What you need to know about alternative fuels: Bioethanol and biodiesel

The arrival of electric cars is almost inevitable, and the aim is for them to become the industry standard. The pursuit of zero emissions has become the main goal for brands, which is why they invest heavily to reach it. But, apart from those battery-electric and hybrid models, there is another type of vehicle that runs on other fuels.

These alternative fuels receive less publicity and are less well known, but they are an excellent option for getting around in a vehicle without significant polluting gas emissions and allowing it to operate efficiently. These fuels are bioethanol and biodiesel, among others. We offer you some facts to help you get to know alternative fuels better.

Bioethanol

Bioethanol is a fuel made from vegetable oils. Its main source is material obtained from corn and cotton stalks. These products undergo a chemical process that makes it possible to use them as fuel for vehicles. It can be used unblended or in various blends with other fuels.

Bioethanol has other sources, such as that obtained from sugar beet, molasses, sweet sorghum, potato, cassava, wood and some agricultural citrus residues, so Spain could be a producer of this type of fuel.

The ethanol content of the blend determines when it is most practical for each type of engine. For example, blends with a higher ethanol content are poorly suited to conventional engines fitted to most vehicles. In this case, engines that have to run on bioethanol need more resistant materials.

Ethanol has a much higher octane rating than petrol, around 105 octane, so the materials in the engine must be adjusted to withstand the presence and use of ethanol as a vehicle fuel. The cold-start system requires a different setup from that used for petrol or diesel. Adding petrol to the blend allows the engine to start more easily, so a E85 blend is normally used, containing 15% petrol and 85% ethanol.

With this blend it is possible to reduce polluting emissions by up to 50% compared with the same car running on a 100% petrol or diesel engine. Among the drawbacks of bioethanol, it is often pointed out that growing crops to produce it pushes up food prices and leads to the deforestation of large areas for cultivation.

Biodiesel

Biodiesel is a type of fuel made from organic waste products and can be used by many conventional diesel engines. Its characteristics mean that biodiesel produces fewer pollutants than ordinary diesel, making it a good choice as a fuel.

To make it, oil obtained from plants such as mustard, soya, flax, rapeseed, sunflower, palm and hemp is used, and even cooking oils can be used to produce this type of fuel.

These two alternative fuels have very little presence in the market and are not well known, but the main brands have versions of their models capable of running on these alternative fuels. The shift towards electric motors and those powered by Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG), which are more popular among alternative fuels for vehicles, means they are not very common and their use is very limited, although they remain very practical for reducing polluting gas emissions.

It is fairly common to find these types of fuel in urban public transport vehicles such as buses, one of the segments where they are most widely used to curb pollution in cities.