What do we need to know about the changing fuels for our internal combustion engines?

Steve Guy

An article from Steve Guy, Spill Response Accreditation Assessor with the ISAS Accreditation Scheme. Steve has many year’s experience working in the Oil Spill Response Industry, starting with Alba International in 1989 and then Briggs Marine Environmental Services in 1998 where he was Head of Oil Spill Response Training until he retired in March 2020.


Since retiring from a 31-year association with oil spill response and training in response I have become more and more aware that response to an oil spill (fuel) may be different to what I was taught years ago.

Fuels are changing to help our environment and us in the long run. Some fuels are being restricted in its use and other fuels are being replaced with a greener option.

So what do we need to know?

I am sure you will all have seen in the media that the British government has pledged to be carbon neutral by 2050 and that no new cars will be powered by the internal combustion engine after 2030 but as we all know the fuels used in the internal combustion engine are used for many things other than cars.

So over the years industry has been working on creating cleaner (greener) fuels to run our cars, trucks, buses, ships, trains, leisure craft, generators, compressors and the list goes on and on. 

You can see one of the recent changes at the filling station, you now have two types of petrol to chose from E5 or E10 these are a mixture of Ethanal and Petrol E5 5% Ethanol and E10 10% Ethanol. What we need to know is most modern petrol cars will run of either E5 or E10 quite happily but older cars and most small plant engines (generators and so on) NEED E5, E10 can damage them.

There are other new fuels out there commonly called Biofuel, Biofuel is fuel derived from living matter called biomass (usually plant matter). Examples of biofuels include but are not limited to biodiesel, ethanol, and vegetable oil.  

What are the most common biofuels?

Ethanol fuel is the most common biofuel worldwide, particularly in Brazil. Alcohol fuels are produced by fermentation of sugars derived from wheat, corn, sugar beets, sugar cane, molasses and any sugar or starch from which alcoholic beverages such as whiskey, can be made (such as potato and fruit waste, etc.).

In the USA you can top up your muscle cat with E85 which of course is 85% Ethanol

Ethanol, or (ethyl alcohol),

Types of Biofuels

The chemical structure of biofuels can differ in the same way that the chemical structure of fossil fuels can differ. For the most part, our interest is in liquid biofuels as they are easy to transport. The table below compares various biofuels with their fossil fuel counterparts.

BiofuelFossil FuelDifferences
EthanolGasoline/EthaneEthanol has about half the energy per mass of gasoline, which means it takes twice as much ethanol to get the same energy. Ethanol burns cleaner than gasoline, however, producing less carbon monoxide. However, ethanol produces more ozone than gasoline and contributes substantially to smog. Engines must be modified to run on ethanol.
BiodieselDieselHas only slightly less energy than regular diesel. It is more corrosive to engine parts than standard diesel, which means engines have to be designed to take biodiesel. It burns cleaner than diesel, producing less particulate and fewer sulfur compounds.
MethanolMethaneMethanol has about one third to one half as much energy as methane. Methanol is a liquid and easy to transport whereas methane is a gas that must be compressed for transportation.
BiobutanolGasoline/ButaneBiobutanol has slightly less energy than gasoline but can run in any car that uses gasoline without the need for modification to engine components.

The chart above is only a limited list of the biofuels available, covering only the most popular and widely used. It is worth nothing that ethanol is found in almost all gasoline mixtures. In Brazil, gasoline contains at least 95% ethanol. In other countries, ethanol usually makes up between 10 and 15% of gasoline.

The reason for writing this article is to make people think now about which of the new fuels will suit their needs. This sound easy but one of the most commonly used fuel may be taken away from you (by law in the UK)

As from 31st March 2022 RED DIESEL will be restricted to a few specific industries such 

  • Agriculture, forestry, horticulture, fish farming
  • Rail, including passenger and freight
  • Powering non-commercial heating systems (e.g. homes, narrowboats, leisure craft and religious buildings)

There is a lot to think about with all of these things that could affect business, there is a lot of information out there and its not all easy to understand and even when you think you have started to understand the different fuels that are available there is always the other things that most people forget. 

  • Which fuels will be compatible with my machinery?
  • Will the new fuel store in my old fuel system?
  • Will I need to make any changes to my machinery?
  • What happened if I have a spill of this new fuel?
  • With all these changes will I need to review my fuel security?

