烧结/硫酸化作用下的Li4SiO4吸附CO2机理与全过程数值模拟

基于Li4SiO4的高温CO2吸脱附是一种新型、高效的碳捕集技术。CO2吸附是该技术的核心过程，耦合了化学反应、结构演变和热/质传递，且烧结和硫酸化两个关键因素会改变吸附剂微观结构和反应模式，加剧吸附过程的复杂性。因此，需要在弄清烧结和硫酸化影响作用的前提下，对Li4SiO4的CO2吸附机理与全过程数值模型进行系统研究。首先，考察Li4SiO4吸附剂的烧结效应，获得其形貌/晶相实时演变，建立烧结过程晶粒/孔隙结构演变方程；其次，探究Li4SiO4的硫酸化机制，阐述其对于CO2吸附的影响规律及碳/硫的吸附竞争关系。进一步，结合惰性标记实验与量化计算揭示吸附过程中的组分传输机制，阐明Li4SiO4的CO2吸附机理，并构建耦合竞争反应、结构演变和热/质传递的全过程数值模型，实现对吸附过程的精确模拟。项目的实施将为开发以Li4SiO4为代表的高性能CO2吸附剂、优化脱碳反应体系奠定坚实的理论基础。

The high-temperature CO2 adsorption/desorption basing on Li4SiO4 is a new and efficient carbon capture technology. CO2 adsorption is the core process of the technology, which involves the coupling of chemical reaction, structure evolution, and heat/mass transfer. The two key factors, sintering and sulfation will change the microstructure and reaction mode of sorbents, increasing the complexity of the adsorption process. Therefore, it necessary to carry out systematic study on the mechanism and whole-process simulation model of CO2 adsorption by Li4SiO4 under the premise of understanding the influence of sintering and sulfation. First, we will investigate the sintering effect of Li4SiO4 sorbents, obtain their real-time evolution of morphology and crystal phase, and establish equations describing grain/pore structure evolution during sintering. Then, the mechanism of Li4SiO4 sulfation will be studied, and its effect on the CO2 adsorption and the adsorption competition of C/S will be expounded. Furthermore, we will reveal the mechanism of species transport in the adsorption process by combining the inert marker experiment and quantum chemistry calculation, explain the mechanism of CO2 adsorption by Li4SiO4, and develop a whole-process simulation model of coupling competitive reactions/structure evolution/heat and mass transfer to realize the accurate simulation on the CO2 adsorption by Li4SiO4. The implementation of this project will lay a solid theoretical foundation for the development of high-performance CO2 adsorbents represented by Li4SiO4 and the optimization of carbon capture systems.