Comparison of Single-Tower and Two-Tower Processes for Absorption of Carbon Dioxide From Marine Engine Exhaust
Journal
Emission Control Science and Technology
Journal Volume
12
Journal Issue
1
Start Page
7
ISSN
21993629
Date Issued
2026-06
Author(s)
Abstract
Reducing greenhouse gas (GHG) emissions, particularly CO2, is a significant issue in addressing global warming and climate change. Marine CO2 emissions are also a major concern. The International Maritime Organization (IMO) has implemented numerous regulations to reduce GHG emissions from international shipping. Due to certain limitations and challenges for shipboard operation, post-combustion carbon capture technology is considered the most promising strategy in the near term for maritime applications. In this work, two different absorbents, an amine solution and a sodium hydroxide solution, are considered for the absorption of CO2 from marine exhaust. For each absorbent, two processes are considered: a single-tower process and two-tower process. In a two-tower process the absorbent is regenerated on the ship, while in a single-tower process fresh and spent solution are stored onboard before spent solution is offloaded at port. Although single-tower processes reduce onboard equipment complexity, they require substantial volumes for lean and rich solutions, which impose practical limitations on the achievable CO₂ removal rate under shipboard space constraints. Aspen Plus and sea-trial data are used to model the processes for application on a bulk goods transport ship. The study aims to compare the operational feasibility of both systems under the constraints of a moving ship.
Subjects
Chemical absorption
CO2 emission
MEA
Onboard carbon capture and storage
Process simulation
Sodium hydroxide
Publisher
Springer Science and Business Media Deutschland GmbH
Type
journal article