Coffee waste could be turned into electricity

Coffee waste could be turned into electricity

Polluting waste generated during coffee production has been turned into electricity for the first time, scientists have revealed.

The process of turning the raw material into the 145 million bags of coffee the world produces each year generates a huge amount of liquid waste which is highly damaging to the environment.

UK-funded scientists, working with Colombian researchers, have discovered a community of microbes in a wastewater treatment plant that could hold the key to degrading this coffee waste – generated during the washing of coffee beans and during the water-intensive process of making instant coffee.

The microbes eat the waste, producing energy which can be captured as a small electric current; enough to light a bulb. This type of device, called a microbial fuel cell, has not been used to treat coffee waste before.

Dr Claudio Avignone Rossa, a systems microbiologist at the University of Surrey, which led the project said: “We showed for the first time that it is possible to treat coffee waste using a microbial fuel cell. We feed the fuel cells with coffee waste, and most of the compounds that cannot be degraded naturally are degraded by the microbes inside.”

Funding for this research was provided primarily by UK Research and Innovation’s Biotechnology and Biological Sciences Research Council (BBSRC) and Engineering and Physical Sciences Research Council (EPSRC). Further funding from the British Council under the Newton Fund allowed the team to collaborate with Colombian researchers to demonstrate that coffee waste could be converted into electricity using a microbial fuel cell. Funding from EPSRC under the Global Challenges Research Fund then allowed the researchers to construct a small, inexpensive device suitable for use on Colombian farms.

The issue of waste from coffee production is particularly prominent in developing countries where the infrastructure does not always exist to process this waste and so it ends up in water courses, which become contaminated.

The new device could solve the problem by breaking down the polluting compounds in coffee waste so that it is no longer harmful to the environment. It is also simple and cheap enough that it can be built and installed on small, family-owned coffee farms in developing countries such as Colombia, the world’s third largest coffee producer. A cooperative of Colombian coffee farmers have already expressed an interest in using the devices, BBSRC has revealed.

“You can build one of these microbial fuel cells for only a few pounds, or even pennies, using materials that are just lying around, including ceramic tiles, terracotta slabs, kitchen foil and cardboard,” says Avignone Rossa, “and because they are very low cost and easy to construct, you can put several on every farm.”

As well as preventing environmental contamination, the microbial fuel cells could also help to relieve a huge strain on water supplies.

This project has been shortlisted for the 2018 Newton Prize – a £1 million prize fund, awarded to projects that demonstrate the best science and innovation in Newton partner countries.

The researchers hope that if their devices are used successfully in Colombia, they may be able to interest large coffee companies in Europe, where roughly one third of the world’s coffee is consumed, in adopting the same approach to treating their waste.

Energy and Clean Growth Minister Claire Perry said: “Your morning latte could start its life on a remote Colombian coffee farm and now thanks to UK Government funded research, those farms now have grounds to double up as producers of both coffee beans and electricity.

“Local growers getting extra buzz from their beans is a great example of seizing the industrial opportunities of moving to a greener and cleaner economy. At home our modern industrial strategy is helping the U.K.’s innovative clean growth sector brew up innovative technology like these fuel cells to deliver clean growth and build new markets across the globe.”

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Further information

The Newton Fund is managed by the UK Department for Business, Energy and Industrial Strategy, and delivered through seven UK delivery partners, which includes UK Research and Innovation (the seven research councils and Innovate UK), the UK academies, the British Council and the Met Office. Follow via Twitter: @NewtonFund.

The Global Challenges Research Fund (GCRF) is a £1.5 billion fund announced by the UK government to support cutting-edge research which addresses the problems faced by developing countries. The fund, administered through delivery partners including the research councils and national academies, addresses global challenges through disciplinary and interdisciplinary research, strengthens capability for research and innovation, within both UK and developing countries, and provides an agile response to emergencies and opportunities. For further information visit UK Research and Innovation: Global Challenges Research Fund and follow via Twitter: @GCRF.