Onboard Carbon Capture for Circular Marine Fuels

Area of Science:

• Marine engineering
• Environmental science
• Chemical engineering

Background:

• The maritime industry faces pressure to reduce emissions, with low- and zero-carbon fuels like methanol and natural gas as key alternatives.
• Carbon-based fuels still produce significant pollutants during operation, necessitating advanced emission control strategies.

Purpose of the Study:

• To explore the integration of circular economy principles and carbon capture and utilization (CCU) technologies in the shipping industry.
• To evaluate the economic, technical, and environmental viability of methanol and natural gas as circular marine fuels.

Main Methods:

• Proposal of a closed-loop system for onboard CO2 capture using chemical absorption.
• Onshore utilization of captured CO2 with electrolytic hydrogen to regenerate marine propulsion fuels.
• Economic and environmental assessment of methanol and natural gas as circular fuels.

Main Results:

• Natural gas offers a potential 65% CO2 emission reduction by 2050, while methanol offers 55%, both with a 91% carbon capture rate.
• Economic premiums are estimated at $339/tonCO2 for methanol and $260/tonCO2 for natural gas.
• Transitioning to circular fuels may increase operational costs by a factor of 3-6 compared to conventional fuels.

Conclusions:

• Circular marine fuels, particularly natural gas and methanol, show significant potential for emission reduction in the shipping industry.
• The economic feasibility and cost implications of CCU technologies require careful consideration for widespread adoption.
• Integrating circular economy principles through CCU is a viable strategy for a more sustainable maritime sector.