Characteristics of Potassium Prolinate + Water + Ethanol Solution as a Phase Changing Absorbent for CO₂ Capture

Abstract

Potassium prolinate + water + ethanol (ProK/W/Eth) solution has potential use as a liquid-to-solid phase-changing absorbent for energyefficient CO 2 capture process. In this study, the equilibrium solubility of CO 2 in ProK/W/Eth solutions was measured in a stirred equilibrium cell at a temperature range from 293 to 343 K and CO 2 partial pressures up to 200 kPa. Density and viscosity were also measured at temperatures from 293 to 333 K and ProK molality up to 6.09 mol•kg −1 ethanol. Moreover, the CO 2 loading and cyclic capacity were compared with aqueous monoethanolamine (MEA) and aqueous ProK solution. The solubility data were well-represented using a Soft model with AAD within 8.0%. The data of density and viscosity were also correlated with empirical models. The predicted results matched well the experimental data with AAD within 0.37% for density and 1.38% for viscosity.

Kinetics of Carbon Dioxide Absorption into Water-Lean Potassium Prolinate/Ethylene Glycol Solutions

“…= Sh R e S c 0.073 0.74 0.59 (14) It can be seen from the graphic comparison in Figure 2, the calculated values from the correlation matched well with the experimental data with an AAD within 2.5%. The correlation was used for the calculation of physical mass transfer coefficient, k L , in the following kinetics study.…”

“…Compared with MEA, potassium prolinate (ProK) is of great interest as an absorbent because of fast kinetics, low volatility, and good resistance to oxidative degradation. − Besides the aqueous ProK, ProK-based water-lean solutions, such as ProK/ethanol/water and ProK/ethylene glycol (EG)/water, have been recently proposed for energy-efficient CO 2 capture. , ProK/water/ethanol solution showed a fast absorption rate of CO 2 and can undergo a liquid-to-solid phase change process during CO 2 absorption. About 55–60% of the total CO 2 captured was enriched in the solid phase, which suggests the potential to lower the energy consumption. ,, However, associated issues such as ethanol vapor loss and complicated solid-phase transfer process, need to be considered in future studies. ProK/EG/water solution has also shown advantages of high physical solubility of CO 2 and low solvent vapor pressure .…”

“…About 55−60% of the total CO 2 captured was enriched in the solid phase, which suggests the potential to lower the energy consumption. 12,14,15 However, associated issues such as ethanol vapor loss and complicated solid-phase transfer process, need to be considered in future studies. ProK/EG/water solution has also shown advantages of high physical solubility of CO 2 and low solvent vapor pressure.…”

A Comparative Study of Aqueous Potassium Lysinate and Aqueous Monoethanolamine for Postcombustion CO2 Capture

“…A schematic diagram of the experimental setup was presented in Figure . The method and procedure was similar to that for CO 2 solubility measurement described in our previous work. , The setup consists of a vessel ( V v , 2.15 L) for storing the CO 2 gas and a reactor ( V R , 0.61 L) with pressure transducers (MIK-P300, 0–6 bar, MEACON China; GS4200-USB,0–6 bar, ESI). The temperatures ( T V and T R ) were recorded by PT-100 thermocouples (WZP-293) and a recorder (MIK200D) from MEACON China.…”

CO2 Capture by Water-Lean Amino Acid Salts: Absorption Performance and Mechanism

“…Recently, aqueous amino acid salts are of great interest as alternative absorbent for CO 2 capture due to their intrinsic basicity, high capacity and kinetics, good resistance to thermal and oxidative degradation, biodegradability, and commercial availability. ,− A water-lean AAS system might be one of the possible methods to reduce energy consumption in close to viable capture costs for postcombustion CO 2 capture. In our previous work, we have proposed potassium prolinate (ProK)/​ethanol/​water solution as a water-lean absorbent. , This solvent can undergo a liquid-to-solid phase change during CO 2 absorption. Low-temperature regeneration for solid phase enriched in about 50% of the total CO 2 captured may significantly lower the energy consumption.…”