Coffee waste gets a second life as stronger, low-emission bricks in Australia

Swinburne's Dr Yat Wong firing bricks made from coffee waste. Swinburne University

Australian researchers at Swinburne University of Technology have developed strong, sustainable bricks made from used coffee grounds—offering a potential breakthrough in reducing construction’s carbon footprint.

On June 27, the university announced signing an IP licensing deal with Green Brick to launch these sustainable bricks.

“For the last century, materials have been judged by one thing: cost per square meter, but in the next chapter, we’ll judge them by carbon, transparency, and circularity. And those metrics favor a new product,” said Philip Ng, Green Brick’s founder.

Brewing a cleaner brick

An estimated nine million tonnes of ground coffee are used globally each year.

This consumption results in approximately 18 million tonnes of wet spent coffee grounds (SCGs) generated as a byproduct.

The growing organic waste presents an environmental challenge. Most of that spent coffee is in landfills, creating methane – a greenhouse gas.

Over 1.3 million cups in Australia alone are sold daily, leading to about 10,000 tonnes of coffee waste yearly. And it adds to the nation’s carbon footprint.

That’s why a team led by Dr. Yat Wong from the university decided to find a way to use this discarded waste.

While past efforts have seen coffee waste transformed into biochar for concrete, like a footpath in Pakenham, Victoria, and even processed into coffee oil by a UK-based Bio-bean, Dr. Wong’s team has found a new purpose.

The researchers used coffee waste from cafes and restaurants in this new work.

The coffee waste was blended with clay and incorporated with an alkali activator to create their low-emission bricks.

This specific formulation is key, enabling the bricks to be baked at 200 degrees Celsius (360°F), i.e., 80 percent less than the temperatures required for conventional brick firing.

“It’s lighter on energy, faster to produce, and designed to reduce electricity-related CO₂ emissions by up to 80 percent per unit,” Dr. Wong said.

Tougher than your average brick

The new method for brick production drastically reduces the environmental impact typically associated with standard, energy-intensive manufacturing that relies on fossil fuels.

An earlier study pointed out that a single kilogram of brick produced using coal firing generates approximately 64.26 grams of CO2 emissions.

What’s more, these sustainable bricks are said to be remarkably durable, doubling “the Australian minimum standard for strength.”

The team says the project delivers a powerful dual benefit: it diverts massive amounts of coffee waste from landfills, reducing methane emissions and creating a low-carbon, high-performance building material.

Meanwhile, the quest for sustainable brick production extends beyond coffee grounds.

For example, in 2024, architecture studio Grimshaw, in partnership with the University of East London (UEL), developed “Sugarcrete.” This innovative brick is made from bagasse, a byproduct of sugarcane.

Bricks produce 15 to 20 percent of the carbon emissions of traditional bricks. Moreover, its carbon footprint is 20 times smaller and four to five times lighter than traditional concrete.

It is exciting to see researchers worldwide develop innovative, sustainable building solutions, leveraging everything from spent coffee to sugarcane waste. What could be the next sustainable option?

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