Future liquefied propane gas (LPG) vehicles could run on fuel derived from algae, according to researchers involved in a four-year €3.7m (£3.1m) EU-funded project.
The Directfuel consortium, which involves eight academic and industrial partners from Europe and one from the US, aims to genetically modify algae using special enzymes so that it emits propane gas. The gas would then be collected and compressed through the normal propane-processing procedure, turning it into its liquid form. This could be used for filling up the tanks of any LPG vehicle.
Dr David Leys, a biologist from Manchester University, a project participant, explained that no organisms − including algae − emit propane naturally.
But with the addition of enzymes, their behaviour will change. Leys compared the phenomena to the way bananas use ethylene to ripen fruit.
One of the advantages of the Directfuel technology is that the algae would be grown in industrial bioreactors exposed to sunlight, so it would not compete for space with food crops on agricultural land − unlike most biofuels.
Another difference is that the algae never needs to be harvested. The only thing fuel producers need is the gas emitted from the reactor.
Principal investigator Patrik Jones, from Finnish university Turun Yliopisto, said that this is more of a direct process compared with the steps involved in conventional biofuel production.
‘You have the potential to have very high efficiencies, but it’s theoretical at the moment,’ he added.
When compared with fuels such as petrol and diesel, LPG is viewed as a more environmentally friendly alternative because it contains less carbon and produces fewer harmful emissions.
LPG is currently used as a transport fuel in more than 13 million vehicles worldwide, according to UK LPG − the British trade association for the LPG industry.
It estimated that there are more than seven million LPG vehicles in Europe and approximately 150,000 on UK roads. However, it noted that the UK market is predominantly cars and light commercial vehicles up to 3.5 tonnes.
Most petrol-driven vehicles can be converted to run on LPG.
By the end of the project in four years, Leys said the group hopes to demonstrate a working prototype photobioreactor of approximately 300 litres in size. The reactor is being developed by Directfuel partner Photon Systems Instruments in the Czech Republic.
‘There could be cars driving on the road with propane from algae in about 10 years time,’ he said.