A low-cost technique of converting the by-products of brewing into renewable fuel has been developed by a researcher at Queen's University, Belfast. .
The new method uses leftover barley from alcohol breweries which is converted into carbon. It could be used as a renewable fuel to heat homes, as charcoal for barbecues or as water filters in developing countries.
According to Queen’s, breweries in the EU throw out around 3.4 million tons of unspent grain every year.
Dr Ahmed Osman, from the university's school of chemistry and chemical engineering, was able to create enough activated carbon from just one kilogramme of grain to spread across 100 football pitches. His results have been published in the Journal of Chemical Technology and Biotechnology.
‘Novel approach’
“There are only a few steps in our low cost and novel approach – drying the grain out and a two-stage chemical and heat treatment using phosphoric acid and then a potassium hydroxide wash, both of which are very low cost chemical solutions,” said Dr Osman. “This then leaves us with activated carbon and carbon nanotubes – high value materials which are very much in demand.
“Liquid forms of carbon are normally shipped to the UK from the Middle East, and solid biocarbon, in the form of wood pellets is shipped from the US and elsewhere.
“Using this new technique, we can utilise more locally produced resources, reduce emissions linked with the agriculture sector, and we are also creating a high-value product,” he said.
“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. 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.”
He said the “synthesis of value-added products from barley waste” was a “prime example of the circular economy, by taking waste food by-products and creating a high-value product. It has benefits to the environment and society through economic and social opportunities.”
