Maritime News

Biodiesel Critical To UK Climate Change Agenda

The Renewable Transport Fuel Obligation is one of the UK’s main policies for reducing greenhouse gas emissions and was implemented in 2008 as a result of the EU Renewable Energy Directive.   The RTFO is an obligation on large suppliers of petrol and diesel to supply a certain percentage of renewable fuel to the UK market.  The scheme works by setting an annual obligation on suppliers to supply “renewable fuels”, in practice this usually means biofuels. Current supply targets are at 9.6% and are due to rise to 14.6% by 2032. 

Biodiesel Causing Problems For Boaters

Increasing numbers of boats have reported fuel system blockages and engine failures in the last couple of years. This issue has been widely reported in the maritime media and are not related to the well known issue of diesel bug contamination. River Canal Rescue reported an “uncharacteristic peak in fuel-related component breakdowns due to a new problem called ‘sticky fuel’. RCR said its marine engineers had responded to two or three cases per week on the inland waterways”.

Boat Chat Focus - What price FAME?

A diesel engine on any boat likes a simple life and only wants three things to keep it happy: clean air, clean oil and clean fuel. The first two are pretty easy to supply with a little care and maintenance in the form of quality filters, regular oil changes and daily pre-start checks.  Clean fuel used to be easy to provide as well, but in recent times this has become an ever increasing challenge for boat owners.

Climate change and the global desire to reduce internal combustion engine emissions has forced the major fuel suppliers to change the formulation of their fuels.  Those readers of a certain age will recall, perhaps with some fondness, the smell that came from a well tuned engine running on fully leaded fuel.  The lead additive went years ago, and with good reason given the health risks it posed. 

Modern fuels often come with a wide range of additives such a lubricity agents, cetane increasers and cleaning agents all of which are intended to improve the basic fuel. These are usually found in premium fuels whilst supermarket fuels are specced down to a price and lack some of these enhancements. The current advice from motoring organisations is to pay for one tank of premium fuel in every 3 or 4 fill ups, unless your vehicle needs premium fuel all the time.

Increasing numbers of boats have reported fuel system blockages and engine failures in the last couple of years. This issue has been widely reported in the maritime media and are not related to the well known issue of diesel bug contamination. River Canal Rescue reported an “uncharacteristic peak in fuel-related component breakdowns due to a new problem called ‘sticky fuel’. RCR said its marine engineers had responded to two or three cases per week on the inland waterways”.

The fuel game has changed in the last couple of years as bio-diesel has become increasingly popular.  Bio-diesel is a form of fuel manufactured from oils and fats to create a diesel substitute.  Some engines can run on pure bio-diesel but most cannot without modification, hence the practice of blending it with normal fuel has become commonplace.  Fuel forecourt pumps are now marked with B5, B7 or B10 depending on the percentage of bio-diesel blended into the fuel.

The process used to make bio-diesel is called transesterification which produces Fatty Acid Methyl Ester (FAME) or Fatty Acid Ethyl Ester (FAEE).  This is the product making waves in the maritime world as it has been linked to the increasing problem of stored diesel ‘going off’.  Darrell Broscomb at Tooley’s Boatyard in Oxfordshire recently wrote on this subject (see Further Reading below) having had several customers come in with blocked fuel systems.  He and others describe it as ‘sticky diesel’ which has caused filters, injection racks and nozzles to all block.  The only way to fix the problem is to strip down the entire fuel system, clean all components and refill with clean fuel.

Some of the wider drawbacks of FAME in fuels include:

• Poor flow characteristics in cold temperatures aka ‘waxing’

• Water contamination due to its hydrophilic nature

• Encourages diesel bug growth

• Increased chance of injector fouling

• With 90% of the energy density of standard diesel fuel consumption will increase

• Increased exhaust emissions of NOx which contribute towards acid rain

• Higher solvency can cause issues with fuel system rubbers

• Gradual degradation of fuel due to oxidation and hydrolysis

Modern blended bio-diesel does not appear to store well compared to fuel from the ‘good old days’ which could sit in your garage for several years and still be fine.  This poses a real dilemma for boat owners storing their boats ashore for winter.  The traditional advice was to fill your tanks to minimise condensation which could lead to the formation of diesel bug.  But what use is avoiding the dreaded bug if when you come to re-launch after 5 months ashore the fuel system blocks within 10 minutes as the fuel has gone sticky?

Some marinas are now taking to sourcing FAME free diesel which is a good start but this may not be a commercially or environmentally sustainable position.  Boat Chat’s thoughts are that more fundamental change is needed from the drawing board through to daily operations.  If the diesel that boat owners need is changing then the way we buy, store and use that diesel needs to change.  Here are some thoughts:

• Store vessels over the winter with the least amount of fuel in the system as possible

• Ideally, drain the fuel system down and put the fuel in your car / van / helicopter 🤣

• Design fuel tanks with better drains to allow for debris and contaminants to be removed

• Install two smaller tanks rather than one large one giving a second fuel supply capability

• Have a separate filtering system for the second tank

• Install a 2 micron fuel polishing system to keep the fuel in top condition

• Buy the best fuel you can afford from reputable sellers

• Consider using fuel conditioning additives

No easy answers here and every type of boat will have a different set of priorities and opportunities to design in fuel resilience.  Second generation fuels such as HVO (Hydrotreated Vegetable Oil) and third generation bio-diesels are in varying stages of development which may help alleviate some of the drawbacks.

Share your thoughts by throwing us a line at [email protected]

Testing fuel is beyond the scope of most general condition surveys and is normally the preserve of specialist contractors.  Assessing and commenting on the fuel storage, filtering and supply arrangements is however very much within scope.  Being mindful of the challenges posed by modern bio-diesels should help inform the observations and recommendations made in survey reports.  Some questions that should be in the surveyor’s mind might include:

• What material is the tank / tanks made of?

• What is the general tank arrangement - single / double / cross linked / day tank?

• If fitted with more than one tank, does each tank have its own filler?

• Does the fuel tank have an easy to access and remove inspection hatch?

• How hard would it be to clean contaminated fuel out of the tank?

• Does the tank have a decent sized drain plug?

• What are the primary and secondary fuel filtering arrangements?

• How easy is it to access and change the filters at sea?

• Is there a secondary propulsion source?

• How long has the vessel been ashore – how old is the fuel?

• Is the seal on the deck filling point in good order?

Product Review

To help mitigate the downsides of modern diesel fuel, Marine 16 has an additive called Diesel Fuel Complete which contains cetene improvers, lubricity improvers, detergent and an antioxidant and biocide to improve storage.  Designed for continuous use every time you fill the tank, the dose rate is 100ml per 100 Litres.

Marine 16 are a small UK company based in mid-Wales.

🎄Christmas Is Coming 🎄

Find Inspiration For Presents

It’s December and the number of shopping days until Christmas is dwindling FAST. If you need inspiration and present ideas for the boat owner or marine surveyor in your life or as a treat for yourself check out our collection of great ideas at Kit.Co 

Many thanks to Dave Hartley for supporting this issue of Boat Chat.  Dave is currently enjoying a mid-life Gap Year on his narrowboat ‘Pedestal’.  Take five with a cuppa and check out his blog:

Boaty Terminology

Fuel Bunker – The traditional name given for the storage compartment for solid fuels, typically coal, from the era of stem powered ships. The term is less common these days when liquid fuels proliferate and are stored in tanks. Whilst small craft have adopted the language of the garage forecourt and either re-fuel or top up, the re-fuelling of large ships is still referred to as a bunkering operation.

Links To Further Reading

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