Technoeconomic optimisation of systems for liquefaction and purification of captured CO₂

To scale up carbon capture technologies for the future needed capacity, costs must be reduced for all process steps in the value chain. In this study, a technoeconomic optimisation of a system for liquefaction and purification of captured CO₂ with an external refrigeration cycle was made. The operational parameters for different system layouts were optimised to deliver liquid CO₂ at 7 bar, 15 bar, and 53 bar. The overall costs of the system decreased up to 17 % with increasing delivery pressure, which was primarily caused by a reduction in power consumption of up to 23 %. Optimisation showed, that increasing the liquefaction pressure and reducing the load on the refrigeration cycle was the major cost reduction  river. The overall costs found at the different system layouts varied up to 20 % for each delivery pressure, which emphasised the importance of designing and optimising the conditioning process to the given transportation pressure.