In 2024 there were about 6.3 million diesel fuelled vehicles on Australian roads, accounting for around 30 per cent of all registered vehicles – and growing.

One of the drivers of that growth is road transport, with 630,000+ registered rigid trucks on the road nationally.

With those kinds of numbers in play and with Australia’s New Vehicle Efficiency Standard now in effect, it’s no surprise we are also major users of diesel exhaust fluid (DEF). Australia currently burns through about three million litres a year and growing, with most of that consumed by our long haul trucking fleets.

Given its critical importance for modern diesel engines, diesel exhaust fluid (DEF) is critical for the nation’s supply chain, including the mining and agriculture sectors. Supplies form an important part of our fuel security planning, with the government investing $49.5 million over four years from 2022 to boost local manufacture.

This means while AdBlue is still the most widely used DEF brand in Australia, there is growing competition from a number of other locally manufactured options.

But what’s the difference and how can you get the best value out of your DEF supply?

What is diesel exhaust fluid (DEF)?

DEF is a key component in lowering emissions from diesel engines and improving efficiency in modern diesel engines fitted with selective catalytic reduction technology.

It’s non-toxic, colourless and odourless and is made of a specific combination of urea and deionized water. Its chemical makeup sits at around 32.5 per cent concentrated urea and 67.5 per cent demineralised water, making it non-flammable and safe for the environment in the case of a spill.

Is DEF the same as AdBlue?

AdBlue is a registered trademark for a specific brand of diesel exhaust fluid and is owned by the German Association of the Automotive Industry (VDA).

It is primarily used in Europe and Australia.

Other brands of DEF are widely used in the United States, Canada, and other markets. Like AdBlue, DEF is composed of 32.5% urea and 67.5% deionized water, making it chemically identical to AdBlue.

In Australia, vehicles equipped with SCR technology can use any diesel exhaust fluid that meets the ISO 22241-1 standard for quality and purity and the AUS-32 specifications. This international standard ensures that the product is free from contaminants that could damage the SCR system.

Any fluid that complies with this standard can be safely used in any diesel vehicle equipped with SCR technology.

Importantly, DEF is not the same as water and urea solution, which can cause damage including build-up of calcium deposits, causing reduced efficiency and lost time.

How does DEF work?

Diesel engines generate high levels of nitrogen oxide – a serious pollutant with significant health risks. To meet emissions standards, manufacturers needed to develop more advanced catalytic conversion technology.

They did this by splitting the oxidation and reduction reactions across two steps, using a liquid reducing agent high in urea. DEF is manufactured to specific ISO standards to optimise this process.

Its active ingredient is the urea. The other key element is the de-ionised water, which means that mineral ions such as iron, chloride and sodium are removed. This is so the chemical reaction or catalyst is more precise.

In vehicles, DEF is stored in its own tank, separate from the diesel and is added to the outgoing exhaust gas by an automated dosing control system. When the fluid is sprayed into the exhaust system the water component evaporates, helping the urea spread evenly. The urea breaks into ammonia and carbon dioxide and as part of this, the NOx is converted by the ammonia into water and nitrogen.

Storing DEF

Since DEF is essential for reducing nitrogen oxide emissions, improper storage can have serious effects, not only for your fleet but also for your bottom line.

In harsh conditions like those in many parts of Australia, constant exposure to high temperatures can shorten the fluid’s shelf life and reduce its performance. This means higher maintenance costs. It can also mean increased vehicle emissions which can result in hefty fines.

The proper storage temperature for DEF is between -5°C to 30°C. Kept in a dry, shaded area, away from direct sunlight, it has a shelf life of 12 months plus.

Bulk storage is ideal for large fleets, helping reduce costs with bulk savings and fewer transport fees – particularly in regional areas. It also helps improve refuelling efficiency, particularly when operating from a central depot or dedicated refuelling hubs.

Preventing contamination

Contamination with even small amounts of dirt, fuel or other foreign particles can also spoil your DEF. To avoid this, it’s important to use well maintained storage tanks and dispensing equipment – ideally, pumps and hoses designed for DEF will minimise exposure to contaminants.

Using non-dedicated equipment can cause serious problems because even very small quantities of fuel/oil/lubricant can cause serious and expensive damage to your SCR system.

Purchasing your DEF from high-quality suppliers also ensures consistent quality. It’s a good idea to also test stored fluid regularly to check for impurities – this will keep your business compliant and protect your fleet, minimising the need for expensive downtime.

