Member Press Release - A circular economy solution using algae to create value from food and farm AD

A circular economy solution using algae to create value from food and farm AD waste

A group of pioneering anaerobic digestion (AD) plants in North West Europe are working with scientists to grow algae using nutrient rich digestate. The idea is to use the algae and it’s components as ingredients in animal feed, to optimise re-use of resources through the creation of high value products from waste.

The ALG-AD project, led by Swansea University in the UK, is looking to reuse nutrients from excess digestate – specifically nitrogen and phosphorous, and is working with 3 pilot AD plants across Europe to use this unwanted but nutrient rich digestate to grow algal biomass.

Each pilot AD facility works within a different environment - some are very rural, whilst some are predominantly urban – and each process different types of waste. The three facilities in Devon (UK), Brittany (FR) and Flanders (BE) will therefore represent an excellent demonstration of how the ALG-AD technology can be implemented in alternative real life conditions.

The researchers on this project are using photo bioreactors (PBRs) on each AD plant, and are working to develop the most efficient way or using digestate to grow algae in these PBR’s. The team is also looking at the best pairing of the type of organic waste being used against the growth of certain microalgae species.

Dr Claudio Fuentes Grünewald, the researcher leading this aspect of the project, said “Since 2018, the team have worked together to develop best practice guidelines on how best to filter the digestate, and how to use this to grow algae. There is great potential for algal products, and our aim is to share our expertise to enable a wider group of stakeholders to be able to expand this microalgae biotechnology into the AD field.”

Dr Phillippe Soudant, Research Director at CNRS (France) leads on the crucial downstream processing, where the raw algal biomass is transformed into alternative high value products.  He explained “There are so many potential valuable products in algae, such as peptides, lipids and proteins. We are analysing the different types of algae grown during this project to understand what the most interesting and valuable products might be for the animal feed sector”

Whilst the algal and AD sectors are not new, this project is testing an innovative technology which has raised some complex challenges. The fact that agricultural waste is being transformed, to then be utilised as animal feed, represents a grey area in terms of regulation, and introducing algae to the food chain is still a novel consideration.

Professor Carole Llewellyn, overall leader of the project, added: “INTERREG NWE has enabled us to bring an excellent partnership together with multidisciplinary expertise that is enabling us to tackle an issue on waste with demonstration at industrial AD facilities.

“Whilst the technology is still at a relatively early stage we are confident that using algae to clean up waste and produce valuable products provides a winning solution in the drive to create a circular economy.”

Photo Caption: l-r ALG-AD principle investigator Professor Carole Llewellyn, project manager Louise Hall and researcher Dr Claudio Fuentes Grünewald beside a  photobioreactor at Swansea University.




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The Interreg North-West Europe Programme fosters transnational cooperation to make North-western Europe a key economic player and an attractive place to work and live, with high levels of innovation, sustainability and cohesion. Find information about our funding opportunities and the positive changes our projects have brought to the territory and its people at


When reporting this story, please use Swansea University hyperlinks. Swansea University is a world-class, research-led, dual campus university offering a first class student experience and has one of the best employability rates of graduates in the UK.

Swansea is ranked 30th in the UK in The Times and Sunday Times Good University Guide. As well as achieving its UK top 30 position, Swansea was named runner-up for the overall University of the Year Title in the Good University Guide, and was also crowned Welsh University of the Year for the second time in three years.

The University has the highest possible rating for teaching – the Gold rating in the Teaching Excellence Framework (TEF) in 2018 and was commended for its high proportions of students achieving consistently outstanding outcomes.

Swansea climbed 14 places to 31st in the Guardian University Guide 2019, making us Wales’ top ranked university, with one of the best success rates of graduates gaining employment in the UK and the same overall satisfaction level as the Number 1 ranked university.

The 2014 Research Excellence Framework (REF) 2014 results saw Swansea make the ‘biggest leap among research-intensive institutions’ in the UK (Times Higher Education, December 2014) and achieved its ambition to be a top 30 research University, soaring up the league table to 26th in the UK.

The University was established in 1920 and was the first campus university in the UK. It currently offers around 350 undergraduate courses and 350 postgraduate courses to circa 20,000 undergraduate and postgraduate students. 

The University has ambitious expansion plans as it moves towards its centenary in 2020 and aims to continue to extend its global reach and realise its domestic and international potential.

Currently Swansea University have the biggest microalgae facilities (>22 tons) in the UK, running in three different sites (Devon, Port Talbot and Swansea).

Swansea University is a registered charity. No.1138342. Visit

For more information, please contact Catharine Jones ALG-AD press officer Tel: 7789 270041, or email:

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Tags: member press release, anaerobic digestion, food waste operators, financial incentives