Dynamic operation of liquid absorbent-based post-combustion CO₂ capture plants

Abstract

Dynamic (or flexible) operation has been proposed as a strategy to reduce the impact of integrating post-combustion CO2 capture (PCC) into power plants. It provides a means for counteracting ongoing variations in the composition of flue gas and absorbent, and also accounts for dynamic variations in carbon and electricity pricing, and electricity demand. For example, in periods of low energy demand, electricity prices will be lower and capture rates may be ramped up accordingly. During high-demand periods, electricity prices will be higher, and capture may be turned down or switched off completely. Flexible PCC operation can also coordinate the balance between electricity demand and legislative requirements for CO2 emission reductions, to improve the economic feasibility of PCC. However, dynamic PCC operation imposes process disturbances when the CO2 capture plant is ramped up or turned down. The immediate and long-term effects of these disturbances are unclear. Thus, recent research is now focusing on the feasibility of flexible PCC operation on a technical basis. Dynamic modeling and pilot plant studies will improve our understanding of dynamic PCC behavior and enable process control to be optimized.