Making fuel out of thin air
cnnLimitless Carbon-Neutral Hydrogen With A Little Help From Our Bacteria Friends
Wouldn't it be great if you could simply grab carbon dioxide from the air and turn it back into fuel?
According to Germany-based renewable energy start-up Sunfire, you can.
"In fact, the idea has been around since at least the 70s," says Christian von Olshausen, the company's Chief Technology Officer. But the process is expensive. "For as long as fossil fuels have been cheap and readily available, there's not been sufficient demand," he adds.
Now -- with the world's finite stock of crude oil on the wane, and amidst pressure to reduce global carbon dioxide (C02) emissions -- the idea of converting those very carbons back into what Olshausen calls "synthetic fuels" is becoming more financially viable.
"The combustion of synthetic fuel does not increase the amount of C02 in the atmosphere," he explains. "This is because the carbon is being continuously recycled."
So, why waste hard-won green electricity to produce old-fashioned petrol?
Dr. Jeff Hardy is head of the UK's National Energy Research Network (NERN). He says that, while all efforts should be made to reduce our dependence on liquid fuels, it may not be possible for some industries:
"The thing with fuel is that it offers very high density energy storage ... for areas like long haul aviation, it's hard to see what could replace it."
"This is going to be a long process," admits Olshausen. "I'd estimate that it will take between one to two decades before we can replace a single digit percent of current demand (for fuel)."
The problem, he says, is developing materials that can resist extraordinarily high temperatures for long periods of time without degrading.
"But we'll do it," insists Olshausen. "Many innovations in the past century, like the car or the computer, have had to overcome seemingly impossible thermodynamic obstacles."
Of course, producing more than tiny amounts of hydrogen for commercial purposes requires a slightly larger-scale process. Hydrogen, of course, is the foundation of the “hydrogen economy” that has been promised to the world for decades now as the solution for copious amounts of cheap, clean energy. Perhaps the promise is finally in the early stages of being fulfilled: it’s only lately that hydrogen fuel cell products have begun entering the commercial marketplace at a rapid clip. Fuel cells are showing up in everything from low-emissions cars (hydrogen has more efficient energy density than the batteries typically used in electric cars, which make fuel cell cars more efficient and cleaner than electric vehicles) to data centers (in the form of Bloom Energy’s pricey but marvelous “Bloom Boxes”) to commercial phone-charging products such as Horizon Fuel Cell’s MiniPAK home fuel cell device.
The problems is (let’s go back to that high school physics experiment for a moment) that pesky bit of current required to create the hydrogen must come from an external energy source – a battery or the electric grid – which means that currently, hydrogen is merely an energy carrier and not an actual energy source. Even with the cheapest and most efficient hydrogen creation process today – still hydrolysis of water – it requires more energy to make the hydrogen than the hydrogen itself supplies. So how can it be a clean, cheap source of renewable energy if you still need electricity from toxic batteries or dirty fossil-fuel-fired plants to create the hydrogen? (In the same way people view electric cars as being carbon-neutral, forgetting that the car must be charged by plugging it into an electric source that inevitably ties into a grid powered by coal or oil burning.)
The answer is: hydrogen can’t be a carbon-neutral source of energy with status quo technology. Not yet.
Researchers at Penn State University, however, may have taken a few recent steps toward solving the problem by using – of all things – bacteria. (Though entering a new, modern “Bacteria Economy” just doesn’t have quite the same sexy ring to it.) Via the new process, scientists have been able to create hydrogen from scratch, in a carbon-neutral way, minus any input from grid electricity or batteries and minus any output of greenhouse gasses.
The new process, which uses something called microbial electrolysis cells (MECs), could ultimately produce fuel cells that are essentially self-powered and therefore limitless in their ability to produce clean, carbon-neutral and emissions-free energy, reported the BBC.