As Ships Risk “Unseaworthy” Rating, Warns IMO, Bioenergy Is a Key to Saving Them

by Ron Cascone (Nexant) Reuters reported on November 16, 2017 an International Maritime Organization (IMO) declaration that ships not meeting stack sulfur emission limits through reductions in the sulfur content of their fuel or by installing scrubbers risk being declared “unseaworthy”. Ship owners and refiners are in a quandary about how to comply with the IMO rules finalized last year requiring shippers worldwide to cut sulfur emissions from 3.5 percent to 0.5 percent by 2020. The IMO stated that there would be no delays or exceptions in enforcement, whether or not the industry takes the necessary steps for compliance. It warned of the consequences that all stakeholders face if they do not comply, that non-compliant ships considered “unseaworthy” would have their charter affected, and also indemnification for insurance claims. However, enforcement of the global sulfur regulation is handled by individual countries acting as either flag states or port states, and no one can predict how the enforcement will play out when push comes to shove.

The Digest has been following the developments around the IMO global sulfur rule since at least 2011, and most recently with, “Singing a song in Singapore: GoodFuels Marine, BHP, and MPA collaborate on biofuels during closed-door roundtable”, September 24, 2017, by Helena T. Kennedy.

At the risk of mixing metaphors, this IMO regulatory drama is an impending “train crash”, which Nexant has studied in its recent report, PERP 2017S7: Technologies to Meet New Bunker Fuel Specifications, June 2017. As with aviation, shipping is a global issue, except that many more diverse solution options are feasible. This report reviews in-depth the history of marine fuels (“bunkers”), the IMO rule, the technology options available to refiners to provide compliant fuels, the shipowners’ options for stack gas scrubbing, and LNG bunkering. The report evaluates practical issues, economics for each solution over a wide spectrum of geographies, and world markets. It looks at conventional and advanced technologies to make compliant low sulfur fuels. It also looks at wet scrubbers, dry and membrane stack sulfur removal, and other options. The report analyzes engine technologies as relevant to low sulfur fuel utilization and other issues. Nexant is also doing single client consulting to dig even deeper into these subjects.

Heavy, high sulfur marine bunkers have been the “junkyard” of the petroleum refining industry since ships stopped burning coal between WWI and WWII.

The biofuels option

Now, besides the US Navy and other navies, all of global commercial shipping will have to become a “green fleet”. We see this as a potential opportunity for biofuels, especially biodiesel and HVO (hydrogenated vegetable oil, or renewable diesel), DME (fossil or bio), and perhaps upgraded biomass-based bio-oil. For the most desirable solutions of biodiesel and HVO, there is not enough natural seed oil and animal fat to make much of a difference without a break-through like development of leaf-oil (e.g., by Australian CSIRO and others).

DME is another longer-tern zero-sulfur solution. It has roughly the properties of LPG, except that it has a high cetane number (average of 58 versus diesel’s average of 49), making it an ideal diesel engine fuel, but it has 54 percent the energy density of diesel fuel. Its energy density is also only 13 percent lower than LNG, but 24 percent higher than methanol. DME can be stored similarly and as easily as LPG for re-fueling and on-board (but not the same as for liquid fuels like diesel), in tankage that is cheaper, and that is much less challenging than, say, for storing and handling LNG.

Technologies are being developed to “activate” (convert) CO2 to renewable liquid biofuels such as methanol by utilizing “stranded”, or excess, renewable electricity. Nexant recently published a report, Biorenewable Insights: Carbon Dioxide to Chemicals and Fuels, which covers this subject, with more to come. DME is relatively easily and cheaply produced by dimerizing methanol. There are hyper-scale versions of this technology as well as small-scale for distributed generation (e.g., from Oberon Fuels). Importantly, fossil-based DME supply can seamlessly be transitioned to bio-DME at any time in the future. Nexant has an excellent report on this subject, Biorenewable Insights: Methanol/DME (2015). READ MORE