It could be the ultimate in green energy, biofuel produced using solar energy.
Now scientists from two of Scotland’s leading universities have been given more than £1.1million to make it become a reality, and a potential money-spinner for north and north-east businesses.
Robert Gordon University (RGU) experts Professor Linda Lawton and Prof Peter Robertson, alongside University of St Andrews Prof John Irvine, have been awarded funding of £1,153,133 by the Engineering and Physical Sciences Research Council (EPSRC) to investigate photocatalytic bioethanol production.
Over the next four years, the trio, who specialise in microbiology, engineering and chemistry respectively, have been tasked with designing a cost effective, environmentally friendly approach to producing bioethanol from agricultural, forestry or industrial waste products, using solar energy.
Rather than use up food crops such as sugar cane, the approach harnesses the substantial quantities of fibrous waste available within the UK such as straw or recovered paper, which consists largely of cellulose.
Sugar molecules are contained within the cellulose but are bound within a complex structure and require to be released before they can be fermented and turned into ethanol.
“Previous attempts to harness cellulosic waste have used extreme treatment conditions to release the usable sugars, with enzymes, acid and alkali explosion, wet oxidation and steam explosion being combined with high pressures and temperatures,” said Prof Lawton.
“These procedures are expensive, energy demanding and generate hazardous waste. What we are proposing is the production of bioethanol using photocatalysis combined with the fermentation process in a single reactor. Photocatalysis, the use of a catalyst to accelerate a photoreaction by generating free radicals, will release sugars from the cellulose which will then pass through a semi-permeable membrane before being fermented to yield bioethanol.”
The approach has multiple advantages, according to the research team, using a catalyst which is low cost, non-toxic, self-cleaning, recoverable and activated by harvested natural light. Prof Robertson said: “One of the greatest challenges in the 21st century is to meet the global energy demand, with an increasing focus on renewable energy sources.
“Biofuel production involving food crops has been criticised due to a rapidly increasing population, food prices and the necessity of deforestation for their cultivation, so there is an urgent need to develop more sustainable alternatives. This is about taking something that is a waste product and converting it into something we can utilise.”