Abstract:

Carbon dioxide emission reduction has become one of the important issues for the development of various countries. Conventional separation steps in chemical manufacturing usually come with a low second law efficiency, leading to large amounts of energy consumption as well as CO₂ emissions. By coupling separation with chemical reactions using an oxygen storage material, the chemical looping technology represents a promising approach to intensify chemical manufacturing via simplified product separation and cascade energy utilization. As a result, a significant increase in exergy efficiency can be realized. A combination of the chemical looping strategy and high throughput computation based on ab-initio materials simulation has the potential to rationalize the design of complex oxides for various applications. In this paper, three representative chemical looping processes, i.e., chemical looping air separation (CLAS), chemical looping oxidative dehydrogenation (CL-ODH), and chemical looping thermochemical energy storage (CL-TES), are used to exemplify the strategy to tailor the thermodynamic properties of complex oxides. Thermodynamic analysis showed that the desired thermodynamic properties for the oxides vary considerably depending on the target application. Therefore, a key direction for the development of the chemical looping strategy is application-specific and precision-engineering of complex oxides to push the existing boundaries for process efficiency and emission reduction.

Key words: chemical looping, complex oxides, redox, perovskites, exergy, process intensification

摘要：

CO₂减排已经成为各国发展的重要议题之一。化工产业的传统分离过程由于?效率过低，往往会导致大量的能源浪费及CO₂排放。作为一种典型的、耦合分离与反应的过程强化策略，化学链技术有利于实现产物分离、能量梯级利用，从而显著提升系统?效率。高通量计算与化学链技术的结合，可以针对不同化学反应，指导相应的化学链载氧体热力学性质的调变策略。以化学链空气分离、氧化脱氢和热化学储能三个典型过程为例，简述化学链过程中复杂载氧体热力学性质的调变策略。热力学分析表明，不同化学链流程中载氧体性质的优化方向和最优区间均存在显著差异。因此，未来化学链技术发展的重要方向之一，是针对不同的化工流程进行载氧体的精确调变，从而实现化工流程的最优化。

关键词: 化学链, 复杂氧化物, 氧化还原, 钙钛矿, ?, 过程强化