According to estimates, breweries discard approximately 3.4 million tonnes of leftover grain in the EU alone, constituting a massive waste of energy put into agricultural production, and potentially missing out on important opportunities.
One way to address this unfortunate fact would be to develop a process for converting unused barley from breweries into a renewably sourced carbon which could have countless applications both within households and industry.
As Dr. Ahmed Osman from the School of Chemistry and Chemical Engineering at Queen’s University Belfast has demonstrated in a paper out in the Journal of Chemical Technology and Biotechnology, just 1 kg of lignocellulosic biomass (or simply barley waste) could yield enough activated carbon to cover 100 football pitches.
“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. This then leaves us with activated carbon and carbon nanotubes – high value materials which are very much in demand,” said Osman.
The pitch here is basically three-fold – using locally sourced materials instead of importing liquid carbon and solid biocarbon from around the world, reducing agricultural emissions, and generating large amounts of a valuable product in the process.
“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,” Osman argues.
The research team emphasised that turning waste into high-value goods is a prime example of the circular economy which could not only aid in efforts to address climate change, but also create brand new economic and social opportunities for the people involved.
The work conducted at Queen’s University will be presented in a major conference Engineering the Energy Transition, set to take place between 26 and 28 February 2020.