基于CNFs结构特性的煤气脱硫材料构筑及微波辐射耦合机制

Efficient removal of hydrogen sulfide is very important for energy technologies that using coal gas as raw materials. Dry desulfurization is being considered to be the most potential technology for coal gas desulfurization. However, there are still some problems in the desulfurization process of the sorbent. Such as micro-pore cracking, aggregation of active components and invalidation of structural performance, which lead to significant reduction of desulfurization performance and directly restrict the industrial application of the technology. In this project, metal oxide/CNFs composite desulfurization sorbent will be constructed by using the structural characteristics of carbon nanofibers (CNFs) and microwave effect, and its overall performance will being expected to be improved by optimizing the reactivity and micro-mass transfer efficiency of the desulfurization sorbent. Focusing on the formation mechanism of carrier CNFs and the growth mechanism of active components in the process of sorbent construction, the basic law of the microscopic pore construction of sorbent by electrospinning-microwave carbonization and its mechanism of regulating the reactivity of sorbent will be clarified. The dynamic function between microwave radiation, dielectric properties and microstructures of sorbent will be established to clarify the synergistic effect of carrier and active component and its coupling mechanism with microwave radiation. The desulfurization performance tests and reaction kinetics studies will be correlated to make a full understanding of the structure-activity relationship between microstructure of sorbent and its desulfurization performance. The strengthening effect and influencing mechanism of CNFs structure characteristics on the desulfurization reactivity and micro-mass transfer of sorbent will be clarified, and the performance improvement mechanism of sorbent will be also revealed. The successful implementation of this project will provide new ideas for the precise design and performance optimization of desulfurization sorbent.

硫化氢的高效脱除对以煤制气为原料的能源技术至关重要。干法脱硫被认为是最具潜力的煤气脱硫技术，但其脱硫过程中仍存在脱硫剂微观孔隙胀裂、活性组分团聚及结构性能失效等问题，导致脱硫剂性能显著降低，直接制约该技术的工业应用。本项目利用碳纳米纤维（CNFs）的结构特性及微波效应构建金属氧化物/CNFs脱硫剂，通过优化脱硫剂反应性和微观传质效率来提升其整体性能。探究脱硫剂构建过程中CNFs成型与活性组分生长机理，明确静电纺丝-微波碳化构建脱硫剂微观结构的基本规律；建立微波辐射-脱硫剂介电性质-微观结构之间的动态函数，明晰载体和活性组分的协同作用及其与微波辐射的耦合机制；关联脱硫性能测试并结合反应动力学研究，明确脱硫剂微观结构与脱硫性能的构效关系，阐明CNFs结构特性对脱硫剂脱硫活性和微观传质的强化作用和动力学影响机制，揭示脱硫剂性能提升基本原理。本项目的顺利实施将为脱硫剂精确设计和性能优化提供新思路。

高温煤气脱硫是实现煤炭清洁高效利用的关键，对于高性能脱硫剂制备及其反应机理的研究具有重要意义。本项目针对脱硫剂结构性能失效和反应效率低等问题，系统研究了金属氧化物/碳纳米纤维（CNFs）脱硫剂构筑机理和CNFs结构特性强化脱硫性能提升的基本原理，阐明了脱硫剂微观结构与性能的构效关系。通过控制纺丝电压、聚合物浓度、活性组分前驱体含量等参数，确定了静电纺丝法制备聚合物复合纳米纤维膜的最佳工艺；通过控制纤维膜微波碳化过程参数，揭示了脱硫剂制备过程中的微波效应及其与载体和活性组分的耦合机制，发现微波碳化使脱硫剂孔隙结构更丰富，而且促进了金属氧化物的成核和生长；通过控制硬模板法改性CNFs体相结构的工艺参数，探明了CNFs的结构调控机理，发现在CNFs体相中引入中空结构有利于提高活性组分负载量，有益于提高脱硫剂硫容；通过控制活性组分前驱体结构形式，探明了活性组分与载体CNFs的协同作用，与金属盐相比，ZIF-8的热分解优化了CNFs表面网格结构，实现了活性组分ZnO的高度有序分布；通过向活性组分中引入过渡金属Co，探明了活性组分组成对脱硫剂微观结构和脱硫性能的影响规律；密度泛函理论研究表明，硫化氢在ZnxCo3-xO4晶粒表面吸附的活化能更低，脱硫反应更容易进行；通过关联脱硫性能测试，发现复合金属氧化物ZnxCo3-xO4的形成有助于脱硫剂活性及稳定性的提高。本项目通过阐明CNFs结构特性与微波效应对脱硫剂反应活性的强化作用，形成了优化脱硫剂结构性能和反应传质的技术基础，为提升脱硫剂整体性能提供了理论依据和技术支撑。