How is biodiesel made ?

Biodiesel is made by causing a chemical reaction within a number of different products to produce viable oil. The process was first tried in the middle of the 19 th century and these days is widely carried out in biodiesel plants across the world. While this commercial method of making biodiesel is carried out on a large scale more people are turning to small scale processing of waste materials to produce their own fuels.

It is entirely feasible to produce biodiesel on a small scale, and there are simple steps that can be followed to make it happen. To produce the fuel you do need an alcohol substance, and many people use widely available methanol. You will also need an alkaline catalyst and the commonly used are Sodium or Potassium Hydroxide. By treating all the ingredients in the following steps the chemical reaction which occurs produces biodiesel. The steps assume knowledge of chemistry to some extent:

•  Filter the waste oil for impurities and remove any water contamination;

•  Separate the methyl esters from the glycerol product;

•  Leave the remainder to settle, and the fuel and glycerine will form separate layers;

•  Separate the fuel from the glycerine layer;

•  Filter the fuel to five microns;

•  Once obtained and filtered, leave to dry and you have biodiesel!

Of course this is a basic explanation and to carry out the steps correctly you need to know the correct quantities of each, but the basic premise is the creation of the chemical reaction that produces the biodiesel.

What is biodiesel used for ?

Biodiesel is increasingly used on a commercial scale to power vehicles, but it is important to understand that 100% biodiesel is not a suitable straight replacement for commercially available petro-diesel. Instead the two need to be mixed, and most engine manufacturers will only warrant their products to use up to 20% biodiesel mix. Some will not even warrant the use of the fuel, but this is set to change as more research into the production of bio fuels is carried out.

With demand soaring it is little surprise that biodiesel plants are being built across the world and most production of the fuel comes from within Europe. However, rather than using waste materials as in our simple explanation above these plants raise their own crops – usually rapeseed or soya – in order to produce the fuel. This has led to some controversy yet is a viable method of subsidising our remaining fossil fuel supplies.

Trains can run on biodiesel and in the UK there are many examples of railway companies using such fuel to power their fleet. Lorries are also being converted to biodiesel on a more regular basis too. Where cars are concerned manufacturers are investigating the development of biodiesel specific engines, and as the fuel itself is known to have greater lubricating qualities than standard diesel this is surely the way forward.