低氢富CO2含杂石化尾气双膜-电化学氢泵原位分离常压加氢资源化

Hydrogenation is one of the important ways to the utilization of CO2. It usually performs at high pressure and temperature with reactants of high purity due to high thermaldynamical stability of CO2. There are huge amount of CO2 enriched refinery gases, however, could not be separated due to the presence of impurities, such as CH4 and CO. Most of them are burned just as fuel because of the high energy intensity and complicated equipment. Dual membrane-electrochemical hydrogen pump (DM-EHP) insitu separation-hydrogenation is proposed in this project to synergistically improve efficiency of CO2 utilization. Loading two kinds of membranes in the dual membrane module, which selectively permeate CO2 and H2 respectively and remove impurities from retentate. The concentrated CO2 and H2 are send to the cathode and anode of the electrochemical hydrogen pump. H2 dissociates controllable into protons by the anode catalyst, transports to the cathode through proton exchange membrane to form insitu adsorbed hydrogen atom on the cathode catalyst layer, and then hydrogenates with adsorbed CO2 at ambient pressure and temperature..There are several keys to this project, such as separation-hydrogenation synergetic effects between DM and EHP, multi-components and multi-sizes catalytic mechanism of the three-dimensional electrode and optimization of the dual membrane module. As solutions, N hybrid multi-size porous metal-carbon composite electrode, dynamic model of the EHP, accurate math model of the DM and coupling optimization method will be investigated and established in this project. As results, transport and adsorption of reactants of the EHP will be matched and the conversion of CO2 to alcohol and carboxylic acid based fuels will be reached.

加氢是CO2其资源化的重要途径，但CO2热力学稳定，需高纯度的原料和高温高压下的反应。大量富含CO2的石化尾气，因含CH4和CO等杂质，现有分离方法高能耗、设备复杂，难以资源化，低浓度氢也随之浪费。本项目提出双膜-电化学氢泵协同增效原位分离-加氢，膜分离器内填装两种选择透过性膜，双向富集克服了商业化膜性能不高的问题；纯化后的CO2和H2分别作电化学氢泵的阴、阳极进料，H2在阳极可控解离成H+，传导至阴极形成高活性的原位吸附氢，对CO2实现常温、常压下的加氢。针对双膜-电化学氢泵高效原位分离加氢的协同作用、立体化电极的多组分、多尺度催化机理和双膜优化设计等关键科学问题，拟设计制备N掺杂多级孔金属-碳膜复合立体化电极、电化学氢泵高效原位分离加氢的协同作用和耦合动力学模型，建立双膜分离器的准确数学模型和耦合优化方法，解决氢泵反应物匹配传输等问题，实现低氢富CO2含杂尾气向酸、醇基燃料的资源转化。

加氢是CO2资源化的重要途径，本项目提出双膜分离-电化学氢泵原位分离-加氢协同增效，建立创新性的分离、反应过程强化理论和方法，解决低氢富CO2石化尾气难以资源化的碳中和关键问题。双膜分离器内填装两种选择透过性膜双向富集，克服商业化膜性能不高问题；电化学氢泵中H2可控解离形成高活性原位吸附氢，常温常压实现CO2加氢。项目提出电化学氢泵关键材料及过程强化系列方法，设计质子交换膜拓扑结构和分子结构，提出原位生长梯度多孔复合膜、电纺纤维沿膜厚直通取向等拓扑结构，以及3D-氢键网络等功能主/侧链化学结构调控微相分离；设计高效复合催化电极，调控催化配位环境构筑系列原子级分散活性中心、相转化设计N掺杂多级孔碳膜三相界面和催化活性、调控吸附氢浓度消除产物抑制强化电化学氢泵传质和反应。提出双膜分离器关键材料及过程强化系列方法，构建分离膜的低阻力超薄无缺陷分离功能层；提出双膜组件非理想有限差分数学模型，建立双膜分离器实验构效，强化双向富集传质；实现膜回收装置的模拟优化。提出双膜分离-电化学氢泵耦合新工艺，建立电化学氢泵反应器的动力学传质模型，将电化学氢泵反应器和双膜分离器嵌入HYSYS流程模拟软件，优化双膜分离-电化学氢泵耦合工艺流程，实现CO2的高效分离和资源化，CO2转化率达到86.69 %，甲酸电流效率最高为81.4 %。研究成果具有自主知识产权，有助于建立我国在CO2高效资源化领域的领先地位，满足我国节能减排、碳资源循环利用重大需求。.发表高水平SCI学术论文65 篇，授权PCT专利2项，授权/申请国家发明专利 33/41 项，举办关于相关领域的学术会议 12 次，参加国际/国内学术会议43/45 人次，开展国际交流互访26 人次，培养博/硕士研究生 11/19名，培养青年长江2人，青千1人，获批2021年国家自然科学基金委创新研究群体，获得国家科技进步二等奖，圆满完成项目的研究目标。