State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Department of Chemistry, Taiyuan Normal University, Taiyuan, 030031, China.
J Hazard Mater. 2017 Feb 15;324(Pt B):457-463. doi: 10.1016/j.jhazmat.2016.11.012. Epub 2016 Nov 4.
Sulfur dioxide (SO) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and l-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO efficiently. SO absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332mol SO/mol HBA for Bet+EG DES and 0.820mol SO/mol HBA for L-car+EG DES at 40°C with a SO partial pressure of 0.02atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO by DESs was studied by FT-IR, H NMR and C NMR spectra. It was found that there are strong acid-base interactions between SO and -COO on HBA.
二氧化硫（SO）是化石燃料燃烧产生的主要空气污染物之一。在这项工作中，我们发现环境友好的溶剂，深共晶溶剂（DESs）可以设计成具有吸收模拟烟道气中低分压 SO 的功能。两种基于甜菜碱（Bet）和左旋肉碱（L-car）作为氢键受体（HBA）和乙二醇（EG）作为氢键供体（HBD）的可生物降解功能 DESs 是用 HBA 与 HBD 的摩尔比为 1:3 至 1:5 制备的，并研究了它们在不同温度下吸收不同分压的 SO 的情况。结果表明，两种 DESs 都能有效地吸收低分压 SO。HBA/HBD 摩尔比为 1:3 的 DESs 在 40°C 和 SO 分压为 0.02atm 时，Bet+EG DES 的 SO 吸收容量为 0.332mol SO/mol HBA，L-car+EG DES 的 SO 吸收容量为 0.820mol SO/mol HBA。此外，再生实验表明，DESs 的吸收容量在五次吸收和解吸循环后没有变化。进一步通过 FT-IR、H NMR 和 C NMR 谱研究了 DESs 吸收 SO 的机理。结果发现，SO 与 HBA 上的-COO 之间存在强酸碱相互作用。
