CO₂ capture from IGCC by low-temperature syngas separation and partial condensation of CO₂

The use of refrigeration to obtaining partial liquefaction and physical phase separation of CO₂ from shifted synthesis gas (syngas) is an interesting technology alternative to the use of chemical and physical solvents as well as membranes. By presenting the principal layout and energy potential of a conceptual low-temperature CO₂ capture process for integrated gasification combined cycle (IGCC) applications, this work challenges the traditional view on low-temperature CO₂ capture. Process-level simulation results for the low-temperature syngas separation processes show competitive results in comparison with conventional solvent-based capture processes. Solvent-based technologies capturing CO₂ in gaseous phase require large amounts of power for CO₂ compression. In comparison, an important advantage of the process described in the present work is the capture of liquid CO₂, enabling pumping instead of compression. This considerably lowers the power consumption required for pressurisation of captured CO₂.