CO2 post combustion capture with a phase change solvent. Pilot plant campaign

• A pilot campaign for CO2 capture using a phase change solvent was performed.
• From lab experiments a model for the absorber section was built.
• The model was implemented in CO2SIM and the absorber section was simulated.
• The DEEA/MAPA solvent showed a potential to operate at low SRD.
• The system shows more flexibility than MEA and can produce CO2 at high pressures.

A new class of solvents, commonly referred to as phase change solvents, has a huge potential to significantly reduce the energy requirements of the CO2 capture process. Aqueous solutions of DEEA and MAPA can form two liquid phases upon CO2 loading depending on the amine concentrations. The 5M DEEA/2M MAPA mixture was tested in the Gløshaugen (NTNU/SINTEF) pilot plant. The phase change solvent showed to operate well in the pilot plant. Neither high viscosity nor foaming issues were noted. Absorption was reasonably fast and the CO2 stripping in this system was easy due to the presence of the tertiary amine. Moreover, the system was able to operate at significantly lower specific reboiler duty and reboiler temperatures compared to the benchmark 30 wt.% MEA. The solvent was, however, more volatile than MEA and better control to avoid solvent losses is required. The experimental pilot campaign for the DEEA/MAPA system was validated toward a simulation model implemented in our in-house code CO2SIM. A total of 18 runs from the campaign were simulated with CO2SIM. A simplified thermodynamic model of the DEEA/MAPA system was successfully implemented in CO2SIM and can be used for further simulations of large scale plants.