A series of novel dual-functionalized ionic liquids (FILs) with the combinations of diethylenetriamine cation ([DETAH]+) and aprotic heterocyclic anion (AHA) are explored for efficient and reversible CO2 capture, which was distinguished from the traditional strategy by increasing the amino group number of ionic liquids. The structural features and the interactions between ions and CO2 were performed under the DFT method, at the B3LYP/6-311++G** level. The CO2 absorption loadings of [DETAH]­[Im], [DETAH]­[Py], and [DETAH]­[Tz] were 11.91, 11.36, and 10.10 mol CO2/ kg IL, respectively. After the fifth cycle, their regeneration efficiencies still kept above 90%. Based on the calculation and 13C NMR results, the reaction mechanisms of CO2 capture into [DETAH]­[AHA] solutions were clarified. The amino groups of [DETAH]+ reacted with CO2 to produce [DETAH]+-carbamates, which guaranteed the high absorption rate. Meanwhile, [AHA]− could also equimolecularly react with CO2 to form carbamate, which subsequently hydrolyzes into HCO3 –/CO3 2–. Notably, the [AHA]− was protonated during the CO2 absorption process, and [AHA]-H could react with [DETAH]+-carbamates to produce [DETAH]+, which helped to recycle the active components of the absorbent and further increased the CO2 capacity and regenerability of the absorbent. The novel dual FILs present as an efficient candidate for CO2 capture.

In the production of soy sauce-aroma type baijiu (SSAB), the quality of base liquor significantly affects the finished liquor’s quality. Moreover, low-quality liquor may cause health problems. The different quality grades of base liquor were analyzed to investigate the relationship between the quality and the key compounds in SSAB. In this study, samples were evaluated by the sensory and further analyzed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) coupled with electronic nose (E-nose). First, by sensory evaluation, the sauce, floral and fruity, fermented aromas and taste indicators (softness, fullness, harmony, purity and persistence) were positively correlated with the quality grade of the base liquor. The E-nose could distinguish the different quality grades of base liquor well. Second, differential compounds were identified via untargeted metabolome based on the HS-SPME-GC-MS. 16 common differential compounds were shared in the base liquor from different fermentation rounds, including 11 esters, 1 alcohol, 2 aldehydes and 2 ketones. It was found that the higher the quality grade of the base liquor, the richer the content of aromatics, alcohols, aldehydes and ketones. The principal component analysis (PCA) biplots of the differential compounds in the different quality grades of base liquor indicated that the superior-grade base liquor has a strong fruity aroma. By correlation analysis of the differential compounds and sensors responses of E-nose, furfuryl ethyl ether, butanoic acid ethyl ester, isopentyl hexanoate, nonanoic acid ethyl ester and 3-methyl-1-butanol had a significant effect on the response intensity of E-nose sensors. In the present study, the key differential compounds between the different quality grades of base liquor were identified, and the sensory differences between the base liquor were digitized.

No abstract