While you’ve perhaps considered the negative environmental impact of your morning coffee when given a disposable, single-use cup, there’s another element of your daily caffeine boost that may be contributing to planet-warming gases.
Like all decomposing organic matter, used coffee grounds that end up in landfills produce methane gas, which is up to 25 times worse than carbon dioxide in terms of trapping heat in the atmosphere, according to the United States Environmental Protection Agency.
But what if those coffee grounds could be used for a purpose and solve another problem at the same time?
Turning coffee ☕ waste into concrete! 🏗️— Philip Green OAM (@AusHCIndia) September 11, 2023
Researcher Dr Rajeev Roychand and his team at @RMIT have brewed up an ingenious solution: using roasted coffee grounds to strengthen concrete 🧱by 30%. More about their innovation and future plans 👇🔗 https://t.co/FSlDwksuen pic.twitter.com/IDOs8CnH7i
According to Anthropocene, researchers in Australia have been adding coffee grounds to concrete, utilizing a process called pyrolysis that turns them into a carbon-rich biochar that can reinforce the building material.
Not only do the processed coffee grounds make concrete 30% stronger, it also provides a sustainable alternative to mined sand, which is typically used when concrete is mixed. As Anthropocene notes, “This would be a rare double-win for the environment.”
Rajeev Roychand, a materials scientist at RMIT University in Australia, said the approach delivers a “closed-loop circular economy” and removes the need for a “finite natural resource” like sand to be an essential ingredient in a world where construction demands are increasing.
“The pores within biochar absorb and retain water, serving as micro reservoirs, which can then be released slowly into the surrounding concrete matrix, aiding in the hydration of cement particles,” Roychand told Anthropocene. “This can lead to improved strength development, reduced micro-cracking, and enhanced overall durability.”
With 75,000 tons of coffee grounds disposed of every year in Australia alone, the process will prevent the majority of that from ending up in a landfill site and address a resource problem all in one go.
The research suggested that swapping out just 15% of standard concrete mix with the pyrolyzed coffee grounds will help to use up all of the country’s coffee waste. Additionally, if the idea was used globally, it could save 1 million tons of coffee grounds from contributing to the production of harmful gases that exacerbate global heating.
“There is keen interest from local councils and the construction industry [in Melbourne],” Roychand added. “We are in consultation with a few councils who are keen to translate this research into the field applications for their upcoming projects.”
So next time you order a coffee, think about how the waste grounds could one day build your next favorite java joint.
Join our free newsletter for weekly updates on the coolest innovations improving our lives and saving our planet.