低共熔溶剂吸收二氧化硫及机理的研究

It is an important problem to absorb and separate SO2 efficiently and cleanly from the flue gas. The traditional lime-limestone process has inherent weak points such as high energy consumption and second polution. The unique properties of Deep Eutectic Solvents (DESs) provided new opportunities for the development of highly efficient gas absorption and separation thechnology. In this project, a series of DESs were synthesized in order to absorb and separate SO2. The dissolution rules of SO2 and gas mixtures containing SO2 in DESs will be studied. The matching rules and synergistic effect of the different components in the DESs will be investigated. Spectroscopy methods will be used in order to study the intermolecular interactions and micro structures of the absortion systems. The relationships between the solubilities of gases, thermodynamic properties, intermolecular interactions, and the micro structures of the solutions will also be studied. The influence of temperature, pressure, time, gas compositions, the compostions of DESs, and the structures and properties of DESs on the behaviors of gas dissolving will be researched. The key factors that influence the absorption capacity of DESs will be elucidated. The conditions of gas absortion and desorption will be optimized in order to obtain a number of DESs which can capture and separate SO2 efficiently with the aim of lying the scientific basis for developing clean and efficient SO2 absortion and separation technology.

从工业烟气中清洁高效地吸收和分离SO2进而缓解大气污染是一项重要难题。传统的石灰石石膏法存在能耗大、二次污染等严重问题。低共熔溶剂的特性为开发此类技术提供了新的机遇。本项目针对SO2吸收和分离，设计合成和筛选一系列的低共熔溶剂。研究SO2以及含有SO2的混合气体在低共熔溶剂中的溶解规律，探索低共熔溶剂中各组分间的匹配规律与协同作用。采用光谱等实验手段研究体系中的分子间相互作用和溶液的微观结构，研究气体溶解量、化学热力学性质、分子间相互作用以及溶液的微观结构之间的关系。系统研究温度、压力、时间、气体组成、低共熔溶剂的组成、低共熔溶剂的结构和性质对气体溶解行为的影响规律，揭示影响低共熔溶剂吸收性能的关键因素。优化吸收和解吸条件，获得多种高效吸收和分离SO2的低共熔溶剂体系，为开发高效清洁的SO2吸收分离技术奠定科学基础。

本项目合成出了多种对于SO2具有较好吸收效果的低共熔溶剂。研究了吸收温度、SO2气体分压、水分、低共熔溶剂的组成对吸收容量的影响，考察了低共熔溶剂的组成对循环使用效果和脱附性能的影响。利用核磁、红外等分析方法，结合量子化学方法，研究了低共熔溶剂的分子间相互作用，计算了吸收焓，揭示了低共熔溶剂吸收SO2的机理。这些结果将为新型低共熔溶剂的设计以及低共熔溶剂在吸收SO2的应用奠定基础。此外，我们合成出了基于非质子有机物丁二腈的新型低共熔溶剂，并且制备出了对CO2具有较高吸收容量的阴离子功能化低共熔溶剂。