Getting to know biofuels and blends

From a shipowner’s perspective, biofuels and biodiesels may be an attractive option to achieve decarbonisation in shipping when compared with some other lower carbon fuel options. This is especially true if the IMO and EU fully credit the reduction of GHGs (greenhouse gases) on a well-to-wake basis (WTW), as predicted by some institutions.

The demand from other industries for biofuels is already high, which introduces the risk of poorer quality products entering the market. As demand increases, so will the number of different companies that start blending and supplying.

Blended products are usually categorised by their biofuel content. For example, B20 has a 20% biodiesel content where as B10 only has 10%.

At North, we receive numerous enquiries from our Members on using biofuels to reduce their fleet carbon intensity. So, we asked Ian Crutchley and Steve Bee of fuel testing experts VPS to find out more.

Which tests are you carrying out on biofuel blends?

Within the last year or so, we have tested a huge variety of biodiesels, ranging from 3-460cSt in viscosity (@50°C) and with biofuel contents between 1 and 100%.

With regards to the scope of testing, ISO 8217 is always a great starting point despite the ISO specification currently not allowing for residual fuels with >0.5% or distillate fuels with >7% biofuel. But such fuels can still be used via a commercial agreement between the parties. For example, specifying the fuel will be compliant to ISO8217, RMG380 grade, but with exceptions regarding FAME (fatty acid methyl ester) content.

We have seen an increase in the number of biodiesel blends with more than 20% FAME. Tests carried out over and above the tests stated in the tables of ISO 8217 will depend on the CoQ and experience of specific fuels.

Testing during trial phase is stringent and includes but not limited to:

• Combustion performance monitoring
• Corrosivity
• Wax characteristics
• Cold flow properties
• GCMS (Gas Chromatography Mass Spectrometry)

Trialled fuels that prove non-problematic which are placed into regular service may revert to routine ISO 8217 testing. However, we may suggest other tests based on experience including FAME content.

How can owners and purchasers of biofuel blends protect themselves, especially if a CoQ or similar quality assurance is not provided?

Until the marine biodiesel market matures, extreme diligence will be required.  It would not be advisable to take any fuel where a CoQ has not been provided upfront regardless of the supplier. 

It may also be advisable to request the supplier to provide:

• a ‘no objection’ letter from the engine manufacturer
• material compatibility data
• any references or trial data available

It is also worthwhile to talk to a fuel testing lab for an overview of their experience of that product.

Are there fewer quality concerns with products from the major producers?

Usually, the fuel producers have a better control on quality, but they still have quality issues to contend with; it’s just the nature of blended fuels.  It remains to be seen if a biodiesel purchased from an oil major would be better quality, however, the advantage for suppliers that only blend fuel rather than produce, it is that they perhaps have a wider access to blend components in the market.

Our experience with testing biodiesel blends has been linked to field trials between vessel operators and owners which normally provide a better-quality blend.

What about the risks surrounding stability and compatibility?

Stability and compatibility are risks with any heavily blended fuels, and biodiesels are no different.  Again, our experience so far is relatively limited, but biodiesels containing residual fuel components are at higher risk.

As is the case currently with a VLSFO (very-low-sulphur fuel oil) product, we strongly advise avoiding long term storage and any potential for commingling.

How much of a problem is water content leading to microbial growth?

Field trials to date have not highlighted microbial activity, but this may be expected. Microbial activity may develop over time whilst the fuel is stored on board the vessel.

Microbes in biodiesel blends are attracted to FAME content because it is a food source. The presence of FAME also makes it harder to separate water, and in turn microbes, from fuel because it sits in pockets throughout the fuel and is not confined to one location.

This highlights the need to prevent water content in bunkers. Good housekeeping will be imperative, and we suggest:

• Frequent draining of fuel oil settling and service tanks
• Prevention of water ingress into fuel tanks
• Periodical fuel system and storage tank analysis to check for microbial contamination

Is it easy to reverse microbial contamination?

If it’s detected early, it’s easier to treat with a fuel biocide. However, if it is left unchecked and undetected, a microbial issue can result in fuel system choking which, in severe cases, may cause loss of propulsion. A fuel system which is compromised to this level may need manual cleaning.

Will the next ISO 8217 update address biofuel blends such as B10M or B20M?

The ISO committee must submit a draft version of the new ISO 8217 standards by April 2022 if any changes are to be made to the 2023 version. We believe the ISO committee for biofuels are discussing the potential of FAME inclusion into residual fuels oils. However, there is presently no fixed plan to add a ‘Table 3’ for biofuels.

How else can you assist shipowners when preparing for biofuel trials or long-term use?

In addition to testing such fuels, we offer a fuel quality data platform called PortStats based on thousands of analysed samples globally and is set to include biodiesels.

North already takes advantage of this data for the benefit of its Members, currently providing VLSFO bunker analysis results via the MyGlobeView platform.

We can also provide advisory services for biodiesels such as:

• Preparation of vessel’s fuel handling systems for biodiesels
• Handling guidance based on test results
• Guidance on scheduled sampling frequency for microbial activity

Find out more

• Read North’s Signals article on biofuels 
• Visit North dedicated web area ‘Navigating Decarbonisation’
• Explore the VPS fuel quality data layer on MyGlobeView

In VPS we lead through innovation and in partnership with our customers we continue to evolve our testing methods, technologies, and advisory services.