CO2 capture 2-amino-2-methyl-1-propanol/piperazine degradation. Comparison of BECCS and cement production

Blends of 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ), such as CESAR1, are emerging solvents for post-combustion CO 2 capture, yet their long-term degradation behaviour under flue gas exposure from biomass combustion remains limited in the literature. A pilot plant was operated for 3300 h at a woodchip-fired power plant using a CESAR1 solvent. Solvent samples were collected and analysed for amines, heat-stable salts, and metals using ion chromatography and spectrophotometry. Results were benchmarked against a previous campaign using the same pilot on cement-plant flue gas. The PZ concentration remained relatively stable throughout the campaign, whereas the AMP concentration gradually decreased with operating time. Oxidative and thermal degradation products accumulated in the lean solvent, with concentrations of glycolic acid reaching 526 ppm after 2000 h, acetate reaching 418-443 ppm, formate increasing to 1795 ppm after 3000 h, and oxalate increasing to 200 ppm towards the end of the campaign. The concentrations of inorganic anions reflected differences in flue gas composition. Nitrate concentrations increased more slowly during biomass operation (600-700 ppm after 3300 h) than during the cement flue gas campaign, while sulphate concentrations reached approximately 260 ppm. Dissolved iron concentrations remained low during biomass operation but reached tens of ppm during the cement campaign. The results demonstrate that CESAR1 can be operated for extended periods on biomass-derived flue gas with comparatively low concentrations of nitrate and iron. However, organic acids and sulphate continued to accumulate over time, highlighting the importance of monitoring solvent degradation and HSS formation during long-term operation.