Top tips are:

• Choose the right tank. DEF is corrosive to aluminium which is why DEF tanks on vehicles are made from stainless steel or non-corroding, highly durable composite material.
• Check dispensing equipment. It’s important that seals, hoses, insulation and o-rings are made from quality materials that won’t react with the product. It’s also important to regularly test and clean dispensing equipment for crystallisation and to check nozzles are in full working order and won’t jam or remain open for too long.
• Watch the temperature. Store DEF within a temperature range between 0 and 30°C. Ensure the product is protected from direct sunlight and properly sealed when not in use. Evaporation due to storage in hot conditions can cause evaporation and change the water-urea mix.
• Test for quality. DEF can be stored safely for about 12 months. If you need to store it for longer it’s important to check it before use to ensure it still meets specifications. If the liquid is cloudy, don’t use it.

The F.E.S Tanks solution

Your storage tank is the frontline of defence to keep DEF in top condition and protect your vehicles.

Even a small amount of contamination – including traces of diesel, oil or rust – can lead to serious issues.

F.E.S Tanks offers standalone DEF tanks in sizes from 3,000-20,000 litres featuring self-bunded design and stainless steel construction, mechanical overfill protection valve, easy maintenance to internal tank with removable lid and forklift lifting points for easy relocation.

For a cost-effective refuelling solution for modern diesel fleets, the F.E.S range also includes integrated AdBlue/diesel tanks that keep installation costs down while making optimum use of space.

The F.E.S. range of integrated DEF/diesel Grande tanks come in sizes up to 110,000 litres (10,000/100,000) and are designed to handle larger storage requirements – ideal for depots and to service the needs of transport fleets.

Ask the experts about F.E.S DEF storage and dispensing solutions by calling 1300 651 391.

 

With Australian road users going through about three million litres of AdBlue fluid every week, it’s safe to say it’s a critical component in the nation’s supply chain.

And with Australia’s New Vehicle Efficiency Standard now in effect, usage is only going to increase. Euro 6 standards will apply for all existing heavy vehicle models in Australia from November 2025. The standards applied from January 1 for all new cars, SUVs and light commercial vehicles introduced into Australia. Practically, this means introduction of selective catalytic reduction (SCR) technology across a broader range of models.

With this in mind, effectively managing AdBlue supply and storage is more important than ever.

What is AdBlue?

AdBlue is the trademarked name for a diesel additive called diesel exhaust fluid that reduces the emissions generated by modern diesel engines. It can also be called AUS 32, which stands for Aqueous Urea Solution 32 per cent.

Made using a mixture of demineralised water (water with bacteria and ions removed) and a high concentration of urea, it can effectively reduce nitrogen oxide emissions by up to 90 per cent. This makes a real difference in meeting industry-wide emissions targets.

Its chemical makeup sits at around 32.5 per cent concentrated urea and 67.5 per cent demineralised water, making it non-flammable and safe for the environment in the case of a spill.

What does Adblue do?

Simply put, AdBlue reduces toxic exhaust emissions in diesel vehicles. Diesel engines generate high levels of nitrogen oxide – a serious pollutant with significant health risks. To meet emissions standards, manufacturers needed to develop more advanced catalytic conversion technology.

They did this by splitting the oxidation and reduction reactions across two steps, using a liquid reducing agent high in urea. AdBlue is manufactured to specific ISO standards to optimise this process.

Its active ingredient is the urea. The other key element is the de-ionised water, which means that mineral ions such as iron, chloride and sodium are removed. This is so the chemical reaction or catalyst is more precise.

In vehicles, AdBlue is stored in its own tank, separate from the diesel. An automated dosing control system adds it to the outgoing exhaust gas. When the fluid is sprayed into the exhaust system the water component evaporates, helping the urea spread evenly. The urea breaks into ammonia and carbon dioxide and as part of this, the NOx is converted by the ammonia into water and nitrogen.

About 90 per cent of the NOx can be eliminated in this way. To put this another way, it would take the emissions of over 60 new trucks to match the emissions of a well-maintained 20-year-old truck without this technology.

How much AdBlue does a vehicle use?

The amount of AdBlue used varies between vehicles and depends on driving conditions.

On average, AdBlue consumption is about 5 per cent of diesel consumption for trucks – that’s about 5 litres of AdBlue for every 100 litres of diesel, or about 1.5 litres for every 100km on the road.

