氟/硅功能化的低粘度、高容量CO2吸收剂的结构设计和捕集性能研究

CO2 is being considered to pay most of the responsibility for greenhouse effect, hence great efforts are constantly devoted to the exploration of efficient process for CO2 capture, which reveals particularly effective for temporarily preserving huge volumes of CO2 emission, and at the same time, providing material basis for CO2 transformation. Liquid type alkaline absorbents have been proved to be prominent across field of academic research and industrial application, however, the intrinsic nature of liquid viscosity causes the mass transfer resistance, thereby being one of the major obstacles for pursuing high absorption rate and capacity as well as low energy consumption during the desorption process. Consequently, the improvement for alternative approaches with low viscosity through molecular modification becomes an urgent and challenging subject. The present project is aiming at developing new liquid systems with low viscosity for CO2 capture by the introduction of fluoro or silyl group to the molecular structure of the absorbents (ethanolamines, alcohols and ionic liquids), which could significantly enhance mass transfer during the reaction, rendering high absorption rate and capacity with less energy input required by the capture and desorption sequence. Simultaneously, the investigation on the influence of viscosity and capacity by structure of the introduced fluoro or silyl substituents will be carried out, the thermodynamics and kinetics of the capture process should be systematically revealed as well, and detailed mechanism concerning viscosity reduction intents to be interpreted at molecular level by DFT calculations, which overall could provide theoretical basis and scientific proof for further optimization of the existing CO2 capture protocols as well as the establishment of new strategies.

二氧化碳过量排放所产生的“温室效应”是全球关注的重大环境问题，探索高效捕集技术既能推动二氧化碳减排，又成为其资源化利用的基础。碱性液体吸收剂是研究应用广泛的二氧化碳捕集策略，由液体粘度导致的传质阻力是限制其捕集速率和容量提升以及脱附能耗降低的关键因素之一，因此借助分子结构修饰以降低吸收剂粘度成为亟需解决的科学技术问题。本项目旨在将含氟或含硅基团键联到液体吸收剂（醇胺、醇和离子液体）分子结构中，设计合成低粘度二氧化碳捕集体系，通过加强反应传质以提高捕集速率和容量并削减脱附过程的传质能耗。项目拟研究含氟或含硅功能基结构与吸收剂粘度及捕集性能的关系，阐释捕集和脱附过程的热力学和动力学规律，并借助量化计算从分子层面揭示粘度降低机理，为现有二氧化碳捕集体系的优化和新策略的建立提供理论基础和科学依据。