CESAR1 Carbon Capture Pilot Campaigns at an Industrial Metal Recycling Site and Analysis of Solvent Degradation Behavior

Abstract

Carbon capture is an essential technology in the energy transition. Post-combustion carbon capture using amine solvents is the most advanced technology, with CESAR1, a mixture of 3 M 2-amino-2-methyl-1-propanol (AMP) and 1.5 M piperazine (PZ), currently being established as the state-of-the-art open solvent, for which an increasing amount of high-quality pilot results is becoming available. This study extends the amount of available CESAR1 solvent pilot data by discussing the results of two pilot campaigns conducted at a metal recycling facility (Umicore, Belgium) using a mobile CO₂ capture plant (TNO’s miniplant). The campaigns captured CO₂ from two flue gas sources: a blast furnace (804 h of operation) and a smelter (915 h of operation). This paper discusses the main results of both campaigns, including data for the accumulation of several relevant degradation products in the capture solvent. The stable operation and consistent degradation profiles observed in both campaigns display the strength of on-site, small-scale mobile pilot testing on real flue gases, which can derisk the implementation of a full-scale system on those specific flue gases. Additionally, the solvent degradation results of the Umicore campaigns are compared to two pilot campaigns described in the literature (the RWE and TCM campaigns), also using CESAR1 as the capture solvent. A novel methodology is proposed in this work to compare the solvent degradation results from pilots of different sizes. The results of this comparative analysis highlight the stability of the CESAR1 solvent, showing no sign of exponential degradation in any of the campaigns considered. Additionally, the role of NO₂ in oxidative solvent degradation is further clarified, as during the smelter campaign, higher NO₂ concentrations were reported (36.4 ppm on average) than for any of the other campaigns discussed in this study (0.5–2.35 ppm), and consequently, much higher solvent degradation rates were observed.