For cars, most modern diesels have an indicator on the dashboard that reminds a driver when AdBlue levels reach their lower limit. On average, it needs to be refilled after 5,000 to 10,000 kilometres.

Buying and storing AdBlue

AdBlue is non-hazardous or dangerous, but there are some considerations to ensure optimum storage.

Top tips are:

• Check the standards. Your AdBlue should display the certification of the German Institute of Standardisation DIN70700, the International Organisation for Standardisation ISO 22241-1, and meet AUS – 32 specifications. AdBlue is not the same as water and urea solution, which can cause damage including build-up of calcium deposits, causing reduced efficiency and lost time.
• Avoid contamination. Don’t use old diesel or oil containers to transfer AdBlue into the tank. Any non-dedicated equipment can contaminate AdBlue. Even very small quantities of fuel/oil/lubricant can cause serious and expensive damage to your SCR system.
• Choose the right tank. AdBlue is corrosive to aluminium which is why DEF tanks on vehicles are made from stainless steel or non-corroding, highly durable composite material.
• Check dispensing equipment. It’s important that seals, hoses, insulation and o-rings are made from quality materials that won’t react with the product. It’s also important to regularly test and clean dispensing equipment for crystallised AdBlue. Check nozzles are in full working order and won’t jam or remain open for too long.
• Watch the temperature. Store AdBlue within a temperature range between 0 and 30°C. Ensure the product is protected from direct sunlight and properly sealed when not in use. Evaporation in hot storage conditions can change the water-urea mix.
• Test for quality. AdBlue can be stored safely for about 12 months. If you need to store it for longer it’s important to check it before use to ensure it still meets specifications. If the liquid is cloudy, don’t use it.

The F.E.S Tanks solution

Your storage tank is the frontline of defence to keep AdBlue in top condition and protect your vehicles.

Even a small amount of contamination – including traces of diesel, oil or rust – can lead to serious issues.

F.E.S Tanks offers standalone AdBlue tanks in sizes from 3,000-20,000 litres. Each features self-bunded design and stainless steel construction, mechanical overfill protection valve, easy maintenance to internal tank with removable lid and forklift lifting points for easy relocation.

For a cost-effective refuelling solution for modern diesel fleets, the F.E.S range also includes integrated AdBlue/diesel tanks that keep installation costs down while making optimum use of space.

The F.E.S. range of integrated AdBlue/diesel Grande tanks come in sizes up to 110,000 litres (10,000/100,000) and are designed to handle larger storage requirements – ideal for depots and to service the needs of transport fleets.

Ask the experts about F.E.S AdBlue storage and dispensing solutions by calling 1300 651 391.

 

 

Powering the future of sustainable flights with SAF

Australians love their travel and with huge distances to cover between domestic destinations and beyond, our aviation fuel use continues to rise. 

And we’re not the only ones – the aviation industry contributes about 2.5% of the world’s total carbon and accounts for about 8% of global oil production. 

But as commercial aircraft operators around the world work towards net zero goals, it’s proving one of the most difficult industries to decarbonise. 

The demand for jet fuel is growing, particularly in the Asia Pacific region – demand in Australia is expected to increase by 75 per cent before 2050, with Boeing forecasting around 42,600 new commercial jets will be needed over the next 20 years. 

At the same time, the limitations of technology make electric engines and alternative fuels like green hydrogen impractical for long haul flights, meaning commercial airlines and defence forces are increasingly looking for solutions in sustainable aviation fuels. 

Sustainable aviation fuel – a drop-in replacement for traditional aviation fuel solutions – is quickly gaining a foothold and is already used in more than 250,000 flights. 

What is sustainable aviation fuel?  

Sustainable aviation fuel (SAF) is a low carbon alternative to traditional jet fuel made from renewable sources like waste or crops. 

SAF works with existing aircraft infrastructure. The CSIRO’s Sustainable Aviation Fuel Roadmap says it offers the largest potential to reduce carbon emissions over the next 30 years in all aviation segments. 

It’s currently made from five main types of raw materials: oils and fats, sugar and cereal, municipal solid waste, wood and agricultural residue, or renewable energy and carbon, which are used to replace a proportion of the crude oil feedstock. 

Depending on the feedstock, SAF can achieve a reduction in CO2 emissions of at least 70% and up to 85% compared to conventional kerosene-based fuel – a significant incentive for airlines when CO2 compliance costs are increasing at around 3.4% a year.  

