Investigation on the Phase-Change Absorbent System MEA + Solvent A (SA) + H₂O Used for the CO₂ Capture from Flue Gas

Abstract

Amine-based CO 2 postcombustion capture is a commercialized technology for recovery CO 2 from flue gas, and the energy consumption is concentrated in the regenerative stage. The phase-change solvent system, monoethanolamine (MEA, absorbent) + solvent A (SA, solvent) + water (solvent), was investigated on the performances of CO 2 absorption and desorption. CO 2 -rich solvent can be continuously separated for the feeding flow of the regeneration tower; thereby, it significantly reduces the energy of regeneration. The results show that the solvent with suitable composition can easily separate the CO 2 -rich phase from the solvent, and the CO 2 -rich phase accounts for more than 98% of the total CO 2 . At 293−333 K, the temperature has no significant effect on the absorption rate and phase equilibrium. The estimation of energy consumption shows that the reboiler work can be reduced by 43.6% compared with that using 20 wt % MEA aqueous solution.

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

“…The current research studies on a CO 2 capture solvent mainly focus on developing an absorbent with a high absorption rate, large capacity, low specific heat capacity, and low saturated vapor pressure. For example, ionic liquids possess large CO 2 absorption capacity, but the high cost and high viscosity hinder their industrial applications. , Phase-change absorbents can automatically separate a CO 2 -rich-phase from a poor-phase solution; the energy consumption can be reduced by cutting the amount of the absorbent loaded in a regenerator. , However, phase changeable solvents are still expensive, and the CO 2 -rich liquid phase generally possesses high viscosity, which is not conducive to desorption . Nonaqueous solutions, especially the organic alcohol solvents [e.g., triethylene glycol, propylene glycol, ethylene glycol, and poly­(ethylene glycol) (PEG)], are considered as one class of the promising solvents.…”

“…11,12 Phasechange absorbents can automatically separate a CO 2 -rich-phase from a poor-phase solution; the energy consumption can be reduced by cutting the amount of the absorbent loaded in a regenerator. 13,14 However, phase changeable solvents are still expensive, and the CO 2 -rich liquid phase generally possesses high viscosity, which is not conducive to desorption. 15 Nonaqueous solutions, especially the organic alcohol solvents [e.g., triethylene glycol, propylene glycol, ethylene glycol, and poly(ethylene glycol) (PEG)], are considered as one class of the promising solvents.…”

An Efficient Solid–Liquid Biphasic Solvent for CO2 Capture: Crystalline Powder Product and Low Heat Duty

“…3−5 To develop energy-saving and feasible systems has posed one of the main challenges in this field. 6,7 Recently, the biphasic solvent, which features phase changing behavior, looks forward to being an alternative for CO 2 capture due to its huge energy-saving potential. The existing biphasic solvents could turn into the liquid−liquid phase or solid−liquid phase tuning by the CO 2 loading and temperatures.…”

“…Carbon dioxide (CO 2 ) emissions have generated many negative climatic effects. , Carbon capture, utilization, and sequestration (CCUS) is considered to be the most effective strategy to reduce the emission of CO 2 . As a commercially utilized solvent, the traditional monoethanolamine (MEA)-based absorbent requires high energy consumption (3.6–4.0 GJ t –1 CO 2 ) for regeneration due to the large energy penalty for the solvent regeneration. − To develop energy-saving and feasible systems has posed one of the main challenges in this field. , …”

Mechanism of CO<sub>2</sub> capture into amino-azolyl dual-functionalized ionic liquid biphasic solvent

“…Wang等 [13] 开发了单乙醇胺/正丙醇相变吸收 剂, 其再生能量降低了39.85%, 循环容量从1.01 mol CO 2 /kg absorbent增加到2.51 mol/kg. Zhu等 [14] 开发的 MEA+SA+H 2 O吸收剂, 与30 wt%单乙醇胺相比, 其再 生时所需要的能量减少了43.6%. Shen等 [15] 将脯氨酸 钾 与 乙 醇 混 合 形 成 分 相 吸 收 剂 , 其 吸 收 容 量 为 0.55 mol CO 2 /kg absorbent, 在120℃加热且0.2 L/min N 2 吹扫下再生效率高达90.9%.…”