Life cycle greenhouse gas emissions and cost of marine transport with conventional fuels and methanol

In this study, the production and use of renewable-based methanol as a low carbon intensity fuel for a SUEZMAX tanker is evaluated for energy transport from Saudi Arabia to Asia (Japan) and Europe (the Netherlands), in comparison to the conventional fossil-based fuels. Renewable-based methanol production has been modeled in all three regions from hydrogen, produced with solar or wind energy, and carbon dioxide (CO₂) captured from sources relevant to each region. The Well-to-Wake life cycle GHG emissions analysis and life cycle cost analysis was performed for the two types of trips of the SUEZMAX tanker operating on renewable-based methanol, natural gas-based methanol, liquefied natural gas (LNG), very low sulfur fuel oil and high sulfur fuel oil. A sensitivity analysis was performed by varying the cost and carbon intensity of hydrogen production based on annual variation in renewable energy in the three regions, as well as changing the source for CO₂ captured to produce renewable-based methanol in each region. Sensitivity analysis results for life cycle cost (399 to 921 million US dollars) and life cycle emissions (0.5 to 2.1 million metric tonnes) were used to evaluate the cost of carbon abatement, which was observed to be the lowest (3 to 12 US dollar per metric tonne of CO₂) when the hydrogen cost was assumed to be $1/kg. Of the three regions examined, Saudi Arabia was the location for renewable-based methanol production with lowest life cycle emissions (0.5 to 0.8 million metric tonnes) and cost (588 to 597 million US dollars), while Europe was shown to be the next most cost-effective region for renewable-based methanol production.