Already, Airbus aircraft are 50% SAF compatible. To address supply, the CSIRO and Boeing are working together to explore production opportunities and Australia and New Zealand are partnering with a view to becoming an integral part of a growing sustainable aviation fuel supply chain. 

At Emerald in Queensland, a multi-grain processing facility is being built specifically to support the SAF industry with a capacity to process about 70,000 tonnes a year once complete to support an industry which is projected to be worth up to $3 billion annually by 2030. 

How is SAF made?

Each different feedstock uses a different production technology which must be approved by the ASTM before being commercially deployed. 

 Most of the SAF supplied today is made by converting waste fats, oils, and greases into synthetic kerosene using hydrotreated esters and fatty acids (HEFA).  

 Standalone units work by turning sustainable feedstocks into synthetic kerosene (SK), which is certified under the ASTM D7566 standard. It is then blended with up to 50 per cent conventional jet fuel, certified to ASTM D1655 or Defence Standard 91-091 and supplied as a conventional Jet A/Jet A-1 fuel. 

 Alternatively, SAF can be produced through co-processing, where up to 5% sustainable feedstocks are hydro-processed alongside fossil feedstocks in a refinery. 

The CSIRO is researching use of gas to liquid technology to create SAF from sustainable sources.

 

Sustainable aviation fuel – Pros and Cons

 Pros – Clean technology and efficiency 

 The good news is SAF is safe to use in any aircraft that currently use jet fuel. 

 It achieves lifecycle carbon emission savings of up to 80 per cent – good news for the environment and for reducing compliance costs – this year, tests in Germany with aircraft running on 100% sustainable aviation fuel also found reductions in soot and contrails.  

 SAF also has a higher energy density than conventional jet fuel, requiring slightly less fuel to be carried and combusted during flight, thereby improving fuel efficiency. 

Cons -Price and supply: Fuel is one of the largest operational expenses for commercial airlines and the cost of SAF has until now far outstripped traditional Jet A1 fuel. 

 In 2020, the overall cost of jet fuel was $0.5 per liter. Meanwhile, the cost of SAF was $1.1 per litre, more than double the price of conventional jet fuel. 

 But the tide is turning and with jet fuel prices growing at about 1% a year, the efficiencies sustainable fuel can achieve and growth in supply are expected to make it roughly equal to jet fuel and carbon emission costs by 2037. 

 The CSIRO says while Australia has the feedstock, a lack of on-shire refining capability may also contribute to higher costs and supply constraint in the short-term. 

Storing sustainable aviation fuel

In more good news, SAF can be stored in the same fuel infrastructure as other jet fuels and the same principles apply for ensuring fuel stays fresh and in good condition. 

The F.E.S Tanks range of portable, self-bunded double-walled aviation fuel tanks provides a hassle-free solution for AVGAS, Jet A1 and SAF that meets or exceeds Australian Standards, with none of the hassle of cleaning and inspecting underground tanks. 

F.E.S aviation fuel tanks are also made with a sloping floor and without interior baffles, ensuring a free drainage floor pan and allowing for the safe removal of water from aviation fuel as part of your daily maintenance program. 

For expert advice on your sustainable aviation fuel storage needs, call the team at F.E.S Tanks to discuss the aviation fuel storage solution that’s right for you. 

What’s so special about avgas aviation fuel?

General aviation is a critical industry in Australia, particularly for regional communities. 

It delivers education and health services, tourism, regional health and education services, supports agriculture and enables emergency services. 

In most cases, the aircraft involved are piston engine aircraft powered by avgas aviation fuel.  

What is avgas?

Avgas, short for aviation gasoline, is an aviation fuel used in planes driven by spark-ignited internal combustion piston engines. It is different from jet fuel, which is kerosene based, and from the petrol used in motor vehicles because it needs to power higher performance aircraft engines.  

A fuel’s octane rating measures its ability to withstand compression in the engine without detonating – piston engine aircraft require a high-octane fuel. For this reason, the most common types of avgas still contain tetraethyl lead, which assists with engine lubrication and helps prevent engine knocking (premature detonation). Because tetraethyl lead is toxic, only the minimum amount needed to achieve the required fuel octane rating is used – and manufacturers are working to find safer and more sustainable alternatives. 

How is avgas classified?

