Issue date: 25 October 2004

ISSUE DATE: 25/10/04

The University of the West of England is looking at the potential for running its fleet of vehicles on renewable fuels made out of used cooking oil from its catering operations. Dr Stuart Shales and Dr Alan Scragg from the Faculty of Applied Sciences have been experimenting with production of bio-diesel from recovered vegetable oil used for frying chips.

Dr Stuart Shales explains. “Bio-diesel is a replacement diesel which can be made from vegetable oils and animal fats. Untreated oils will burn in a similar way to fossil fuels and contain almost the same amount of energy, but plant and animal oils are thicker and more viscous than normal fuels and therefore cause problems in diesel engines. However, if the triglycerides, which are the main constituents of fats and oils, are broken down to glycerol and fatty acid esters the viscosity is greatly reduced while still retaining its energy content.

“We are some way off from being able to produce sufficient amounts of bio-diesel on site but the seed of an idea has been planted. In the long term, with the prospect of raw materials eventually becoming scarcer we will all need to move towards conserving fuel. One way of doing this is to produce oil by growing crops like rapeseed and blending this with used cooking oil to produce blended diesel.”

The bio-diesel produced by the UWE scientists is made by putting the oils though filtration to remove impurities and adding methanol and sodium hydroxide to produce bio-diesel.

The economics of diesel production are another advantage. Duty payable on bio-diesel is 20p per litre lower than that charged on ordinary diesel. Production of bio-diesel from virgin oil is uneconomic because of the cost of the starting material but if recovered oil is used it becomes immediately viable. Catering organisations like UWE’s catering facilities are in effect paying for removal of waste oil. For the university there would therefore be an immediate cost saving in waste oil disposal as well as a potential gain in fuel production.

Chris Abbott, Head of House Services at UWE, said, “This project is in its infancy but by no means impossible. Ultimately if we can reduce the cost of running our fleet, these benefits could be passed onto students through a reduction in bus fares or upgrades to current transport.”

Scientists from the Faculty are currently in discussion with farmers who are interested in building a small scale oil processing plant next to farmland where rapeseed is currently grown. Stuart Shales continues, “If we can eradicate the need to transport raw materials by processing oil on site this could prove invaluable for the environment as it reduces at least one journey in the process – that of raw material to plant. In addition to this I can see a future where small processing plants could fuel farming transport on a local basis thus bringing new small scale industrial potential for farmers.”


Editors note

Jpeg visual available from Jayne.Andrews@uwe.ac.uk

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