This article is not going to go into everything its role is to make you think a little longer a little deeper about the new fuels

Some of the things you should understand

Ethanol and Ethanol mixtures Affinity For Water Affinity For Water

Pure ethanol has a high affinity for water, and it’s able to absorb any trace around it or from the atmosphere. This fact is also true for those blends of gasoline and ethanol used to power vehicles. The fact that ethanol has high water attraction capabilities means that it’s difficult to obtain it in its purest form since there will somehow be a trace of water. In fact, manufacturers normally indicate 99.8% pure ethanol. This is especially dangerous for marine users than regular road car users.

When water finds a way into a storage or fuel tank, it goes to the bottom of the tank since water is denser than fuel. This will lead to a plethora of small and big engine problems for your vehicle.  The water attraction property of ethanol is the reason why it’s transported by railroad or auto transport.

Ethanol is Difficult to Vaporize

Pure ethanol is hard to vaporize. This makes starting a car in cold conditions almost difficult, which is why a number of vehicle owners make a point to retain a little petrol, for instance, E85 cars that use 15% petroleum and 85% ethanol.

A common blend used in the USA these days is E85 i.e. 85% Ethanol and 15% gasoline. The mileage provided by this blend is lesser than that of pure gasoline or the E10 (10% Ethanol) blend. However, the benefit of using the E85 blend is that the oil remains clean for a longer time, there is lesser stress on the engine and the overall engine maintenance reduces. The cost of lower mileage gets covered up thanks to these small benefits. Not to mention, the overall reduction of your carbon footprint, which is the one benefit from the use of Ethanol fuel that everybody should aspire for.

What is biodegradable diesel fuel?

Biodiesel is diesel fuel made from vegetable oils, animal fats, or recycled restaurant greases. It’s safe, biodegradable, and produces less air pollutants than petroleum-based diesel. Biodiesel can be used in its pure form (B100) or blended with petroleum diesel.

How much bio-diesel is safe in diesel?

Up to 7% bio-diesel in diesel is considered not to cause any compatibility issues with car fuel systems and there’s no need to mark pumps to tell customers that the fuel may contain biofuel. E10 – petrol with up to 10% Ethanol

What is HVO fuel and how is it made?

HVO fuel? Generally speaking, HVO fuel is considered a sustainable alternative to the more commonly used fossil fuels. Standing for “Hydrogenated Vegetable Oils”, the clue’s in the name. HVO fuel is produced through the hydro-processing of vegetable oils and fats. It is made by reacting vegetable or other oils with hydrogen at high temperature and pressure. The process itself is fairly energy intensive and currently the hydrogen comes from natural gas.

HVO is part of the paraffinic family of fuels which are stable, renewable, sustainable and high quality, making it perfectly suited for a wide range of applications including vehicles, generators and industrial power systems.

HVO meets EN 15940 standards and Fuel Quality Directive 2009/30/EC Annex II so can be used as a direct, drop-in alternative to mineral diesel without modifications to infrastructure or high initial investments.

The immediate problem is one of availability. The world has woken up to the possibilities for HVO and demand is increasing. Currently, supply is limited, however, and not matching demand and the new production plants scheduled to come online are still some way off. As a result, finished fuel is having to be shipped long distances.

So what happens if we have a spill of these new fuels

In many cases where the fuel you have has a percentage of fossil fuel in it you will still have the distinctive odour of the fossil fuel to alert you to the fact that something has gone wrong. By now you should understand the consequences to the environment and your pocket of having a spill. If you are not sure talk to your fuel supplier and your local spill response company. 

HVO is different as there is no fossil fuel within it and so at present little to no recognisable odour is associated with a release, which means you will not smell a fuel leak and it will not be detectable at present with the standard tools which are used like PID’s ( photoionization detector) Portable Gas Monitors typically measure LEL, O2, CO, & H2S the monitors are usually portable & relatively easy to use.  

At the end of the day prevention is better than a cure, ensuring you have a good secondary containment system is essential, having a method of detecting the level of liquid in the secondary system and in particular if there is fuel in that level.  

Fuel Security

When I started this article I hadn’t considered fuel security but a number of acquaintances said the same thing “when fuel prices go up thefts of fuel go up”

But with the changes to “rebated fuel” (red diesel) and the cost increase of having to pay the full fuel duty to run small or large plant on white diesel and of course the possible costs of alternative “green “ fuel I do feel it makes sense to at least consider the security of your fuel.

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