The major differences between FAME and HVO
Fuels produced from plant and animal material or waste (biomass) are called biofuels. In principle, you can achieve a CO2 reduction 90% with them, because the CO2 released during the combustion of these fuels is quickly absorbed by new growth. Think, for example, of trees that absorb more CO2 as they grow. However, there are major differences between FAME and HVO, the two main biofuels, and the extent to which they can be used in engines.
FAME (Fatty Acid Methyl Ester) or biodiesel
FAME is made from vegetable and animal oils and fats. The raw materials can vary depending on where in the world it is produced. In Caterpillar engines, to 20% FAME can be blended More is possible, but it comes with significant challenges for the maintenance of the fuel system.
Due to the biological components present in FAME and the oxygen and fuel, bacteria grow at the interface between FAME and free water. These bacteria form flakes when FAME is stored in a fuel tank for a long period, causing filters to become clogged. Additionally, FAME absorbs water easily (it is highly hygroscopic), which only exacerbates this challenge.
FAME must comply with the European EN 14214 standard for the use of biodiesel as fuel for diesel engines. Over time, the quality of FAME deteriorates, partly because its oxidation stability is much lower than that of diesel, due to the remaining oxygen. Therefore, sufficient replenishment of the fuel in tanks is necessary to prevent this. As a rule of thumb, FAME is considered to be up to 6 months shelf-stable in a fuel tank.
FAME can also be present in 'standard' diesel, because within the specifications of the fuel standard EN590 conventional diesel may contain up to 7% FAME. 7% is an established standard and does not mean that more would immediately be a problem.
HVO (Hydrotreated Vegetable Oil) or renewable diesel
HVO is largely made from the same raw materials as FAME: used vegetable oils and waste, such as animal fats, but the production process is different. Due to this difference and because the quality of HVO is the same as that of EN590 diesel and the biofuel BTL (Biomass To Liquid), it is also called renewable diesel.
With HVO, there is no bacterial growth in the bunker because the oxygen has been removed using hydrogen. There is also no oxidation, so the quality remains stable.
HVO can be blended, but can also be used purely. Unlike FAME, 100% HVO can be used without challenges in Caterpillar engines produced after 1990. It is qualitatively as good as or better than standard EN590 diesel.
To make HVO, the used vegetable oil and waste (and for BTL the biomass) must first be gasified. Using a Fischer-Tropsch-like method, the gas is then converted into a liquid.
How do you know what is best to use?
Various abbreviations and names are used for (bio)fuels. Therefore, it is not always clear what exactly is being discussed and what is 'bad,' 'better,' or 'good.' We hope to provide clarity by listing the different (bio)fuels and their characteristics, from 'bad' to 'good.'
| Fossil fuels (diesels) |
|
| EN590 diesel |
Ultra low sulfur diesel with up to 7% FAME blended. |
| GTL | High-quality fossil fuel made from gas. |
| First generation biofuel | |
| FAME (biodiesel) | Relatively easy to blend up to 20% in diesel. Very limited shelf life and challenges due to bacterial growth. |
| Second generation biofuels | |
| HVO (renewable diesel) | 100% HVO can be used without challenges in Caterpillar engines produced after 1990. |
| BTL (renewable diesel) | 100% BTL can also be used without challenges in Caterpillar engines produced after 1990. |
If you are considering switching from EN590 to a renewable diesel or a percentage of biodiesel, we recommend first contacting Pon Power for advice. While no technical adjustments may be required, there are things you need to consider when switching; something we are happy to assist with.
Source, processing, composition, specifications, and application
Below we also provide an overview of the source, processing, composition, specifications, and application of the various (alternative) fuels.
| Source | Fuel | Processing | Chemistry | Specification | Application |
| Petroleum | Diesel | Refining | Paraffins, olefins, aromatics | ASTM D975, EN590, etc. | |
| Vegetable oils, animal fats and used cooking oil | Biodiesel | Esterification | Ester, oxygenated | ASTM D6751 (B100), others | Various blend levels |
| Vegetable oils, animal fats and used cooking oil | Renewable fuel / HVO | Hydrotreating | Paraffin | EN 15940, ASTM D975 | 100% or any blend level |
| Carbon dioxide, hydrogen, other | E-Diesel / Synthetic diesel | Fischer Tropsch, other | Paraffin | EN 15940, ASTM D975, EN590, others | 100% or any blend level |
| Natural gas, synthetic gas, other | Gas-to-liquid | Fischer Tropsch, other | Paraffin | EN 15940, ASTM D975, EN590, others |
100% or any blend level |
What is the deal with the 7% FAME blending in EN590 diesel?
The government requires fuel producers to bring a certain percentage of what they deliver in total to market in biofuels or renewable energy each year.
Since 2015, they must report how much biofuel they have sold how much electricity they have supplied to road transport and transportation. It does not matter in which sector this occurs, as long as the total amount is achieved. Producers can sell the biofuels as 100% or blend them, for example in EN590.
<p>If a producer can sell 100% biofuel at a better price, that will be preferred. However, blending is allowed with lower quality FAME that is more difficult to sell in higher blends or as 100%. Deciding when to choose one over the other is a constant puzzle for fuel suppliers.</p>
So, up to 7% biodiesel can be present in EN590, but it doesn't have to be. Therefore, you never know exactly what you are getting when you refuel.
90%
By using biofuels, you can theoretically achieve a 90% CO2 reduction (CO2 released during combustion is quickly absorbed by new growth).
20%
In Caterpillar engines, up to 20% FAME can be blended. More is possible, but it comes with significant challenges for fuel system maintenance.
EN 14214
FAME must comply with the European EN 14214 standard when traded for use as biodiesel fuel in diesel engines.
7%
Within the specifications of the EN590 fuel standard, conventional diesel may contain up to 7% FAME.
100%
Unlike FAME, 100% HVO can be used without challenges in Caterpillar engines produced after 1990.
2015
Since 2015, fuel producers must report how much biofuel they have sold and how much electricity they have supplied.
MORE INFORMATION
Do you want to know more about FAME HVO differences and the use of biofuels in Caterpillar engines? Please feel free to contact us.