乙烯-乙烷吸附反转MOFs吸附剂的构筑策略及性能研究

Conventional adsorbent displaying preferential adsorption of ethylene during ethylene/ethane separation process. While there is an urgent need for ethane-selective adsorbent to separate the ethane impurity (< 10%) during the coal (methanol) to olefin (CTO and MTO) process. Therefore, some new adsorbents with reversed of ethylene/ethane adsorption ability are caused much attentions. In this project, we will introduce a strategy to achieving the reversal of ethylene/ethane adsorption in metal-organic frameworks (MOFs), which modification of open metal sites to block the π-π interactions between ethylene and MOFs, in the meantime construction ethane binding sites to increase the ethane adsorption. This work will opens a new avenue for efficient ethylene/ethane separation, provide theoretical and technical support for efficient ethylene/ethane separation in the CTO and MTO process, and expand the application of MOFs materials for gas adsorption and separation.

常规吸附剂分离乙烯/乙烷，都是优先吸附乙烯，而在煤（甲醇）制乙烯生产等过程中，迫切需要的是优先吸附乙烷（＜10%）除杂，因此，乙烯-乙烷吸附反转新型吸附剂引起关注。本项目拟通过对金属有机骨架材料（MOFs）的不饱和金属空位进行修饰，阻挡其与乙烯的π键相互作用，同时构建乙烷吸附位，提高其对于乙烷的吸附能力，实现乙烯-乙烷吸附反转的突破，为乙烯/乙烷的高效分离开辟一条新途径，为煤（甲醇）制乙烯工艺中乙烯/乙烷的高效分离提供理论支持和技术支撑，拓展MOFs材料在气体吸附分离方面的应用。

本项目以创制高选择性乙烷吸附剂为目标，通过对金属有机骨架（MOF）材料的不饱和金属空位进行修饰，实现了乙烯-乙烷吸附反转的突破。并围绕新型多孔材料（金属有机骨架和共价有机框架）的设计构筑与性能优化，对吸附剂孔尺寸和孔环境对乙烷吸附选择性及分离性能的影响规律进行了系统研究：1. 创制了系列具有不同配位环境，不饱和金属空位的MOF材料，测试了其对于乙烯、乙烷的吸附分离性能，总结得到乙烯、乙烷吸附性能与MOF材料结构间构效关系；2. 对具有不饱和金属空位的MOF进行空位修饰，系统调变材料的乙烷选择性。3. 设计并搭建了乙烷/乙烯分离提纯装置，详细考察了动态条件下MOF材料对于乙烷/乙烯混合物的分离性能以及循环寿命。最终研制出系列乙烷优先吸附的新型MOF吸附剂，系统建立了乙烷选择性MOF材料构建与性能调控的科学认知。