Properties of aqueous amine based protic ionic liquids and its application for CO2 quick capture
Graphical abstract
Introduction
At least 97% of environmental scientists have an opinion that greenhouse gas emission (GHG) plays a key role for global climate change [1], [2]. Fuel use, food production and agriculture are all sources of GHG. According to recent report by B Jacob group, direct emission for advanced coal power plants contribute CO2 850–1000 g/kWh, NOx 0.5–1.5 g/kWh, SO2 0.5–0.7 g/kWh and PM2.5 g/kWh [3]. Hence, it is an urgent to find more efficient methods to reduce those GHG, especially CO2 considering its huge emission. Currently, aqueous amines are common commercial absorbents to be widely used to remove CO2 [4], [5], [6], [7], [8], [9]. Primary amines often have more special affinity to CO2 because they have higher basicity relative to secondary amines and tertiary amines. The binding energy of CO2 to different amines decreases in the order: primary amine > secondary amine > tertiary amine studied by P Ratnasamy [10]. It is clear that primary amine may have more superiority than secondary amine and tertiary amine. Ethanolamine (MEA) is the benchmark absorbent of primary amine because of its outstanding advantages such as low price, high absorption capacity of CO2 and higher reaction speed [11], [12], [13]. In general, CO2 could direct react with MEA to form the carbamate complex and hardly to be recovered for next CO2 capture cycle comparing with some recyclable absorbents. However, some shortcomings such as easy degradation, volatile organic compound and corrosion activity, should overcome [14].
Ionic liquids (ILs) which is a type of room temperature melt point salts with designable cations and anions are recognized as an kind of environmental friendly absorbent of CO2 for some highlighted properties, for instance, neglected vapor pressure, stable chemical property, tunable structures et al [15], [16]. Protic ionic liquids (PILs) are formed through the transfer of a proton from a BrØnsted acid to a BrØnsted base [17], [18]. Compared with pure amines, PILs have a proton to form hydrogen bond avoiding non-negligible vapor pressure and decomposition of absorbent. If PILs are synthesized by stronger acid and/or stronger base in the case of aqueous solutions, the proton-transfer process can be improved [19], [20]. D R MacFarlane et al. studied a series of diamino protic ILs, among that DEEDAH-formate and DMEDAH-acetate + water (1:1 by mol) could absorb 0.50 mol CO2 of per mol ILs [21], [22]. Y T Wu group found that cyano-containing PILs showed highly selective absorption of SO2 from CO2, ethoxyacetate anions would play role to capture SO2 rather than tertiary amine cations [23]. Inspired by those pioneering works, we design three different amine-containing ILs solutions which may combine virtue of amine cations and ethoxyacetate anions. These PILs solutions are assumed to be excellent absorbents for CO2 capture. The structures of three kinds of pure amine-containing PILs are listed in Scheme 1. It is found that pure [DMAPAH][EOAc] and [DEEDAH][EOAc] are solid at room temperature because of stronger ion-ion interactions. The mass fractions of water in those pure PILs are all no more than 200 ppm. 10% (wt) water is added into those pure PILs to get PILs solution. To prove the potential application of 90% PILs solution uptake CO2, some properties are determined including density, viscosity and solubility of CO2.
Section snippets
Materials and apparatus
CO2 (99.99 mol%) were supplied from Nanjing Tianze Gas Co. (Nanjing, China). 3-(dimethylamino)-1-propylamine (AR grade, 99.5 wt%), N,N-diethylethylenediamine (AR grade, 99.5 wt%), N,N-dimethylethylenediamine, Ethanol amine (AR grade, 99 wt%) and ethoxyacetic acid (AR grade, 99.5 wt%) were purchased from Aladdin Chemical Reagent Co., and used without further purification.
