DBU-Glycerol Solution: A CO₂ Absorbent with High Desorption Ratio and Low Regeneration Energy

Abstract

1,.0]-undec-7-ene (DBU)-glycerol solution is employed as a promising CO 2 absorbent. The regeneration of the CO 2 -loaded solution is of vital importance for its commercialization. It was investigated and compared with 30 wt % monoethanolamine (MEA). Variables affecting the absorption and desorption processes were studied, including the solvent composition, reaction temperature, and agitation. It shows that the absorption capacity for DBU-glycerol is comparable with 30 wt % MEA, and the desorption ratio for CO 2 -loaded DBU-glycerol mixture can reach as high as 95% in 60 min, 363 K at the 3:1 molar ratio of DBU to glycerol, while it is only 68% even after 165 min for CO 2 -saturated 30 wt % MEA. DBU-glycerol solution has higher cycling CO 2 loading than 30 wt % MEA. Its cyclic capacity could keep above 90% after 10 cycles of absorption−desorption experiments. The desorption reaction is irreversible at the initial stage, and the reaction rate is expected as a first-order reaction from 349 to 377 K, and the apparent activation energy is 68.94 kJ/mol. Moreover, the heat duty of the reboiler during regeneration is estimated to be reduced by about 27% when compared with 30 wt % MEA.

Direct Methanation of CO2 in Biogas with Hydrogen from Water Electrolysis: The Catalyst and System Efficiency

“…The energy efficiency reaches more than 86%, and the highest energy efficiency reached is 95%, which shows the feasibility of the system. According to literature reports, the energy consumption of CO 2 separation is 3.5–4.3 GJ/t, , and its average value is 3.9 GJ/t in simulation calculations. Figure shows the comparison of energy consumption of methanation between direct biogas feed and CO 2 separated from the biogas feed.…”

Efficient and Reversible Capture of CO2 in CO2-Binding Organic Liquids Formed by 1,1,3,3-Tetramethylguanidine and Glycerol Derivatives

“…As shown in Figure , the cyclic capacity of CO 2 -BOL is more than 92% of the initial absorption after 5 cycles of absorption/desorption. It is much higher than that of the 30% MEA solution, which was only about 60% of the initial absorption . Moreover, take TMG-3AP (1:1) as an example, the recoverable performance of CO 2 -BOL was almost independent of the CO 2 partial pressure (Figure S4).…”

“…Five CO 2 absorption/desorption cycles of CO 2 -BOLs and 30% MEA at 1.0 atm. (Absorption: 313.2 K, desorption 353.2 K for CO 2 -BOLs and 363.2 K for 30% MEA.…”

“…It is much higher than that of the 30% MEA solution, which was only about 60% of the initial absorption. 43 Moreover, take TMG-3AP (1:1) as an example, the recoverable performance of CO 2 -BOL was almost independent of the CO 2 partial pressure (Figure S4).…”

Investigation of Biocatalytic Absorption and Ultrasound-Assisted Desorption Performance of CO2 Capture

“…Solvent regeneration is energetically demanding, representing about 70% to 80% of the total energy consumption [8]. The high specific heat of water increases the sensible heat, and the low boiling point of water results in vaporization during the regeneration process, leading to solvent loss [9]. This high energy demand is the driving force behind the development of new solvents with lower regeneration energy consumption.…”