Grounds for celebration? Just in case you weren’t already using old coffee grounds as compost or pest management for your garden…
…the team experimented with pyrolyzing the materials at 350 and 500 degrees C, then substituting them in for sand in 5, 10, 15 and 20 percentages (by volume) for standard concrete mixtures.
The team found that at 350 degrees is perfect temperature, producing a “29.3 percent enhancement in the compressive strength of the composite concrete blended with coffee biochar,” per the team’s study, published in the September issue of Journal of Cleaner Production. “In addition to reducing emissions and making a stronger concrete, we’re reducing the impact of continuous mining of natural resources like sand,” Dr. Roychand said.
Suddenly cities full of espresso machines have an entirely new construction supply chain model. The scientists claim they were trying to solve for waste and not just hoping to justify drinking 10 cups of coffee per day.
…inspiration for our work was to find an innovative way of using the large amounts of coffee waste…
And so they conclude 100% of the 75,000 tonnes of waste that coffee drinkers produced in Australia can become a source for structural concrete. Worldwide there’s allegedly upwards of 6 million tonnes available. That means plenty of room still for innovations like powering public transit or making milk and mushrooms.