Pilot-scale CO2 capture demonstration of stripper interheating using 30 wt% MEA at a Waste-to-Energy facility

Post-combustion CO2 capture is a widely recognised technology for controlling industrial CO2 emissions. However, issues like the substantial energy demands for solvent regeneration still need to be solved. The current work aims to discuss the outcomes of process optimisation within a pilot-scale CO2 capture facility by implementing interheating in the stripper to reduce energy consumption. The pilot-scale experiments were executed at Amager Bakke, a Waste-to-Energy plant in Copenhagen, Denmark. These tests used 30 wt% Monoethanolamine as the solvent. A semi-lean solvent from the middle of the stripper is withdrawn for external heating by an interheater and fed to the stripper at the same height. A steam generator with adjustable electrical duty is used as the heat source for the interheater. The novelty of this work lies in the pilot scale demonstration of stripper interheating at an industrial facility, which has seldom been done. The objective is to experimentally demonstrate the performance of the Interheating configuration at the pilot scale and analyse the potential improvements in the energy consumption of the process. The interheating experiments were conducted by varying the reboiler duty in the range of 12 to 20 kW and the interheater duty in the range of 2 to 5 kW while maintaining a solvent flow of 267 kg/h and a flue gas flow of 99 kg/h. The results provide several possible scenarios, are discussed in detail, and are compared to previously obtained base case results. While maintaining a capture efficiency of around 83%, stripper interheating has demonstrated a specific reboiler duty of 2.71 GJ/tonne CO2 compared to 3.71 GJ/tonne CO2 achieved by the base case operation. A 3% reduction in the specific reboiler duty was achieved by interheating at a capture efficiency slightly over 90%. A preliminary model based on the experimental results has shown a further reduction of SRD to 2.25 GJ/tonne CO2 at high capture efficiencies.