Environment

Process converts unloved brewery waste into high-value charcoal

Process converts unloved brewe...
Spent brewery grain is typically composted, or sometimes used in animal feed
Spent brewery grain is typically composted, or sometimes used in animal feed
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Spent brewery grain is typically composted, or sometimes used in animal feed
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Spent brewery grain is typically composted, or sometimes used in animal feed

According to Queen's University Belfast, breweries in the European Union dispose of about 3.4 million tons (3.084 million tonnes) of spent barley grain every year. That could be about to change, though, as scientists at the university have created a method of converting that waste into useful charcoal.

Led by Dr. Ahmed Osman, the researchers devised a process that begins with the grain getting dried out. A two-stage chemical and heat treatment follows, which utilizes phosphoric acid and then a potassium hydroxide wash – both chemicals are quite inexpensive.

What's left behind is activated charcoal, which could find use in applications such as heating fuel in homes, barbecue briquettes, or water filters. In lab tests, 1 kg (2.2 lb) of grain was sufficient to create enough carbon to cover "100 football pitches."

The technique can also be utilized to create carbon nanotubes, which – among other things – are being incorporated into better batteries, transistors, and even artificial muscles.

Ultimately, it is hoped that the technology could not only help keep spent grain from going to waste, but that it could also boost the local economy of regions where breweries are located.

"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," says Osman. "Using this new technique, we can utilize more locally-produced resources, reduce emissions linked with the agriculture sector, and we are also creating a high-value product."

The research is described in a paper that was recently published in the Journal of Chemical Technology and Biotechnology.

Source: Queen's University Belfast

5 comments
riczero-b
Good idea, but what are the costs of drying out the spent mash? Possibly use solar for this although maybe not in N. Ireland. If you had charcoal with residual acid and neutraliser it would be good for sewage treatment.
Leif Knutsen
Is the process using Green Energy in its production? Not any job, only Green Jobs can start to move the economies of the world out of the Climate Crisis morass. As long as capitalism has the ability to profit from polluting the commons, (the very foundation of violence IMO), every “Black” job just digs the hole deeper. Only green jobs ADD VALUE to the economy and start to rejuvenate Planetary life support systems as well as the economy via distributed green energy from the renewable sector. Only GREEN JOBS bring enlightenment to the populations of the world. Only green jobs should be subsidized. IMO, Preferably with a universal Medicare health policy and a ~$1200/month untaxed basic income. For those benefits, I propose a minimum of 32 hr/month environmental public service jobs. All extra entry-level Green jobs pay a minimum of $20/ hr with normal taxes applied. Bingo! Homelessness vanishes, 100% employment achieved, Universal Health Care paid for as the Planetary life support systems are healed inexpensively. Ample time and money are also now available to pursue higher education without going in debt for the remainder of your life. Cash-flow is returned to the communities, not to the bottomless pockets of the Pollution Profiteers and to off-shore tax shelters.
windykites
I would have thought that cattle food would be the ideal use. It is nutritious, and would need little processing (drying)
Bruce Anderson
I suppose using all that grain to make bread rather than beer is off the table. Some environmental purist must have proposed this.
ljaques
Yes, a cheap repeatable source of nanotubes would be good for the future. That's if the washing of the grain is eco-nomically/logically sensible. Barley bread? Cattle feed after nutrition gone? $20/hr green entry-level pay? Oy vay.