Nonaqueous MEA/PEG200 Absorbent with High Efficiency and Low Energy Consumption for CO2 Capture

CO2 capture by stripping with aqueous amine is a well-understood and widely employed technology. However, there still exist several drawbacks in the practical applications, such as high energy consumption and serious equipment corrosion. In this paper, an organic monoethanolamine/poly(ethylene glycol) 200 (MEA/PEG200) absorbent with low specific heat capacity, low vapor pressure, and a high boiling point was developed to substitute the aqueous amine systems. The absorption rate and capacity, the desorption rate, and regeneration efficiency, as well as the thermal stability of the absorbent were systematically investigated. For instance, the 3 M MEA/PEG200 absorbent exhibited the highest desorption rate (838 mg(CO2)/(L-sol.min)) and excellent cyclic stability (deviation < 4%), which was much superior to the 3 M MEA/H2O absorbent (447 mg(CO2)/(L-sol.min)). In addition, the desorption energy consumption of the MEA/PEG200 absorbent was 33% lower than that of the MEA/H2O. Moreover, both fresh and CO2-rich MEA/PEG200 solutions exhibited only slight corrosion to carbon steels even after being immersed for 400 days. Therefore, this low-energy-consuming and anticorrosive MEA/PEG200 absorbent reveals the potential for industrial CO2 capture.

Automated summary

This study developed an MEA/PEG200 absorbent for CO2 capture with low energy consumption and anticorrosive properties, demonstrating its potential in industrial applications.