Ship & Boat International: Jan/Feb 2014
Unless shipowners and operators are happy to blow their budgets on exorbitantly priced low-sulphur marine fuels, it is clear that the marine sector requires workable alternatives in order to meet the increasingly stringent IMO and US Environmental Protection Agency (EPA) requirements regarding emission control.
Until now, two alternatives to MDO have dominated much of the debate; the installation of exhaust after-treatment systems, or ‘scrubber’ technology; or adoption of LNG as fuel when navigating designated emissions control areas (ECAs) or similar emissions restriction zones. Scrubber technology would enable operators to bypass costly low-sulphur fuel, but would entail a spell in drydock for what could prove a costly retrofit.
On the other hand, while the launch of sub-40m LNG tugs last year demonstrates that natural gas tanks can be fitted to smaller vessels, this might not be the case for all small-scale retrofits and, despite the optimism of many LNG backers, the more cautious marine operators have noted that the LNG bunkering network is still not quite as comprehensive as it could be.
However, as viable as both methodologies remain, it is important to remember that other avenues exist. Battery bank technology is coming on leaps and bounds for short-haul operators, and methanol has also been touted as a clean means of NOx, SOx and particulate reduction, without the need for costly scrubber installation or dependency on cryogenic tanks (see Ship & Boat International November/December, pp36-38).
Now, Marine South East (MSE), a UK-based consortium of maritime interests, has launched a new project, entitled Glycerine Fuel for Engines and Marine Sustainability (GLEAMS), which is set to investigate the possibility of deploying glycerol (aka glycerine) as a low-emission, low-risk fuel for marine diesel engines.
MSE won the tender to undertake the project from the UK Technology Strategy Board and the Defence Science and Technology Laboratory, and the consortium will work alongside Lloyd’s Register (LR) and Aquafuel Research Limited, the latter of which has already used glycerol to fuel standard diesel engine-driven combined heat and power (CHP) generators.
Simon Powell, MSE operations director, says: “There is a global over-supply of glycerol, a by-product of the expanding biofuel industry.” GLEAMS intends to analyse the advantages and drawbacks of using this substance and, according to MSE, initial information makes it an attractive contender. He tells Ship & Boat International: “The combustion of glycerol is more thermally efficient than that of MDO / HFO and, therefore, the basic carbon reduction calculation is improved. Glycerol has no sulphur emissions, reduces particulates to practically zero and produces very low NOx emissions.
“Glycerol is also non-toxic, water soluble and requires no criteria for vapour risk or fire risk it is nearly impossible to ignite accidentally.” Regarding carbon emissions, Powell says: “The EU Renewable Energy Directive quotes crude glycerol as resulting in 0% carbon; however, cleaned fuel grade glycerol would probably result in 2-3% of the carbon level of MDO or HFO.”
He adds that glycerol has a low energy density when compared directly to fuel oils, but that this can be compensated for by an increased level of efficiency. Similarly, users would need to carry a larger volume of glycerol to attain the operational results expected of fuel oils, but the low-hazard nature of glycerol means that it can be easily incorporated into vessel hull space.
A certain amount of engine adaptation would be required, and this factor remains a key issue for GLEAMS. Powell hints: “Adaptation would include: a means of glycerol fuel storage; fuel piping; automated fuel valves; automated inlet air valve installation; and exhaust catalyst installation.
Also, if the standard engine and control systems are at a low level, then additional automation hardware and software may be required.” Whether this means that a combination of ‘glycerol + scrubber installation’ happens to prove cheaper than ‘standard MDO/HFO + scrubber installation’ remains to be discovered. Powell comments: “On land, internally coated steel fuel tanks or stainless steel tanks are preferred when burning glycerol, but the marine requirements need to be defined.”
However, MSE is keen not to jump the gun before the GLEAMS assessments are concluded. The project will initially focus on the small vessel sector, having identified “potential early adopters” as including ferries, survey and fishing vessels, dredgers and patrol and leisure craft all vessels that require limited volumes of fuel, normally drawn from a single source, for their daily operations. This is also partly due to the lack of an extensive distribution network for glycerol.
At a later stage, the substance will undergo land-based engine trials, supervised by LR and Redwing Environmental. The first GLEAMS workshop will be hosted by LR in London on 27 February 2014 and MSE is keen for qualified parties to get in touch and contribute to the project. Relevant organisations are invited to contact the group at