In this work, the blends of 1-hydroxyethyl-3-methylimidazolium glycine ([C 2 OHmim][Gly]) synthesized by our laboratory and N-methyldiethanolamine (MDEA) in aqueous solution were prepared for CO 2 capture, and the maximum absorption performance of the blends was obtained at the mole ratio of 8:2 of MDEA/[C 2 OHmim][Gly] with a total concentration of 1.0 mol L −1 . CO 2 loading of the blended absorbent was less adversely influenced by the temperature and O 2 concentration than that of MDEA aqueous, and it had a good performance in regeneration ability. The reaction mechanism of the CO 2 absorption in MDEA/[C 2 OHmim][Gly] was investigated by 13 C nuclear magnetic resonance. CO 2 first reacted with [C 2 OHmim][Gly] to form carbamate, and then carbamate promoted the reaction between CO 2 and MDEA, which could be described as a shuttle mechanism. The kinetics of CO 2 absorption was investigated in a double stirred-cell absorber at different temperatures, and some important kinetic parameters were obtained, such as the reaction rate constant (k 2 ) and the overall rate constant (k ov ). Experimental results indicated that the addition of [C 2 OHmim][Gly] enhanced CO 2 absorption of MDEA under low CO 2 partial pressure, which could improve the application of MDEA in industry.

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The chemical absorption-biological reduction (CABR) integrated process is regarded as a promising technology for NOx removal from flue gas. To advance the scale-up of the CABR process, a mathematic model based on mass transfer with reaction in the gas, liquid, and biofilm was developed to simulate and predict the NOx removal by the CABR system in a biotrickling filter. The developed model was validated by the experimental results and subsequently was used to predict the system performance under different operating conditions, such as NO and O2 concentration and gas and liquid flow rate. NO distribution in the gas phase along the biotrickling filter was also modeled and predicted. On the basis of the modeling results, the liquid flow rate and total iron concentration were optimized to achieve >90% NO removal efficiency. Furthermore, sensitivity analysis of the model revealed that the performance of the CABR process was controlled by the bioreduction activity of Fe(III)EDTA. This work will provide the guideline for the design and operation of the CABR process in the industrial application.

An amine-based biphasic solvent is promising to cut down the energy penalty of CO2 capture. However, the high viscosity of the CO2-enriched solvent retards its industrial application. This work proposed a novel dual-stage phase separation process using a triethylenetetramine and 2-(diethylamino)­ethanol blend as a biphasic solvent, which separates a certain proportion of CO2-enriched phase during CO2 absorption to reduce its viscosity. Experimental results showed that the proposed dual-stage phase separation process improved the phase separation behavior and effectively enhanced the absorption rate by 49% at 50 °C, when 50 vol % CO2-enriched phase was separated at 0.3 mol mol–1. Kinetic analysis showed that the absorption rate was mainly controlled by liquid-side mass transfer. The regeneration heat of the dual-stage phase separation process cut down the energy penalty by 33% compared with the monoethanolamine-based process. Compared with the conventional biphasic solvent-based process, the heat duty was further declined by 8%. The 1H nuclear magnetic resonance analysis showed that the dual-stage phase separation process could effectively control the generation of absorption products and intensify the interphase migration of tertiary amines.