Turning straw – or indeed any other agricultural residue – into fuel for your car is a neat trick, being perfected in Denmark.
A factory in Kalundborg is producing second generation biofuels, meaning crucially no food crops are used in the process.
“We’re demonstrating to the world, but most particularly to customers, that this technology actually works, that you can take a bale of straw, and make that into ethanol,” says Michael Persson, Vice President for Corporate Affairs at Inbicon, the company behind the project.
“What we do is we take straw, which is a residue, an agricultural residue, we cook it under pressure, and we let it undergo an enzymatic treatment, we ferment it and we distill it.
“And from that process we will have ethanol, which can replace petrol in cars, we will have lignin, which can replace coal in power plants, and we will have a C5 molasses, that can be used as a feed or as a booster for biogas production.”
The factory should produce up to 5.5 million litres of fuel-grade bio-ethanol per year. Getting to that level is a big challenge.
“When working with new technologies like these it is always fairly easy to do it in a laboratory. The difficult part is to upscale it on an industrial scale in industrial conditions like we do here,” admits Persson.
The plant is at the centre of a European Union project, with researchers focusing on squeezing every last drop of energy from the straw.“One of the partners is a Dutch company, DSM, whch has a technology to convert the molasses into ethanol – this means that we can increase the ethanol output from the same amount of straw,” Persson explains.
The ethanol produced in Kalundborg is blended with petrol and sold around Scandinavia.
But what interests Inbicon is selling its biofuel production technology, rather than the output.
“The next step is to find a place where we can build, or where somebody will build a commercial-scale plant, because this is a demonstration plant, but a real commercial scale plant would be five to ten times as big as this one,” says Persson.
Given that the technology can be adapted to work with pretty much any kind of agricultural residue, Persson hopes one day to see plants springing up all over the world.