If you thought that used coffee grounds were only good for making washing-up messier, clogging drains or putting on your compost heap, think again. Paul Gander examines some of the end-uses for this high-volume resource.
At one time or another, we must all have spent longer or shorter periods staring into a cold cup of coffee. But it is unlikely that any such experience constituted an entrepreneurial ‘eureka’ moment for us.
Not so for architecture student Arthur Kay. His close encounter with a cooling Americano back in 2013 prompted him to look beyond the thin layer of oil coagulating on its surface and to research a theory that, if spent coffee grounds (SCG) contained oil, they could prove a valuable raw material for fuel.
This was the start of bio-bean, a UK company which Kay set up the same year. Nor is forging a dedicated recycling stream from this feedstock such a mad idea: the company estimates that the UK population alone drinks 95 million cups of coffee a day, generating some 500,000 tonnes of SCG.
“In our seven years since founding, we’ve launched coffee collection services across the UK, built the world’s first industrial-scale coffee recycling factory and have recycled over 19,000 tonnes of coffee grounds,” bio-bean marketing manager Jessica Folkerts tells us at F&FT. “We currently process around 7,000 tonnes of spent grounds annually, and are in the process of expanding our capacity to 16,000 tonnes.”
A burning ambition to cut CO2 emissions
The two main products from bio-bean are SCG-derived biomass pellets for industrial users and (since 2016) Coffee Logs, sold through consumer retail outlets. “Coffee Logs consist of 70% grounds and 30% sawdust, which helps the grounds bind together,” says Folkerts. “Our coffee pellets contain a starch binder, which is a by-product of the food industry.”
Among bio-bean’s larger customers, Coca-Cola-owned Costa Coffee has been recycling its SCG this way for almost four years. In a statement last summer, Costa said the partnership had allowed it to divert 37% by weight of all its waste from landfill, so saving 4,500 tonnes of CO2 emissions.
Logistics are key to bio-bean’s success. “In some cases, particularly for businesses with a nationwide network, coffee grounds are brought to us via a backhaul model,” Folkerts explains. When it comes to smaller independents, working with waste management companies means that the recycler can, for instance, harvest coffee waste from as many as 21 different outlets across the entire Stansted Airport site.
In some cases, there are alternatives to shipping coffee biomass large distances in order to reprocess it as a fuel. At its Joure plant in the Netherlands, Jacobs Douwe Egberts (JDE) has been drying its used grounds and then using them directly as fuel for a biomass boiler, rather than sending them to landfill. Over a three-year period, JDE claims to have avoided generating 14,000 tonnes of CO2, said to represent a saving of 70% on annual emissions.
But as in so many areas, alleged savings on CO2 emissions are a fiercely-contested battleground, when it comes to end-uses for SCG. So, bio-bean argues that, as well as creating an 80% saving on emissions in comparison with landfill, its technology is responsible for a 70% emissions saving when compared with anaerobic digestion.
This third-party assessment takes into account the entire cycle “through to the point Coffee Logs are burned, inclusive of road miles, processing, briquette manufacture and use,” says Folkerts.
At the UK’s Anaerobic Digestion and Bioresources Association (ADBA), policy and market analyst Dr Nick Primmer says he is “very sceptical of this bold claim”. He maintains that SCG yields relatively high volumes of biogas. “In fact, coffee grounds are particularly well-suited to anaerobic digestion, as they don’t require pre-treatment and are rich in lipids.”
Primmer concedes that, as is the case with anaerobic digestion, reprocessing into briquettes will prevent emissions from rotting waste, but he contends: “Anaerobic digestion is the most efficient means of processing organic waste, yielding the highest renewable energy output.” He adds that the UK’s Waste & Resources Action Programme (WRAP) has recommended anaerobic digestion to government as the optimal recycling process for all organic wastes.
Coffee grounds to coffee cups
Not all those recycling used coffee grounds obsess over carbon footprint. In Berlin, Germany, Kaffeeform has for the past five years been producing and selling a range of coffee cups all containing a 40% proportion of SCG. Head of communications Anika Paulus does not see this in terms of competing alternatives. “Each idea, initiative and solution to reuse so-called ‘waste materials’ is great,” she tells F&FT.
As a small, independent brand with just five employees, Kaffeeform has not yet stuck its toe in the water of lifecycle analysis (LCA).
“We work with selected partners that share our values, when it comes to retailers but also to corporate companies which want a branded version of our cups,” she says.
Paulus calculates that, in the five years of the company’s existence it has turned the waste from some 750,000 coffee shots (or around 14,250kg of grounds) into more than 150,000 cups. An additional five years or so went into the research and trials that preceded the setting up of the business, she explains.
“All of the content is plant-based and from recycled or renewable resources,” Paulus states. “As well as the coffee grounds, another main component is recycled wood chips, which also create the nice marbled surface, natural oils and cellulose fibres, all of it hardened with starch-based biopolymers.”
Nor is the recycling of SCG a purely Western European phenomenon. Across the globe, businesses which have taken coffee-grounds as their principal raw material include Taiwan-based textile manufacturer Singtex, with its S.Café brand based on coffee fibres, and Ukrainian eyewear producer Ochis.
The list of end-products does not stop there. Back in London, bio-bean recently launched a natural flavour. “This is an aqueous natural coffee extract derived from food-grade SCG,” says Folkerts. “It has uses in a wide range of food and beverage applications.” She talks about a “unique, first-of-its-kind supply chain” for this product. “We take feedstock from a single source, and ensure the spent grounds remain in the food chain throughout the process.”
Meanwhile, bio-bean is also taking part in the EU’s Horizon 2020 WaysTUP! project, which aims to find ways of deriving higher value from urban biowaste, including coffee grounds. The project, which launched in October last year, will run until February 2023. As well as coffee, fish and meat waste, used cooking oils and other domestic biowaste will be collected in several European cities and provide the raw materials for producing a range of end products.
As the use of bioplastics (and in particular, biodegradable polymers) grows, we may see a drive to use SCG as a different type of feedstock. At the Brno University of Technology in the Czech Republic, a team has been exploring the use of coffee grounds as a valuable raw material in a number of applications.
Prof Adriana Kovalcik of the Department of Food Chemistry and Biotechnology says that her team’s approach is to use fractionation to obtain different components, such as oil, carbohydrates and lignin. “We are focused on the valorisation of SCG as a cheap carbon source for: the biosynthesis of polyhydroxyalkanoates (PHAs); as antioxidants and antibacterial substances; and as a cheap and biodegradable filler for large-scale bioplastics to improve their mechanical properties,” she tells F&FT.
PHAs are highly-prized and versatile biopolymers, but they can be expensive to biosynthesise. “The bacteria that produce PHA consume expensive carbon sources, such as glucose and fructose,” says Kovalcik. “Our team has shown that coffee oil or hydrolysates obtained from coffee grounds can serve as a significant low-cost carbon source for some PHA-producing bacteria.”
It is clear that these and other routes to ‘valorising’ used coffee grounds will only become more popular, as rising landfill charges make the ‘hole-in-the-ground’ alternative less and less attractive.