Techno-economic analysis of amine-based post-combustion carbon capture process with flexibility considerations

Amine-based post-combustion carbon capture (PCC) process is a key technology for efficient CO${}_2$ emission reduction, and owing to high technological maturity, its detailed design and operation have become an active area of research. While there exists a well-known trade-off between economic process design and flexible process operation, research efforts leveraging such trade-off for PCC process are rather scarce. To this end, in this work, a systematic procedure is proposed for the flexible design of PCC processes. Specifically, a flexible process design is defined as a design which can handle every possible realization of uncertain parameters (in this work, flowrate and CO${}_2$ composition of flue gas coming from power plant) without violating any process constraint in the most economical way. To find such a design, a grid search algorithm is proposed, where the values of design variables are iteratively changed so as to increase the flexibility index (FI), which is defined as the ratio of the operable region in the uncertain parameter space. Through a case study, it was shown that the most economic process design has a FI value of 0.1597, which is very low, and by spending 4.2% more annual cost, the flexible design was obtained.