by Davies, Lepaumier and Eide-Haugmo (Davis, 2009;Eide-Haugmo, 2011;Lepaumier et al, 2009a) and oxidative degradation by Lepaumier (Lepaumier et al, 2009b). Increased attention on oxidative degradation was seen after pilot plant samples showed high degree of similarity to degradation compounds found in oxidative degradation experiments (da Silva et al, 2012;Lepaumier et al, 2011a;Strazisar et al, 2003). The oxidative degradation experiments reported have been performed in variations of two setups, either in a closed-batch reactor at elevated temperature and oxygen pressure (Lepaumier et al, 2009b;Supap et al, 2001;Wang and Jens, 2011) or in an open-batch reactor at 55 °C, where the solution would be sparged with a wet gas blend of CO2 and O2/air (da Silva et al, 2012;Goff and Rochelle, 2004;Lepaumier et al, 2011b;Sexton and Rochelle, 2011).…”

“…The amines were chosen based on structure. The setup was constructed to introduce new aspects to the previous open batch system described in earlier publications (da Silva et al, 2012;. Both gas and liquid phase analyses were performed.…”