New Multi-Problem Solving Use for Coffee Grounds Discovered by Scientists

The current global coffee industry generates approximately 10 billion kilograms of waste annually, with the majority ending up in landfills. However, a group of researchers from Australia have recently discovered that this waste can be put to a more sustainable use. By charring coffee grounds and incorporating them into concrete mixtures, they have found that it is possible to produce a version of the material that is 30 percent stronger than its traditional counterpart. 
 
This innovative method could potentially address several environmental issues simultaneously by reducing landfill waste and making productive use of organic materials. "Disposal of organic waste poses an environmental problem because it releases large amounts of greenhouse gases, including methane and carbon dioxide, which contribute to climate change," says RMIT University engineer Rajeev Roychand. 
 
As construction markets across the globe continue to expand rapidly, demand for concrete—a resource-intensive material—is also on the rise. This increased need has led to further environmental concerns as natural sand extraction from riverbeds and banks intensifies. 
 
"The continuous extraction...to meet the needs of the rapidly growing construction industry has a major impact on the environment," states Jie Li, another RMIT engineer. He continues by highlighting critical long-term issues related to maintaining sustainable sand supplies due to limited resources and significant ecological damage caused by sand mining operations. 
 
However, using coffee grounds in replacement for some proportion of sand not only helps manage organic waste but also aids in conserving these natural resources. 
 
Directly adding organic substances such as coffee ground into concrete would weaken its structural integrity due to chemical release; thus, scientists used minimal energy levels heating above 350 °C under the pyrolysis process, stripping oxygen off and creating biochar—porous carbon-rich charcoal forming bonds with the cement matrix hence incorporated within. 
 
Roychand’s team experimented with pyrolyzing at higher temperatures (500 °C) but concluded lower temperatures yielded stronger biochar particles. 
  
While initial results are promising, there's still work to be done. The team needs to evaluate the long-term durability of their innovative concrete product by testing its performance under various stressors, including freeze/thaw cycles and water absorption. 
 
In addition, they are exploring other organic waste sources like wood, food, and agricultural waste for creating biochar. "Our research is in the early stages," says Shannon Kilmartin-Lynch, an RMIT engineer on the project team. "But these exciting discoveries offer an innovative way to significantly reduce the amount of organic waste sent to landfills." 
 
The potential of this research extends beyond just reducing coffee waste; it could potentially revolutionize how we produce one of our most widely used construction materials, concrete. With more sustainable practices being adopted worldwide in a bid to combat climate change, innovations such as this could play a crucial role in shaping our future infrastructure development strategies while simultaneously addressing environmental concerns.