Adsorption processes in highly microporous nanostructures for advanced energy and environmental technologies

高微孔吸附剂在开发更绿色、更高效的能源和环境技术方面发挥着关键作用。它们可用作变压吸附(PSA)系统中的活化剂，用于净化沼气以改善与天然气基础设施和能源技术的兼容性，从碳氢化合物流中提取氢气以提高石油工业气体重整技术的能效，或从废物中提取氢气用于零直接排放发电。PSA还可用于去除温室气体和流出气中的污染物，以进行封存或处置。微孔吸附剂还可用于甲烷和氢气等气体燃料在高能密度下的可逆、低压和安全存储。 基于吸附的应用设计需要能够准确预测气体在由高度微孔颗粒制成的多孔粉中运动时的复杂流体力学现象，同时经历与温度非线性相关的吸附过程并产生显著的热效应。从微观到宏观的综合多尺度方法原则上可以根据目标操作条件(压力、温度、流动条件)、具体应用和待处理气体来确定最佳的微观和宏观吸附性能。 该建议的目标是：(1)开发一种多尺度综合方法，该方法将使用统计物理来连接吸附过程的微观计算，以根据已知的纳米结构和相互作用来预测新的纳米结构在广泛的热力学条件下的吸附等温线，开发具有最少物理意义的可与微观性质相关的可调参数的吸附等温线模型(吸附状态方程)，以及基于等温线模型的系统(气体储存和净化/分离)的计算机流体力学(CFD)模拟，以确定特定应用的最佳操作条件、热管理和几何形状；(2)基于CFD系统模拟，通过优化模型等温线来确定最佳的吸附性能范围，以指导新的多孔纳米结构的开发(逆向工程)；(3)加深对极端热力学条件(与氢的吸附储存相关)下超临界状态下的物理吸附(T&gt；TC)的理解，特别是超临界状态下吸附密度的饱和极限。

Highly microporous adsorbents are playing a key role in the development of greener and more efficient energy and environmental technologies. They can be used as active agents in pressure swing adsorption (PSA) systems to purify biogas to improve compatibility with natural gas infrastructure and energy technologies, to extract hydrogen from hydrocarbon streams to improve the energy efficiency of gas reforming technologies for the oil industry or to extract hydrogen from waste for zero direct emission electric power generation. PSA can also be used to remove greenhouse gases and contaminants from effluent gases for sequestration or disposal. Microporous adsorbents can also be used for the reversible low-pressure and safe storage of gaseous fuels such as methane and hydrogen at high energy densities. The design of adsorption-based applications requires the ability to accurately predict the complex fluid mechanics phenomena associated with the kinetics of gases moving through porous powders made of highly microporous pellets, while undergoing adsorption processes that depend non-linearly on temperature and that generate significant thermal effects. An integrated multi-scale approach, from the microscopic to the macroscopic, can in principle determine optimal microscopic and macroscopic properties of adsorbents as a function of target operating conditions (pressure, temperature, flow conditions), specific to the application, and of the gases to be processed. The objectives of this proposals are (1) to develop a multiscale integrated approach that will bridge microscopic calculations of the adsorption process using statistical physics to anticipate the adsorption isotherms of new nanostructures over wide ranges of thermodynamic conditions from known nanostructures and interactions, the development of adsorption isotherm models (equations of state of adsorption) characterized by the smallest number of physically meaningful adjustable parameters that can be correlated to microscopic properties, and computer fluid mechanics (CFD) simulations of systems (gas storage and purification/separation) based on the isotherm models to determine application-specific optimal operating conditions, thermal management and geometries; (2) to determine optimal adsorbent properties ranges based on CFD system simulations by optimizing model isotherms to guide the development of new porous nanostructures (reverse engineering) and (3) to further the understanding of physisorption in the supercritical state (T>Tc) under extreme thermodynamic conditions (relevant to adsorption storage of hydrogen), notably the saturation limit of the adsorbed density in the supercritical state.