Bio-Bean Entrepreneur Arthur Kay Is Turning Coffee Into Fuel And Wants To Power All Of London's Buses

'Waste is whatever people want it to be.'

“I’m the most boring person to sit next to at dinner parties,” Arthur Kay jokes about his obsession with waste.

Specifically, he’s interested in coffee waste. The 25-year-old entrepreneur started a company that turns leftover coffee grounds from thousands of UK coffee shops into fuel to power homes, offices, airports, and factories.

His London-based company Bio-bean takes the grounds thrown away after making cappuccinos and flat whites, and processes them into bio-mass pellets which are mainly used for powering industrial boilers in large buildings.

Arthur Kay founded Bio-bean in 2013
Arthur Kay founded Bio-bean in 2013
Zhang Peng, Bio-bean

Coffee has a higher calorific value than wood, so releases more energy, he explains. The pellets are carbon neutral, as well as cheaper than many other forms of heating.

After just three years, Bio-bean is set to transform 10% of the country’s coffee waste – 50,000 tonnes – into energy this year. That will fuel 15,000 homes, the equivalent of “a small town,” Kay says.

Coffee grounds leftover from factories and shops
Coffee grounds leftover from factories and shops

In some ways, Kay – a coffee fanatic who drinks five to ten cups a day – doesn’t actually believe in the concept of waste.

“Waste is just a mentality, because the legal definition of waste is something that is discarded or thrown away,” he claims. “Waste is whatever people want it to be. If we stopped using gold for currency and jewellery and threw it away, it would be waste.”

Kay came up with the idea for Bio-bean as a young architect, working to design a coffee shop and factory in London. He noticed the huge bags of waste that piled up, and was driven to take action. “I get interested in quite strange things and it was fascinating realising how much of it there was. I’d never really thought about it.”

Coffee shops produce tonnes of waste.
Coffee shops produce tonnes of waste.
Joe Giddens/PA Archive

He learnt that coffee shops didn’t just produce a few hundred tonnes of grounds a year, but hundreds of thousands, at huge cost to the environment, as well as to the shops which pay to send the waste to landfill, generators or to break down naturally in a process known as anaerobic digestion.

But Kay doesn't think the coffee industry is particularly wasteful: “I don’t think it’s specific to coffee, I think coffee is getting quite a hard rap at the moment,” referring to the recent headlines that it is virtually impossible to recycle takeaway coffee cups. He points out that the same material is used in “all kinds” of other packaging.

“It’s just that coffee waste is a very emotive waste and product to be dealing with because it’s one that people often are very intimate with,” he reasons. “I guess it’s a low hanging fruit, a target for governments and journalists to look at.”

You could apply exactly the same treatment to a range of industries, such as fishing or brewing, he argues. Whisky and beer – whose bi-products often end up in landfill - have waste material with very “interesting compounds with interesting potential value to be massively beneficial to the environment”.

Ready-to-eat and ready-to-drink food products are something he also singles out: “A ready-to-drink coffee, ready to drink cocktail… the amount of packaging is phenomenal.”

The bio-mass pellets that Bio-bean creates.
The bio-mass pellets that Bio-bean creates.

In his own life, Kay claims he is eco-conscious, but “not in an impractical way”.

“I think the key thing when we talk about sustainability is that very, very few people want to compromise quality of life,” he explains.

“I’m not a vegan, I don’t wear a hair shirt, et cetera, but I do try and eat not too much meat and be conscious of where I buy food, and not driving and that sort of stuff.”

His logic is that people won’t buy eco-friendly products just because they are told to. “I don’t think it’s fair that people can be didactic. It’s about making sustainability the cheaper option and the better option in terms of quality of product, it’s not about saying you have to do it for an ethical reason.”

Despite his success, he feels like progress has been "quite slow,” he explains. Bio-bean has a lab in London and a factory in Cambridgeshire, He hopes for “a few more” in the next few years.

He points out that his company is the “exact opposite” of a classic start-ups based around software or mobile apps, which are relatively quick and inexpensive to set up.

The Bio-bean factory took years of research and development, and many millions of pounds of investment from investors including Shell and the Greater London Authority, and a prize of €500,000 from The Green Challenge, a global competition for eco-entrepreneurs. It was only finished in 2015, two years after he started the company.

“These are often things that are done by very, very big companies and often actually governments as well, so it’s really very capital intensive, and quite complicated in terms of engineering,” he says.

The Bio-bean factory in Cambridgeshire.
The Bio-bean factory in Cambridgeshire.

Though he can’t name which coffee shops he uses waste from, he confirms Bio-bean uses waste from “thousands” around country, and heats “supermarkets, offices, homes, airports and factories”.

“Now the dream has come true,” he adds: “we’re actually powering a coffee factory. It’s fantastic."

A waste management company collects the grounds on Bio-bean's behalf, charging a fee that is around 70% less than shops would usually pay to have it taken away.


Kay's transformed coffee is about to reach people in their homes too – this summer it will launch its first two products that you can buy in shops. One is a barbecue fuel (coffee ‘coal’) and the second is a coffee ‘log’ which can be used as “a winter fuel, heating your home in an open fire. Or outside in a chimney or something like that”.

Both will make clear they are sourced from your local coffee shop. “In the barbecue space specifically, the supply chain is very murky," Kay says. "A lot of it comes not just from forests but actually from the rainforests in South America as well,” Kay says.

The coal and logs will be sold in supermarkets, garden centres and petrol stations, and Kay hopes it will engage people with ideas of sustainability that are usually only talked about in distant, vague terms. No-one gets that excited about natural gas, he points out, and the same applies to the abstract idea of biofuel.

Kay has an answer ready for the killer question – does the coal smell like coffee when it burns? “Happily, or sadly, it doesn’t. It doesn’t have a particularly strong aroma. I kind of think if you know it’s coffee, you can tell, but it’s just got a kind of interesting smoky aroma.”

“I had a bunch of friends round at the weekend and we cooked on it and did make some tasty burgers and things. No-one’s dead, so that’s all good,” he jokes.

Beyond that, he has bigger dreams. Coffee grounds have a high oil content, and Bio-bean already removes the oil to make its pellet fuel. It has begun experimenting with this to make bio-diesel, a liquid fuel used for powering cars and jet engines.

Kay wants this to be the third product: “Our dream is to power London buses – you could power every bus in London, and one or two out of London, with London’s coffee grounds.”

'You could power every bus in London.'
'You could power every bus in London.'
Neil Hall / Reuters

He hopes that his work counteracts some of the bad press around biofuels – some types stoke controversy by being made from crops that could have been used for food. Most of the UK’s biofuel is pellets made from trees chopped down in America, which Kay claims is “actually bad for sustainability” and not cost effective.

But Bio-bean’s fuel is known as an advanced, or ‘second generation’ biofuel, and is made only from what would have been wasted.

Ultimately, Kay is calling for a change in mindset about what waste is. “Even the word waste is punitive, it’s got negative associations,” he claims. “So when I was designing that coffee shop, it’s about understanding that wasn’t actually a waste stream, it was just a resource. It was just frustratingly in the wrong place, in the coffee shop instead of in a factory or a car.”

He says he hopes to show more and more people that everything we throw away has value, in line with the proverb, ‘Where there’s muck, there’s brass’.

“It’s understanding that which is pretty exciting.”

The Postcode Lottery Green Challenge - which offers a €500,000 prize to individuals or companies who have business ideas to reduce CO2 emissions - is open until 1 June for entries.


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