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Arthur Kay, Bio-bean founder
Arthur Kay, Bio-bean founder. Photograph: Roger Harris/Bio Bean
Arthur Kay, Bio-bean founder. Photograph: Roger Harris/Bio Bean

The innovators: how your coffee can light up your barbecue … and boiler

This article is more than 8 years old

The Bio-bean start-up recycles waste coffee grounds into biomass fuel pellets and coals that can fire up both boilers and BBQs

While the distinctive smell of a barbecue may herald the first sign of summer, it is not often associated with energy efficiency.

That may be about to change with the launch of a new type of barbecue coal called Hot Coffees, which hails from waste coffee grounds.

The bags of coals, expected to go on sale later this year in petrol station forecourts and homeware stores, are just the latest product from Bio-bean, a young London-based company which produces biofuels from coffee grounds.

The coals are produced at a 20,000 sq ft production plant in Cambridgeshire that takes in tonnes of waste coffee from the UK’s cafes and factories.

The fuels produced are the culmination of an idea by Bio-bean founder Arthur Kay. While studying architecture at university he became interested in circular economies, where resources are kept in use for as long as possible.

A Bio-bean recycling bin Photograph: from Bio Bean

While working on the design for a coffee shop, he started to focus on where the UK’s 500,000 tonnes a year of waste coffee ended up. In his research he found that oil could be extracted from waste coffee and turned into biodiesel with the leftover grounds turned into biomass pellets for use in boilers.

“You have a resource which is currently under-utilised, and is currently costing companies to get rid of it [through waste disposal],” says Kay, 25. “It is also a valuable resource. Coffee has a higher calorific value than wood for instance, so there is more energy contained in it than wood.”

When every espresso, americano or cappuccino is brewed, hot water passes through the ground beans extracting both the flavour and the caffeine. The leftover grounds are usually thrown out; but in the five-stage system used by Bio-bean, the grounds are refined, agitated and dried out. A biochemical process extracts the oil content, which constitutes about 20% of the weight, while the remainder is dried and made into pellets, briquettes – and later this year, into barbecue coals. It takes just a few hours after the grounds have been delivered to the factory before they become fuel, says Kay.

The pellets are packaged into 1 tonne bags and sold for use in biomass boilers, be they in family homes, airports, offices or supermarkets. A 1 tonne bag is enough to heat a family home for a year, says Kay. Although he refuses to reveal the price he admits they will be cheaper than wood pellets. Some customers supply their waste coffee to Bio-bean and then use the fuel to heat their premises, he adds: “It creates a closed loop system.”

Bio-bean BBQ coals recycled from coffee grounds Photograph: Bio Bean

The extracted oil is – known as second generation or advanced biofuel, because it derives from a waste product: coffee. Such biofuels have been used by McDonald’s – in its case sourced from cooking oil – to fuel its delivery trucks. The Bio-bean oil is blended with mineral diesel by fuel companies, says Kay.

Along with producing pellets and coals comes the challenge of collecting the grounds. Waste disposal trucks collect the grounds helping the cafe or shop save on disposal costs, he says. The providers range from a small chain of coffee shops to a large producer of coffee. At present the plant is churning through “tens of tonnes a day” but hopes to be processing hundreds of tonnes a day by the end of the year.

Kay says his interest is in creating a system which will displace conventional fuels and waste disposal methods. “It is not about replacing the cup, for example. It is about saying this is a better, cleaner and cheaper cup,” he says.

The number of biomass pellets produced in the UK (50,000 tonnes) is far outweighed by the number used (5m tonnes), says Kay. Most are imported from abroad, predominantly from the US.

As for the barbecue coals, they are heading to market later this year. Kay says they will reach cooking temperature faster than charcoal, and that they will be cheaper.

And the smell? Beyond a faint aroma, there will be no smell of coffee, he pledges.

You can read our archive of The innovators columns here or on the Big Innovation Centre website where you will find more information on how Big Innovation Centre supports innovative enterprise in Britain and globally.

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