Investigation of an intensified carbon capture process for onboard application

Abstract

This study investigates an intensified carbon capture process designed to overcome the spatial constraints of shipboard applications. The objective is to minimize equipment size while maintaining performance, making carbon capture more practical for maritime use. A rotating packed bed (RPB) was evaluated as an alternative to conventional packed columns, using a 17 MW cargo ship as a case study. The RPB-based system was compared with a previously developed conventional design in terms of equipment dimensions and energy demand.

Process models were developed for the absorber and stripper units. The results showed that RPBs can significantly reduce the size of absorption columns while achieving comparable CO₂ removal efficiency. Although absorbent regeneration was not significant, the enhanced heat transfer characteristics of the RPB suggested potential reductions in reboiler duty. A full RPB-based absorption–desorption cycle was also simulated, and the influence of key parameters on process performance was assessed. The results indicate that while the RPB can achieve a size reduction of more than threefold compared to a conventional packed column, this advantage entails approximately 25 % higher energy consumption, equivalent to 4.97 GJ per ton of captured CO₂. The considerable size of a single RPB absorber also raises concerns regarding the mechanical feasibility of operating such a large rotor. Nevertheless, multi-stage configurations present a promising pathway for practical implementation. For example, a three-stage RPB can reduce the absorber’s outer diameter from 5.3 m to 3.1 m, with only a slight increase in energy demand to 5.19 GJ per ton of CO₂.