Experimental Study on the Carbon Capture Performance of Aqueous Monoethanolamine Solution in the Presence of Polyvinyl Pyrrolidone (PVP) as an Additive

Abstract Carbon capture and sequestration is considered one of the critical negative emission technologies with the potential to limit global warming. Chemical absorption using amine-based solvents has been widely used for the large-scale capture of CO2. However, the technology suffers major drawbacks in terms of high regeneration energy requirement and limited CO2 loading. In this work, PVP – an inexpensive, non-toxic, and biodegradable polymer is explored as a potential additive to intensify the carbon capture performance of 30 wt% aqueous monoethanolamine (MEA) solutions. The CO2 absorption and desorption experiments were carried out at 40 °C and 75 °C, respectively. The 0.1% PVP-MEA solution demonstrated a significant increase of about 20.35% in the CO2 absorption capacity, followed by 0.05% PVP-MEA (18.02%) and 0.02% PVP-MEA (17.93%) compared to the blank MEA solution. However, during desorption, the amount of CO2 desorbed from the PVP solutions was significantly lower compared to blank MEA, indicating interaction between PVP and CO2. Also, the addition of PVP was found to lower the surface tension of the solution, contributing to the improved CO2 absorption while also drastically improving the absorption kinetics. The FTIR analysis of CO2 absorbed liquid samples revealed that both blank MEA and 0.1% PVP-MEA solutions exhibit similar presence (concentration) of the carbamate species, indicating that the excess CO2 captured by the PVP-MEA solution is likely physically adsorbed or bound by the PVP molecule in the liquid phase.