Credit: TCD (The cool down)
“This can lead to improved strength development, reduced micro-cracking, and enhanced overall durability.”
While you may have thought about the harmful environmental effects of your morning coffee when served in a single-use, throwaway cup, there’s another aspect of your daily caffeine boost that might be causing global warming emissions.
According to the United States Environmental Protection Agency, spent coffee grounds disposed of in landfills, like all decomposing organic waste, release methane gas, which is up to 25 times worse than carbon dioxide at trapping heat in the atmosphere.
But what if those coffee grounds could be used for a purpose and solve another problem at the same time?
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.
Turning coffee waste into concrete!
Researcher Dr Rajeev Roychand and his team at @RMIT have brewed up an ingenious solution: using roasted coffee grounds to strengthen concrete by 30%.
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.”
Consider how the used coffee grounds may someday be used to construct your next favourite coffee shop the next time you purchase a cup of joe.