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体系的基石，它为大规模部署间歇性可再生能源提供了负荷平衡的补充。在这一新背景下，化石燃料发电厂必须配备能够高度瞬态运行的后燃烧碳捕集（PCC）工艺。为了同时应对设计与运行挑战，我们开发了一个将工艺设计与技术经济评估相结合的计算框架。该框架的核心是一个用于变压真空吸附过程的高保真PCC数学模型。我们证明，成本最优设计的过程灵活性有限，对烟道气进料条件等扰动的响应能力不足。结果表明，通过放宽运行过程中CO₂回收率的约束可以引入灵活性，但这以牺牲过程的捕集效率为代价。我们发现，基于吸附的过程能够在满足CO₂回收率和纯度运行约束的前提下，实现显著的灵活性和性能提升。本文的研究结果揭示了过程经济性与可操作性之间的权衡，这种权衡必须得到有效协调，才能在设计低碳能源系统时集成CO₂捕集单元。