The FTIR spectra were conducted on Bruker Tensor 27 FTIR instrument. 1H and 13C NMR spectra were measured on Bruker AVANCF
Density of PILs
The density is one of basic physical properties to calculate gas solubility based on Eq. (2) for the process of absorption. Trends of densities of the three 90% PILs are measured in the temperature range of 303.2 K–333.2 K. The Eq. (2) where a and b are adjustable parameters was applied to linearly correlate between the temperature T and density ρ. The results are graphically shown in Fig. 1 and the related model parameters are shown in Table 1. The density data of three ILs could be fitted
Conclusion
In summary, [DMAPAH][EOAc], [DEEDAH][EOAc] and [DMEDAH][EOAc] were synthesized through one-step procedure and 10% water were added in the pure PILs to get high contents of PILs solution, 90% [DMAPAH][EOAc], 90% [DEEDAH][EOAc] and 90% [DMEDAH][EOAc]. The physical properties including density and viscosity were measured. To compare with pure amines for CO2 uptake, the solubility of CO2 in three PILs solutions was systematically determined from 303.2 K to 333.2 K under the pressure of 1.2 bar. The
CRediT authorship contribution statement
Liang Wei: Investigation, Writing - original draft. Ruifeng Guo: Investigation. Yunqing Tang: Data curation. Jiamin Zhu: Data curation. Meiyang Liu: Formal analysis. Jianqiu Chen: Conceptualization. Yun Xu: Conceptualization, Writing - review & editing, Supervision.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
This work was supported by National Natural Science Foundation of China (no. 21808246), National Innovation and Entrepreneurship Training Program for Undergraduate (201910316235), Fundamental Research Funds for the Central Universities (no. 2632017PY01), College Students Innovation Project for the R&D of Novel Drugs (no. J1310032) and Jiangsu Overseas Visiting Scholar Program for University Prominent Young & Middle-aged Teachers and Presidents.
References (49)
- et al.
How will Canada’s greenhouse gas emissions change by 2050? A disaggregated analysis of past and future greenhouse gas emissions using bottom-up energy modelling and Sankey diagrams
Appl. Energy
(2018) - et al.
The role of natural gas and its infrastructure in mitigating greenhouse gas emissions, improving regional air quality, and renewable resource integration
Prog. Energy Combust. Sci.
(2018) - et al.
Aqueous amine solution characterization for post-combustion CO2 capture process
Appl. Energy
(2017) - et al.
Thermal stability and corrosion of tertiary amines in aqueous amine and amine-glycol-water solutions for combined acid gas and water removal
J Nat. Gas Sci. Eng.
(2019) - et al.
Selective absorption of H2S from gas streams containing H2S and CO2 into aqueous solutions of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol
Sep. Purif. Technol.
(2004) - et al.
Sites for CO2 activation over amine-functionalized mesoporous Ti (Al)-SBA-15 catalysts
Micropor. Mesopor. Mater.
(2006) - et al.
Comparative study of CO2 absorption in packed column using imidazolium based ionic liquids and MEA solution
Sep. Purif. Technol.
(2015) - et al.
Supported ionic liquid membranes (SILMs) as a contactor for selective absorption of CO2/O2 by aqueous monoethanolamine (MEA)
Sep. Purif. Technol.
(2020) The reaction of CO2 with ethanolamines
Chem. Eng. Sci.
(1979)- et al.
Corrosion and degradation in MEA based post-combustion CO2 capture
Int. J. Greenh. Gas. Con.
(2016)
Base-rich diamino protic ionic liquid mixtures for enhanced CO2 capture
Sep. Purif. Technol.
Thermophysical properties of phosphonium-based ionic liquids
Fluid. Phase Equilibr.
Densities, viscosities and derived thermophysical properties of water-saturated imidazolium-based ionic liquids
Fluid. Phase Equilibr.
CO2 capture with hybrid absorbents of low viscosity imidazolium-based ionic liquids and amine
Appl. Energy
Improved CO2 capture and separation performances of a Cr-based metal–organic framework induced by post-synthesis modification of amine groups
Polyhedron
Thermodynamic validation of double bond comprised ionic liquids for CO2 capture
J. Environ. Chem. Eng.
Concentrated aqueous solutions of protic ionic liquids as effective CO2 absorbents with high absorption capacities
J. Mol. Liq.
Low-viscous fluorine-substituted phenolic ionic liquids with high performance for capture of CO2
Chem. Eng. J.
Investigation of the absorption performance and viscosity for CO2 capture process using [Bmim][Gly] promoted MDEA (N-methyldiethanolamine) aqueous solution
Energy
Fuel use and greenhouse gas emissions of world fisheries
Nat. Clim. Change
Energy performance of stripper configurations for CO2 capture by aqueous amines
Ind. Eng. Chem. Res.
Alternative stripper configurations for CO2 capture by aqueous amines
AIChE J.
Amine scrubbing for CO2 capture
Science
Ionic liquids for clean technology
J. Chem. Tech. Biotechnol.
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