Straw men

From oilseed rape, corn and sugar beet, to jatropha, used cooking oil and pond algae, the list gets longer every year. In the UK, the latest matter to be added to the list is straw.Researchers at the plant research division of Warwick University, the Warwick HRI, are working on ways to turn wheat straw into biofuel, using a combination of bacteria and fungi, such as mushrooms. The conversion process can either take place on farms themselves or in larger, off-site industrial bioconverters.

Sophisticated
Dr. Kerry Burton, research team leader at Warwick HRI, says that, “the fungi and bacteria break down the straw harshly into various chemicals which we can then convert into either bioethanol or other bio-chemicals. At the moment, we use fairly small bioconverters, but we are experimenting with more sophisticated techniques, like a 300 litre experimental fermenter for the bioconversion of liquid from straw.”

Mushroom expert
Burton’s colleague – and mushroom expert – Dr. Dan Eastwood, explains that a key focus of the research is to learn more about how the fungi actually grow on the straw and break it down.

“We need to be able to retain as much energy in the fuel source as possible, rather than the fungi using it as part of its own growing process. By understanding that more, we can refine the whole process so it needs as little energy input as possible in order to get the best results,” says Eastwood.

Hungry
If the process does get to the commercial stage – Burton estimates that could take five to ten years – there would certainly be no shortage of straw. The UK produces around twenty million tonnes of the stuff every year. That’s one third of a tonne for everyone in the country.

However, it isn’t hard to imagine arguments ensuing about farm animals going hungry because their straw is being diverted into biofuel production.