Carbon-rich solvent regeneration in solvent-based post-combustion CO2 capture process (PCCC): Process intensification by megasonics

Abstract

Global greenhouse gas emanations from fossil-fuel combusting for power-generation alone contribute 9.795 gigatonnes (Gt) in 2014. There is a tremendous focus on global carbon capture researchers to cut down these emissions significantly. Chemical absorption is widely used and the use of monoethanolamine (MEA) was generally preferred. However, MEA solutions were not without problems. For example, equipment deterioration due to O2 presence, high energy for solvent-regeneration, solvent degradation and formation of undesired harmful by-products inhibits the solvent's cyclic capacity. To address these issues megasonics-assisted (1 MHz - tank-type) solvent regeneration process had been investigated experimentally. The results revealed that low regeneration temperature (<45 °C), less condenser duty, the potential for sensible heat saving, no reboiler is required facilitates capital and maintenance saving, no significant colour change after regeneration and loss of absorption capacity after regeneration was 3.7 times lower than the conventional. In addition, similar regeneration energy (20.20 KJ/mol CO2) but with 3.5 times lower nominal power input than the conventional regeneration method. Furthermore, physicochemical characterization of the solvent before and after absorption and regeneration followed by 13C NMR spectra analysis was also discussed.