Low-carbon dispatchable power underpins a sustainable energy system, providing load balancing complementing wide-scale deployment of intermittent renewable power. In this new context, fossil fuel-fired power plants must be coupled with a post-combustion carbon capture (PCC) process capable of highly transient operation. To tackle design and operational challenges simultaneously, we have developed a computational framework that integrates process design with techno-economic assessment. The backbone of this is a high-fidelity PCC mathematical model of a pressure-vacuum swing adsorption process. We demonstrate that the cost-optimal design has limited process flexibility, challenging reactiveness to disturbances, such as those in the flue gas feed conditions. The results illustrate that flexibility can be introduced by relaxing the CO$_2$ recovery constraint on the operation, albeit at the expense of the capture efficiency of the process. We discover that adsorption-based processes can accommodate for significant flexibility and improved performance with respect to the operational constraints on CO$_2$ recovery and purity. The results herein demonstrate a trade-off between process economics and process operability, which must be effectively rationalised to integrate CO$_2$ capture units in the design of low-carbon energy systems.

翻译：低碳可调度电力是可持续能源系统的基石，通过提供负荷平衡来支撑间歇性可再生能源的大规模部署。在此新背景下，化石燃料发电厂必须与能够实现高度瞬态运行的后燃烧碳捕集（PCC）工艺相结合。为同时解决设计与运行挑战，我们开发了一个将工艺设计和技术经济评估相结合的计算框架。其核心是基于变压-变温吸附工艺的高保真PCC数学模型。我们证明，成本最优设计的过程灵活性有限，对烟气进料条件等扰动的响应能力不足。结果表明，通过放宽操作中CO₂回收率的约束可引入灵活性，但会牺牲过程捕集效率。我们发现，吸附法工艺在CO₂回收率和纯度的运行约束下，能够实现显著的灵活性和性能提升。本文结果揭示了过程经济性与可操作性之间的权衡关系，在低碳能源系统设计中集成CO₂捕集单元时，必须对这种权衡进行有效合理化。