Smaller craft are candidates for glycerine

Glycerine is a by-product of the bio-fuel industry. A working group, Glycerine Fuel for Engines and Marine Sustainability (Gleams Project), is championing glycerine as a viable alternative fuel for smaller craft and boats. Initial project funding for validating and certifying the use of glycerine as a marine fuel was provided by the United Kingdom Technology Strategy Board and the Ministry of Defence Science and Technology Library.

In February Gleams organised a seminar in London to present the fuel and explore its potential for commercialisation. The event was by invitation only and attendees spanned the worlds of class, manufacturing, ownership and academia, among others.

Glycerine, said the project partners, has a number of properties which would appear to lend itself for marine applications:

• It burns with higher efficiency than diesel

• Very low NOx emissions

• No sulphur emissions

• Virtually no particulate matter

• Non-toxic, water soluble and nearly impossible to ignite accidentally

• Requires modification only to the external engine aspiration system

• Readily retrofitted

• Engine technology proven through use in combined heat and power plant

The fuel also has a relatively low energy density compared to fossil fuels, meaning a greater volume would have to be carried for a given range. Glycerine’s low-hazard nature would allow storage in locations currently unsuitable for more hazardous conventional fuels. The initial focus will be markets where limited volumes of fuel are required and bunkering typically takes place at a single location.

In an open discussion at the February meeting, held under the Chatham House Rule, a range of technical, regulatory and commercial questions were fielded.

From a technical perspective, attendees heard that heated tanks would not normally be required but may be required for operations in low ambient temperatures. Glycerine can be circulated around a vessel for heating.

If water does enter the fuel it remains usable (up to 30 per cent fuel) but the reduced calorific value would be a problem. Water is completely miscible in glycerine so its anti-bacterial properties are maintained. You do not get a fuel/water boundary layer.

The fuel is said to have 10 times the lubricity of diesel, but does not work with standard lube oil. Project partner Aquafuel owns the intellectual property for a suitable renewable oil it would obtain from Fuchs, one of the world’s largest manufacturers of lubricants, and would be used with Aquafuel additives. Glycerine’s shelf life is put at five years.

Glycerine is said to be suitable for all types of compression-ignition engines. Electronic ignition systems would need to be re-programmed in consultation with the engine manufacturer. Engines will need pre-heating modifications, if the intention is to start up using the fuel. The preferred arrangement is to start on diesel and then switch to glycerine – which can be done at full power.

Performance and emissions testing on a glycerine-fuelled engine had not been carried out at the time of the February meeting. This, said the project partners, would be done at a later stage using a duty cycle specified by Lloyd’s Register.

From a supply perspective, the expectation is that sources and the cost of fuel-grade glycerine will change as demand and production capacity increases. Enzymatic/biological production of biofuels could bring a step change in the cost of fuel-grade glycerine. Similarly, production of glycerine directly from salt-water algae could also deliver an increase in glycerine production. The University of Greenwich is developing large-scale production of glycerol from these algae. There is a big advantage over conventional efforts to produce fuel from algae in that the production does not compete with food production for fresh water and good agricultural land.

Potential early adopters are: offshore support vessels; ferries; port/pilot boats; fishing vessels; dredgers; marine police and other commercial and leisure marine craft, including super yachts.

The project has progressed since the February meeting. At the Seawork International 2014 exhibition held in June in Southampton, visitors were able to see the world’s first glycerine-fuelled marine engine operating aboard an Alicat workboat owned by Dalby Offshore. The project’s test engine, a Cummins C44-D5 generating set, was displayed as a stand-alone system with emissions-monitoring equipment providing real-time analysis of exhaust gas. With operation on a dual-fuel system, visitors were able to see the significant reduction in emission levels when the engine was switched from diesel to glycerine operation.

Gleams Partners

• Aquafuel Research Ltd

• Gardline Marine Sciences Ltd

• Lloyd’s Register EMEA

• Marine South East Ltd

• Redwing Environmental Ltd FLET