Keen cleantech observers will have heard of the “artificial leaf” – MIT researcher Daniel Nocera’s potentially disruptive energy storage technology that, through a supercharged photosynthesis-like process, uses sunlight to split water into hydrogen and oxygen and then stores the emitted gases in a fuel cell.
But what about the “electric leaf”? In another twist on photosynthesis, but coming from a completely different direction from the MIT team, Scottish scientists have devised what they say is a more efficient way to make biofuels, using electricity instead of sunlight.
The Financial Times reports that the team from the Glasgow Solar Fuels project at Scotland’s Glasgow University have created an “electric leaf” based on photosynthetic bacteria, but whose biochemistry has been altered by radical genetic engineering to produce a liquid hydrocarbon not unlike petrol. And while this might not sound so different from the various other research efforts around the world seeking to use bacteria or algae to create biofuels on a commerical scale, the Glasgow technology breaks from the pack on a fundamental point: instead of using direct sunlight, the energy input will be electricity, generated from renewable sources like wind or solar.
“The problem with photosynthesis is that it is extremely inefficient – its maximum efficiency [for turning solar energy into biomass] is 4 per cent and in most plants it is about 0.5 per cent,” said project head Professor Cogdell, speaking at the American Association for the Advancement of Science annual meeting in Vancouver last week. “We think we can do much better by taking electricity from a renewable source and using that to drive the reaction.”
To achieve this, the team will use extensively re-engineered blue-green algae, or cyanobacteria, altered to produce a liquid hydrocarbon-based fuel similar to petrol (terpenes) that would require little or no refining. The algae would also be engineered to create electrically conducting filaments known as pili, that would connect the cyanobacteria to a renewable power supply.
Quoted in the FT, Cogdell described the project’s backers – the UK Biotechnology and Biological Sciences Research Council and the Engineering and Physical Sciences Research Council – as “very brave” – while the chemical and biological principles underpinning the technology are well understood by the team, a fully functioning “electric leaf” is still several years (and more research) off being realised.
But, he added, the return on the £3 million grant stands to be enormous if the project is successful, considering the fact that “one of the grand challenges that mankind faces is to make dense, portable fuels for transport from non-carbon sources.” So watch this space; according to the Financial Times, Cogdell estimates that the Glasgow team could have a small demonstration system working within five years.
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