Intensification of Sono-Assisted CO₂ Stripping/Carbon-Rich Solvent Regeneration by Fe₂O₃ Hydrophobic Micronized Particles

Abstract

In 2020, the amount of CO2 generated by coal combustion was estimated to be 15.32 Gt CO2. In a solvent-based postcombustion CO2 capture (PCCC) process, the solvent regeneration/CO2 stripping process uses thermal energy to regenerate the solvent. It has an adverse impact on the solvent’s thermal stability, besides causing a significant quantity of solvent loss and a high energy demand. In recent times, one method for PCCC cost savings has emerged: sono-assisted solvent regeneration/CO2 stripping. The present work focuses on enhancing the high-frequency ultrasound-assisted aqueous carbon-rich 30 wt % monoethanolamine (MEA) solvent regeneration/CO2 stripping process using Fe2O3 hydrophobic micronized particles (concentrations varied in the ranges of 0.005, 0.01, 0.05, 0.1, and 0.2 wt %) in a controlled-temperature environment at 12 °C using 360 kHz, 470 kHz, and 1 MHz (streaming-dominant frequencies). From the investigation, the lowest concentration (0.005 wt %) of micronized particles shows maximum enhancements of 12.29, 20.93, and 33.62%, thereby decreasing the solvent sensible energy requirements by 1.26, 2.4, and 2.9 times than without micronized particles for the tested frequencies. In addition, the observed CO2 stripping rate is much higher when compared to the case without micronized particles. The stripping efficiency is observed to be high in the initial stages of sonication (5 min).

Performance of Water-Lean Solvent for Postcombustion Carbon Dioxide Capture in a Process-Intensified Absorber: Experimental, Modeling, and Optimization Using RSM and ML

“…The advantages of alkanolamines include a high reaction rate, high efficiency, reasonable price, and chemical stability. The disadvantages of alkanolamines include high energy consumption, low amine absorption capacity, sensitivity to oxygen, and corrosion in equipment . Among alkanolamines, monoethanolamine (MEA) is a crucial absorbent for removing carbon dioxide, which has advantages such as high reactivity, low solvent cost, low molecular weight, and high absorption capacity based on weight.…”