Onboard CO2 Capture Process Design using Rigorous Rate-based Model

The IMO has decided to proceed with the early introduction of EEDI Phase 3, a CO2 emission regulation to prevent global warming. Measures to reduce CO2 emissions for ships that can be applied immediately are required to achieve CO2 reduction. We set six different CO2 emission scenarios according to the type of ship and fuel, and designed a monoethanolamine-based CO2 capture process for ships using a rate-based model of Aspen Plus v10. The simulation model using Aspen Plus was validated using pilot plant operation data. A ship inevitably tilts during operation, and the performance of a tilted column decreases as its height increases. When configuring the conventional CO2 capture process, we considered that the required column heights were so high that performance degradation was unavoidable when the process was implemented on a ship. We applied a parallel column concept to lower the column height and to enable easy installation and operation on a ship. Simulations of the parallel column confirmed that the required column height was lowered to less than 3 TEU (7.8 m).