You know what they say at the gym, “coffee can make us stronger.”
Well, guess what. Coffee doesn’t make only humans stronger; it does the same to concrete.
Australian engineers have found a way of making stronger concrete with roasted used-coffee grounds, which reduce the amount of coffee waste that goes to landfills.
According to lead author Dr Rajeev Roychand at RMIT University, the research team developed a method to make concrete 30% stronger by adding coffee waste. Firstly, they turn the waste into biochar, using a low-energy process without oxygen at 350 degrees Celsius.
“The disposal of organic waste poses an environmental challenge as it emits large amounts of greenhouse gases including methane and carbon dioxide, which contribute to climate change,” Roychand said.
Per the study, we generate about 10 billion kg of spent coffee globally per year. In Australia only, there are around 75 million kilograms of ground coffee waste every year, which mostly goes to landfills.
The study, published in the Journal of Cleaner Production, is the first to prove that waste coffee grounds can be used to improve concrete.
Roychand further explained, “The inspiration for our work was to find an innovative way of using the large amounts of coffee waste in construction projects rather than going to landfills—to give coffee a ‘double shot’ at life.
“Several councils that are battling with the disposal of organic waste have shown interest in our work. They have already engaged us for their upcoming infrastructure projects incorporating pyrolyzed forms of different organic wastes.”
Will this finding change the construction industry?
Joint lead author Dr Shannon Kilmartin-Lynch at RMIT said that construction industries around the world could play a role in transforming this waste into a valuable resource.
Kilmartin-Lynch said, “Inspiration for my research, from an Indigenous perspective, involves Caring for Country, ensuring there’s a sustainable life cycle for all materials and avoiding things going into landfill to minimize the impact on the environment.
“The concrete industry has the potential to contribute significantly to increasing the recycling of organic waste such as used coffee. Our research is in the early stages, but these exciting findings offer an innovative way to greatly reduce the amount of organic waste that goes to landfill.”
Professor Jie Li, the co-author and research team leader, added that coffee biochar can partly replace sand that the industry usually use to make concrete.
“The ongoing extraction of natural sand around the world—typically taken from riverbeds and banks—to meet the rapidly growing demands of the construction industry has a big impact on the environment,” Li said.
The co-author expressed concern over the sand, as 50 billion tons of natural sand are used in construction projects globally every year.
“There are critical and long-lasting challenges in maintaining a sustainable supply of sand due to the finite nature of resources and the environmental impacts of sand mining. With a circular-economy approach, we could keep organic waste out of landfill and also better preserve our natural resources like sand,” Li continued.
Alternatives for the construction sector
According to co-researcher Dr Mohammad Saberian, the construction industry should explore alternative raw materials to ensure its sustainability.
“Our research team has gained extensive experience in developing highly optimized biochars from different organic wastes, including wood biochar, food-waste biochar, agricultural waste biochar, and municipal solid-waste biochar, for concrete applications,” Saberian said.
It’s unknown as to when we can get this coffee concrete commercially, but the researchers have planned to develop practical implementation strategies and work towards field trials.
We still don’t know the researchers’ plans to develop their findings either, but the team is keen to collaborate with various industries to do it in the future.
Other innovative uses of waste coffee
Again, we’re reminded of how waste from coffee can be turned into something bigger—some time ago, we learned that coffee husk could be turned into a housing material.
In the spirit of celebrating coffee and the use of its waste, here are two more innovative uses of the waste.
Glasse frame from spent coffee grounds
Petar Stefanovski and Nikola Vuchkov came up with this unique idea to create a sustainable solution for used coffee grounds. Both were declared winners for their idea among the third generation of young people within a project called Regional Incubator for Social Entrepreneurs (RISE).
While many people have used coffee grounds for many different purposes for a long time, like using them as a natural fertilizer or natural scrub, Stefanovski and Vuchkov—as coffee friends—were moved to create a more sustainable coffee consumption.
“After research that has been done by UNDP, we found out that a big amount of organic waste is generated by coffee shops, restaurants, and bars,” the friends stated. “We as a social enterprise Coffee Mates are focusing on creating new innovative products on the market such as organic plant fertilizer and eyeglasses frames made of actual coffee waste.”
To create eyeglass frames, coffee grounds are mixed with biomaterials and molded into the desired shape. This process results in a material that’s durable, lightweight, and eco-friendly.
The coffee friends then asked Igor Joškovski, an artist and craftsman, to design and create the prototype for eyeglasses frames. “His experience in crafts is helping us to develop our product,” the friends stated about Joškovski.
As a result, the project ends with eyeglasses made from recycled materials, which could be customized to the customers’ needs and requirements.
Looking ahead, Stefanovski and Vuchkov have planned to collaborate with local coffee shops to help them continue with their efforts to create a circular economy for coffee.
Plastic film from coffee waste
We’ve seen plastic film made from crustaceans. This one’s different: a company called Aimplas has produced a plastic film from used coffee grounds, turning waste into a source of high-value products.
Nuria López the project’s principal investigator at Aimplas said that this innovation is a clear example of how biowaste can play an important role in the transition towards a circular economy.
Through avoiding biowaste generation and harnessing its potential as valuable secondary resources, industries can achieve sustainability.
López said, “In our case, we’re transforming coffee waste into plastic film for packaging. Meanwhile, other project partners, such as SAV – Agricultores de la Vega de Valencia, are project coordinating partners responsible for recovering waste to produce food additives, feed and oils for the food and cosmetic industries.”
To make the film, the company first obtained polyhydroxyalkanoates (PHA) from coffee grounds collected by Bio-Bean (United Kingdom). The investigators then formulated the PHA so they could process it by extrusion, and then they manufactured the film which be used in different types of flexible packaging.
There’s no information about the continuity of this EU-funded project, but let’s hope that we can get to enjoy another waste-sourced plastic alternative soon.
Sources
https://techxplore.com/news/2023-08-coffee-grounds-boost-concrete.html
https://www.aimplas.net/blog/aimplas-produces-plastic-film-from-coffee-waste/
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