Pilot-scale assessment of a phase-change CO2 capture solvent and process in the presence of sulfuric and nitric ions

• Pilot-scale evaluation of novel phase-change solvent S 1 N/DMCA with H 2 SO 4 and HNO 3. • Comparison to MEA with the same pollutant concentration and with pure S 1 N/DMCA. • Pollutants reduce absorption efficiency by 7.5%, cyclic capacity by 23 %, and increase regeneration energy by up to 20 %. • S 1 N/DMCA exhibits 70 % higher cyclic capacity and 60 % lower energetic requirements than MEA. Phase-change solvents (PCS) are a promising alternative for reducing the high energy requirements of post-combustion CO 2 capture processes. This work presents the pilot-scale evaluation of the novel PCS N‐cyclohexyl‐1,3‐propanediamine (S 1 N)/N,N-dimethylcyclohexylamine (DMCA) for CO 2 absorption/desorption in the presence of sulfuric and nitric anions that are found in industrial flue gases. The testing is performed by dissolving a total of 1.7 wt% of sulfuric and nitric acid in the solvent bulk, which corresponds to a large concentration of pollutants that may accumulate in the solvent after long operation. Absorption and regeneration efficiency, cyclic capacity, reboiler duty, and regeneration energy requirements are investigated as key performance indicators (KPI) for the capture process. The performance of S 1 N/DMCA is investigated with and without the anions for 5, 9 and 12 vol% CO 2 concentrations in the flue gas and is compared with the benchmark aqueous monoethanolamine (MEA) 30 wt% in the presence of anions. The results indicate that the anion pollutants induced a 7.5 % reduction of absorption efficiency, 23 % reduction of cyclic capacity, up to 35 % increased reboiler duty, and up to 20 % increased regeneration energy requirements. However, the PCS still achieved 70 % higher cyclic capacity and 60 % lower energetic demands compared to MEA.