Green motoring: Numerous public transportation systems are moving toward hydrogen-powered engines as an alternative to gasoline, but most hydrogen today is generated from non-renewable fossil fuels such as natural gas.
Credit: iStockphoto
CHICAGO: A new method of producing hydrogen gas from biodegradable organic material has been developed, potentially providing an abundant source of clean-burning fuel.
The technology offers a way to cheaply and efficiently generate hydrogen from readily available and renewable biomass such as cellulose or glucose, and could be used for powering vehicles, making fertiliser and treating drinking water.
Public transport systems
Numerous public transportation systems are moving toward hydrogen-powered engines as an alternative to gasoline, but most hydrogen today is generated from non-renewable fossil fuels such as natural gas.
The new method developed by engineers at Pennsylvania State University in University Park, U.S., combines electron-generating bacteria and a small electrical charge in a microbial fuel cell to produce hydrogen gas.
Microbial fuel cells work through the action of bacteria, which can pass electrons to an anode. The electrons flow from the anode through a wire to the cathode producing an electric current. In the process, the bacteria consume organic matter in the biomass material. An external jolt of electricity helps generate hydrogen gas at the cathode.
In the past, the process, which is known as electrohydrogenesis, has had poor efficiency rates and low hydrogen yields. But environmental engineers Shaoan Cheng and Bruce Logan were able to get around these problems by chemically modifying elements of the reactor.
Economically viable now
Their study appears in the U.S. journal, the Proceedings of the National Academy of Sciences.
In laboratory experiments, their reactor generated hydrogen gas at nearly 99 per cent of the theoretical maximum yield using aetic acid, a common dead-end product of glucose fermentation.
"This process produces 288 per cent more energy in hydrogen than the electrical energy that is added in the process," said Logan.
The technology is economically viable now, which gives hydrogen an edge over another alternative biofuel, which is grabbing more headlines. "The energy focus is currently on ethanol as a fuel, but economical ethanol from cellulose is 10 years down the road," said Logan. "First you need to break cellulose down to sugars and then bacteria can convert them to ethanol."
One of the immediate applications for this technology is to supply the fuel for electric fuel cell vehicles – but it could also be used to convert wood chips into hydrogen to create fertiliser, said the researchers.
POP TEST
Can water in the liquid state be compressed?
I believe that's secondary school material too.
Glorious to have cheap'n'easy hydrogen fuel though.