DUT Testing on Methanol and Ethanol Marine Fuel Applications
- 2 days ago
- 2 min read
Technical testing validates alcohol fuels as practical marine fuel pathways
As shipping accelerates its search for scalable low-carbon fuel solutions, alcohol-based fuels such as methanol and ethanol are gaining increasing attention. Both fuels are liquid at ambient conditions, 100% miscible with each other, and recognised under the IMO’s interim guidelines for methyl and ethyl alcohol fuels.
Against this backdrop, GCGF commissioned Dalian University of Technology (DUT) to conduct a testing programme to evaluate the combustion, performance and emissions characteristics of methanol, ethanol and methanol-ethanol blends in a diesel-ignited two-stroke marine engine platform. The study provides important technical insights into how alcohol fuels can perform under marine-relevant operating conditions.
Testing Scope
The programme assessed 10 fuel types, including neat methanol, neat ethanol, a range of methanol-ethanol blends, denatured ethanol, and ethanol-water blends. Testing was conducted across ISO 8178 E3, D2 and E2 cycles, with diesel pilot fuel used to initiate combustion. This reflects a practical dual-fuel engine strategy similar to approaches being developed for future alcohol-fuelled vessels.
Key Findings
The testing showed that both methanol and ethanol can be used safely and effectively in a diesel-ignited two-stroke marine engine configuration.
Methanol demonstrated faster combustion characteristics, supported by its simpler molecular structure, higher oxygen content and lower viscosity. Ethanol also performed reliably, with blended fuels showing stable combustion behaviour across the tested ratios.
Importantly, no abnormal combustion behaviour was observed. Maximum pressure rise rates remained within safe design limits, supporting the technical viability of alcohol fuels in marine engine applications.
Performance and Emissions
Both methanol and ethanol achieved comparable thermal efficiency across the test cycles. Blended fuels maintained consistent performance, suggesting that fuel selection and blending ratios can be adjusted based on supply, cost, emissions objectives or operational needs.
On emissions, methanol generally showed lower CO, THC and particulate mass emissions, while ethanol presented different particulate characteristics due to its molecular structure. NOₓ emissions varied depending on load and combustion phasing but remained within expected ranges for dual-fuel systems.
Blending Flexibility
A key finding from the testing is the full compatibility of methanol and ethanol as blended alcohol fuels. The fuels demonstrated no phase separation issues, and performance could be adjusted through different blending ratios.
This supports the view that methanol and ethanol should not be seen only as competing pathways, but as compatible fuel options that can be used independently or together depending on market conditions, availability and policy frameworks.
Supporting Alcohol Fuels in Shipping
The DUT testing programme adds to the growing body of technical work supporting alcohol-based fuels for maritime decarbonisation. It demonstrates that methanol, ethanol and their blends can deliver stable combustion, comparable engine performance and operational flexibility in marine engine applications.
For the shipping sector, this is significant. As regulatory pressure increases and the industry evaluates practical near-term fuel options, alcohol fuels offer a pathway that combines technical readiness, liquid-fuel handling advantages and growing supply chain relevance.
The findings reinforce the role of methanol and ethanol as scalable, deployable and complementary fuel pathways in shipping’s multi-fuel transition.
Download the Full Report
The full report, Comparative Test on the Diesel-Ignited Methanol/Ethanol Two-Stroke Engine is available here:
