Modeling the Reduction of Ship Exhaust Emissions through CO₂ Capture/Chemical Conversion and SO₂ Seawater Scrubbing

Abstract

Developing innovative, energy-efficient technologies to capture CO 2 from marine emissions and convert it represents an effective way to move toward a circular approach to reduce CO 2 emissions. Additionally, SO 2 removal, as a shortterm interim solution for the current maritime sector, allows the use of less desulfurized/expensive fuels to meet International Maritime Organization emission standards. In this context, we investigated an integrated process of capturing CO 2 / SO 2 onboard ships and converting captured CO 2 , thus initiating a process close to carbon neutrality. CO 2 absorption by monoethanolamine and SO 2 scrubbing with seawater were envisaged in packed-bed columns, whose hydrodynamics and performance were analyzed under vertical, inclined, and rolling conditions using three-dimensional (3D) Eulerian models to understand their behavior under changing ocean states. CO 2 conversion via an integrated process combining a sorption-enhanced reverse water gas shift and sorption-enhanced methanol synthesis was proposed. By including a reverse water gas shift and in situ H 2 O removal, CO and methanol yields were significantly improved.