Studying the effect of solvent properties in treatment design within CO₂ Integration Networks

Carbon Dioxide Integration mainly targets the recovery of CO₂ streams, and assesses the allocation of those recovered streams into CO₂-using sinks, with an overall aim of attaining a minimum cost of a CO₂ network that could meet a prescribed emission target. Meeting emission targets often introduces numerous challenges, especially when energy intensive processes are involved. Hence, CO₂ Integration aims to identify appropriate CO₂ capture, allocation, and utilization options. There exists numerous processes (or CO₂-using sinks) that convert CO₂ streams into value added products, while generating revenue in some cases. However, many CO₂ sink options may be costly, especially if a high purity CO₂ stream is required in the process. Thus, the incorporation of treatment units is imperative, to separate CO₂ gas from the remaining gaseous emission material, which is in fact the most expensive design step in CO₂ integration systems. This study focuses on assessing the effect of varying the temperature of the solvent to be used in the treatment stage of CO₂ on the overall performance of the entire integration network attained. A MINLP formulation has been established based on key design parameters whilst taking into consideration important technical performance constraints that effectively describe the system to be assessed. A more detailed cost model for the treatment units was developed, to establish the effect of varying the emission reduction targets onto the overall performance of CO₂ integration systems.