Spent Grain From Breweries Could be Repurposed as Fuel

Leftover grain from breweries, which might otherwise end up in landfills, could be used to heat your home.

Researchers from the UK have created an inexpensive, environmentally friendly technique that converts barley into a renewable energy. Their work, published in the Journal of Chemical Technology and Biotechnology, shows that two chemicals (phosphoric acid and potassium hydroxide), could be used to transform grain into carbon used for fuel.

Breweries boil vast amounts of barley to make beer, and is then disposed of in different ways. Some brewers are able to sell that grain to farmers as feed for livestock. But a lot also ends up being dumped in landfills. Researchers estimate that, in the EU alone, breweries waste 3.4 million tons of grain each year.

One kilogram of grain could produce enough activated carbon to span across 100 soccer fields, they say.

Dr Ahmed Osman, lead author of the study, said this new technique creates an opportunity to utilize locally produced resources while also reducing emissions.

“Across the globe, there is a real demand for carbon as it is used to create fuel for households, parts for water filters and charcoal for barbecues,” he said.

The approach involves drying the grain out before treating it with the two chemicals. Osman said both phosphoric acid and potassium hydroxide are low-cost solutions. Researchers are left with activated carbon and carbon nanotubes—high-value materials that have been in demand within the energy sector.

“If we are able to take something that would otherwise be a waste and turn it into a useful biofuel, it can only be a good thing for our planet. It could really help to solve global waste and energy problems,” Osman said.

Researchers say they’re now exploring ways that this method can be commercialized.