Different grades of avgas have different maximum lead concentrations and are identified by the octane rating of the fuel tested to both “aviation lean” and “aviation rich” standards. These standards relate to the lean engine settings typically used for cruising and the rich settings used for take-off and when full power is required. 

Different types of avgas are identified by their octane ratings and are coloured for easy identification. 

Types of avgas 

There are two main avgas grades (100 and 100LL low lead) used in the general aviation community.  

• Avgas 100 is the standard high-octane fuel for aviation piston engines. It has a high lead content and is dyed green. The two major specifications for Avgas 100 are the ASTM D910 and UK DEF STAN 91-090. The two specifications differ in antioxidant content, oxidation stability requirements and maximum lead content. 

• Avgas 100LL is a lower lead version of Avgas 100. This grade is listed in the same specifications as Avgas 100, namely ASTM D910 and UK DEF STAN 91-090. Avgas 100LL is dyed blue. 

• In the United States, the Federal Aviation Administration has approved an unleaded avgas, the G100UL. In Australia, unleaded avgas is still in development, with the Civil Aviation Safety Authority warning in 2023 that it should not simply be substituted for leaded fuel. Shell is among major suppliers working on development of an unleaded avgas with similar octane performance to Avgas 100LL, but testing and development is still underway. This fuel is controlled by the specification ASTM D7960. 

Getting avgas storage right

Avgas is extremely flammable and toxic. Storing it properly in accordance with regulations is critical for safety in the air and on the ground. 

Storage and transfer points provide the greatest opportunity for fuel contamination, with surfactants, water, particulates and misfuelling the most common contaminants for aviation fuel.  

• Water contamination is possibly the greatest threat to aviation fuel. Free water can enter the fuel through degraded seals, accumulation at low points in the tank or pipeline or condensation from air entering the tank. In piston-powered aircraft, water can collect in the carburettor float bowl and stop the engine. This is why regular testing with a water detecting kit is essential. 

• Particulates like rust, scale, lint and dust can cause engine stalling and damage. While rust is most common, other solids that can cause this type of contamination include dust and pollen, which can enter through tank vents or slip past seals. Rubber particles and fibres can also enter through damaged hoses and filters, while microbial infestation can create slimy residue. Avoid refuelling from fuel cans, which increases the risk of particulate contamination.

•  Surfactants are are soap or detergent-like compounds that can be introduced into the fuel during processing and transfer, including through cross-contamination and fuel additives. While small amounts are common, excessive amounts reduce the surface tension between water and the fuel. This can cause water and small particles in the fuel to remain suspended rather than settling into the sumps. Surfactants also tend to collect in filter elements making them less effective. 

F.E.S Tanks avgas storage solutions

F.E.S Tanks avgas fuel tanks are made to the highest quality standards with a 100% stainless steel inner tank and all fittings are also made of stainless steel, minimising the risk of rust and particle contamination or water leaks. They’re also built without an interior baffle to ensure free drainage and allow for the safe removal of water. 

Talk to the experts at F.E.S Tanks to get the most out of your avgas fuel storage. 

What is a Diesel Bug?

A diesel bug is a common term for a myriad of microscopic organisms that grow in the fuel-water interface present in any static bodies of diesel – particularly fuel tanks. From yeasts, to fungi and algae, these bugs share a few typical features.

• They require water and warmth for growth.
• A fast reproductive cycle allows them to multiply in numbers very quickly.
• As the older ‘bugs’ die their bodies and waste products accumulate in the tank.
• This results in the formation of a layer of sludge and slime.

Whilst you may or may not have heard of the term “diesel bug” or “diesel bug contamination”, you may have heard of “fuel contamination” which can be very closely linked to the presence of water and diesel bugs.

Did you know your tank breathes?

When we talk about air and water in tanks, they often exist together – and one of the reasons is because your tank breathes.

Each day, either through temperature fluctuation or the movement of fuel, the air pocket within a tank expands and contracts. This is why storage tanks are fitted with a breather – a valve that allows the tank to relieve this excess pressure and vacuum.

As air is introduced via the breather, it brings moisture in from the atmosphere with it, and cooler conditions within the tank can allow this moisture to condense. As these little droplets of water collect, they eventually fall into the fuel itself, and create a water-fuel interface – the perfect home for diesel bugs.

 

A full tank has limited airspace for the transfer of moisture via condensation.

