A new technical and economic study of an 82,000-dwt bulk carrier indicates that retrofitting existing tonnage for methanol dual-fuel capability could contribute to emissions reductions of up to 220,000 tonnes, especially in segments where fleet renewal is slow and operating patterns are complex.
The analysis produced by the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping is focused on medium-sized bulk carriers, including Kamsarmax vessels, which account for a significant share of sector emissions. These ships, which are often operating in the tramp trade, face challenges in adopting alternative fuels due to variable routing and limited access to bunkering infrastructure.
With the bulk carrier fleet still largely dependent on conventional fuels, retrofitting is expected to complement to newbuilding activity. The study finds that methanol offers a viable pathway for conversion, supported by its chemical properties, which enables integration into existing vessel designs without requiring extensive redesign.
The MMMZCS report concludes that such retrofits are technically feasible with no critical safety risks identified following hazard assessment. Design work covering fuel storage, tank configuration and onboard integration has been validated through an Approval in Principle from ClassNK. There are trade-offs, however, which includes some loss of cargo capacity and the need to manage installation schedules to limit off-hire periods.
According to the study: ‘By changing fuel to bio-methanol, the vessel can save about 220,000 t-WTW CO2eq over 20 years – substantially reducing its emissions.’ This supports the role of bio-methanol in reducing lifecycle emissions in segments such as bulk shipping where fuel flexibility is limited.
There is still uncertainty around the economic case as the analysis identifies fuel cost as the central variable influencing investment decisions: ‘Even with the regulations in place, the business case for retrofitting appears to hinge on the price of bio-methanol’. Sensitivity modelling suggests that a retrofit could break even over the vessel’s remaining life at fuel prices between $743 and $904 per tonne, depending on trading patterns.
