State-of-the-art of CO₂ capture with amino acid salt solutions

Abstract

The emission of large amounts of CO2 into the atmosphere is believed to be a major reason behind climate change, which has led to increased demand for CO2 capture. Postcombustion CO2 capture with chemical solvent is considered one of the most important technologies in order to reduce CO2 emission. Amino acid salt solutions have attracted special attention in recent years due to their excellent physicochemical properties, e.g., low volatility, less toxicity, and high oxidative stability, as well as capture performance comparable with conventional amines. In this study, physicochemical properties of 20 amino acids are reported and their CO2 absorption performance discussed. The topics covered in this review include the most relevant properties of amino acids including CO2 loading capacity, cyclic capacity, equilibrium constant, density, viscosity, dissociation constant, CO2 solubility, CO2 diffusivity, reaction kinetic between CO2 and amino acid salts, reaction rate constant, surface tension, heat of CO2 absorption, precipitation, toxicity, solvent degradation, and corrosion rate. This review provides the most recent information available in the literature on the potential of using amino acid salts as a solvent for CO2 capture which can help improve the performance of the CO2 capture process from flue gas streams.

New Solvents for CO2 and H2S Removal from Gaseous Streams

“…CO 2 removal is typically much more studied, considering the wide variety of applications (natural gas, flue gas, syngas and biogas). Several reviews have been published in the literature with a specific focus each of the solvent categories: water-lean solvents [23][24][25][26], biphasic solvents [27][28][29] and green solvents [30,31]. Similar works considering H 2 S are less diffuse.…”

“…These formulations allow for obtaining a good tradeoff between viscosity and absorption capacity (i.e., the 30 wt.% 1-(3-aminopropyl)-3-(2-aminoethyl)imidazolium alaninate ([Apaeim][ala]) solution [95]), but at the same time they exploit the advantages of solid-state sorbents, such as lower regeneration energy and temperature and negligible solvent losses caused by evaporation [123]. The crystallization of the amino acid salts is expected to decrease their concentration in the solution, which leads to the formation of more products that turns out in a higher CO 2 loading [27]. Furthermore, the precipitation of carbonate allows for easy separation and regeneration of the CO 2 -loaded solvent.…”

Review of carbon capture absorbents for CO2utilization

“…88 Amino acid solutions have the flexibility to opt for both utilization with or without undergoing a desorption process due to their post-CO 2 absorption products. 159,160 However, opting for a desorption process might not be preferable for amino acid salts as its energy-intensive desorption process is a concern for large-scale applications. 160,161 Therefore, direct utilization of CO 2 is more feasible for amino acid salts.…”

Carbon Dioxide Capture Chemistry of Amino Acid Functionalized Metal-Organic Frameworks in Humid Flue Gas

“…1,2 Although aqueous amine solutions are currently being used to capture CO2, they require significant energy input because of the high heat capacity of water and suffer from loss of amines. [3][4][5][6] Porous solid-state materials are being studied for their potential in offering a platform for mounting amines and foregoing the heat requirement of aqueous solutions. [7][8][9] In this regard, materials such as carbon, 7,10 zeolites, 11 silica, [12][13][14][15] resins, 16,17 covalent organic frameworks, 18 and metal-organic frameworks (MOFs), [19][20][21][22][23] are being investigated [as summarized in Table 1, see Table S1 in the Supporting Information (SI) for more detailed comparison].…”