 

Each of these droplets is like a swimming pool of space for more microbes and spores to colonize. With a constant supply of energy from the diesel, and dissolved oxygen from the water, this creates a perfect environment for these bugs to quickly take over.

Over time, if these water and bug issues are not handled correctly, there is a real risk of structural and mechanical damage to contaminated tanks, vessels, vehicles and machinery.

Slime, Grit & Machine Failure – Is Your Fuel Contaminated?

Sometimes the first symptoms of diesel bugs and contaminated fuel are not noticed, but the consequences cost us countless dollars each year in maintenance and damages.

If you notice any of these tell-tale signs, make sure to inspect your tank, and if you are unsure how, always check with your supplier –

• Clogged filters & the presence of slime or grit on tank floors.
• Pitted or corroded components in machinery and fuel systems.
• Darker fuel, or the presence of a foul smell.
• Rough running machinery from a particular fuel source or tank.

Any of these symptoms are indicators that fuel contamination may be affecting your diesel systems, and the key is vigilance, inspection and treatment before the problem multiplies.

Catching the Bugs – Inspection Protocol & Treatment

Ideally, inspection protocols and the correct treatment programs will allow us to identify, control, and protect our fuel reserves from diesel bugs. So what steps do we recommend?

The correct inspection protocols can catch fuel contamination before damages occur.

Prevention

For prevention, we recommend diesel biocide products. While these agents are great at controlling the numbers of living bugs – they do not remove existing sludge and slime, as this is primarily composed of dead bugs and their waste products.

These biocide products are not a permanent solution. Similar to hospitals and antibiotics – diesel bugs within your tank may develop resistance to these products, so we advise to use them appropriately as a preventive agent and to ask us for advice if you feel they are being overused.

Inspection & Fuel Testing

Inspecting your tanks regularly is a vital part to maintaining any fuel storage system, and many tanks have inspection hatches for this purposes.

Inspection routines should include monitoring your tank temperature, checking for leaks or checking for water in fuel reserves. Also, water condensation can be minimized by trying to keep the tanks full, and appropriate monitoring of tank levels is of utmost importance.

An extra level of safety can be gained by applying fuel testing methods to your maintenance schedule. This is particularly valuable as by testing the fuel itself, you can detect contamination that may not be visible to the naked eye or via inspection hatches.

Draining, Cleaning & Fuel Polishing

A tried and true method, draining and cleaning your fuel tank is essential to routine maintenance and should be performed at regular intervals as advised by your suppliers and local guidelines.

Any fuel removed during these processes can also be filtered and conditioned, which is commonly known as fuel polishing.

Fuel polishing is a series of filtration techniques designed to eliminate contamination, and in some scenarios can even save some of your fuel from being discarded.

 

Draining and cleaning is an ideal time to make sure that all water and existing debris is removed from your fuels.

 

Should you have any concerns or issues and require a second opinion, please get in touch for a chat.

Aviation Fuel – Powering machines in the sky

Australia’s demand for aviation fuel is growing as use of air services continues to boom, with current domestic demand for jet fuel sitting at about 770 ML per year based.

It’s not hard to see why, with more than 5.2 million passengers taking off on domestic routes (including charter flights) in Australia in April 2024 alone, while domestic cargo movements totalled 24.9 thousand tonnes in the same month – up 5 per cent on the previous year.

With demand projected to increase by 75 per cent before 2050, understanding aviation fuel and the infrastructure that keeps it in top condition is central to supplying that need – a critical lifeline for businesses in sectors from tourism, passenger and cargo transport to emergency services, farming, scientific services, survey work and defence.

What is aviation fuel?

There are two main types of aviation fuel used in general aviation: jet fuel and AVGAS.

• Jet fuel – including Jet A, Jet A1 and Jet B – is a refined kerosene-based liquid used to power turbine engines including turboprops and jet engines. While there are several main varieties, Jet A1 is the most commonly used jet aviation fuel worldwide because it has a low freezing point. In general, jet fuel is designed to be stable and predictable, including at extreme temperatures.
• Avgas – For smaller propellor and piston-engine aircraft like those used for crop dusting and agriculture, Avgas (short for aviation gasoline) is the fuel of choice. Avgas is highly volatile, because it changes from a solid (liquid) to a vapour state at a temperature usually much lower than room temperature.
• Sustainable Aviation Fuel (SAF) – The CSIRO is working with manufacturers to develop a sustainable aviation fuel (SAF) industry in Australia. Sustainable aviation fuel is a biofuel alternative to fossil-based aviation fuels produced from renewable resources including agricultural waste, animal fats, vegetable oils and municipal waste, and significantly reduces aircraft carbon emissions. Global demand for SAF is expected to underpin an industry worth up to $23 billion worldwide by 2030.

Why is aviation fuel coloured?

Aircraft engines are designed to use a specific grade of fuel and oil, and getting this wrong can mean big trouble including power loss, engine failure and seriously reduced engine. Aviation fuel colours help quickly identify the fuel grades and prevent costly errors.

Civil aviation fuel is produced in three grades and colours – Avgas 100 is green, Avgas 100LL (low lead) is blue and Jet A1 turbine fuel is colourless or straw coloured.

Contamination in aviation fuel

It’s the responsibility of the aircraft operator to ensure fuel used in the plane is not contaminated, degraded or incorrect, so getting storage and transfer right is critical.

Common types of contamination can include water, micro-organisms and mixing fuels.

Water contamination

Water in aviation fuels can be suspended or free. Suspended water appears in the form of droplets – a high concentration will make the fuel look cloudy or hazy. Free water can begin as water dissolved in contaminated fuel. It can also be caused by condensation or leakage in underground tanks or inside the aircraft’s fuel tanks.

Condensation can happen inside a partially filled fuel tank when warmer air above the fuel meets the cooler surface of the tank, often on descent. Standing the plane overnight with partially filled tanks increases the risk of condensation, so the Civil Aviation Authority recommends standing the aircraft with full tanks.

To minimise the risk of water contamination aircraft should be checked before the first flight of the day, after each fuelling and always after taking on board fuel that is potentially contaminated with water.

CASA also recommends that aircraft fuel tanks and sumps be sampled before fuelling to remove condensation, and that any fuel is checked for the presence of water before transfer.

Testing for water can be difficult when refuelling from drums, because it may be difficult to access the lowest point of the drum. Water detecting paste, capsules or testing paper are some common alternative testing methods.

Micro-organisms and organic contamination

Another risk related to water contamination is micro-organisms including bacteria and fungus which can grow in jet fuel when water is present. This can cause slime on the inside surfaces of fuel tanks or dark-coloured contamination at drain points.

Bacteria and fungus can cause serious corrosion in fuel tanks and clog fuel filters, screens and fuel control units.

It’s important to check Jet A1 storage tanks regularly for slime or corrosion.

Biocides can be used to reduce risk.

Incorrect fuel

Contamination with the wrong type of aviation fuel can cause aircraft fuel system or engine damage – an expensive problem – and even result in engine power loss or failure in flight. If Avgas is contaminated with turbine fuel its antiknock and volatility characteristics will be inadequate for reciprocating engines, while turbine fuel mixed with AVGAS can result in damaging lead deposits in the turbine engine. While most turbine engines can operate on Avgas (usually with limitations and extra service required by the engine manufacturer), Jet A1 in a gasoline engine will cause total failure or severe degradation of performance.

If an aircraft is refuelled with incorrect fuel, corrective action must be carried out before operating the aircraft.

Handling aviation fuel

There are strict regulations around handling aviation fuel.

Avgas is highly volatile, because it changes from a solid (liquid) to a vapour state at a temperature usually much lower than room temperature. Splashing volatile fuel in an open container – for example when washing oily parts – or pouring a fuel sample into an open container can create an explosive free fuel mixture in the air.

That’s why all aviation fuel containers, including vehicles, are clearly marked with the grade of fuel they contain. Drums of aviation fuel must also be labelled in accordance with the Australian industry standard.

Having the right fuel transfer equipment is an important part of safe fuel handling.

Getting aviation fuel storage right

Choosing a high-quality aviation fuel storage system is the best way to minimise fuel contamination and keep your fuel, your aircraft and your people safe.

The F.E.S Tanks range of portable, self-bunded double-walled aviation fuel tanks provides a hassle-free solution for both AVGAS and Jet A1 fuel that meets or exceeds Australian Standards, with none of the hassle of cleaning and inspecting underground tanks.

F.E.S aviation fuel tanks are also made without an interior baffle, ensuring a free drainage floor pan and allowing for the safe removal of water from aviation fuel as part of your daily maintenance program.

Whether you’re storing 1000 litres or 100,000 litres, call the expert team at F.E.S Tanks to discuss the aviation fuel storage solution that’s right for you.