It's fizzing, bubbling and fermenting in Groningen


Koen Gerlsma and Dennis Riemeijer, two interns from Hanze University of Applied Sciences, have been investigating residual flows from the catering industry and breweries in their project 'Groningen ferments' (Groningen gist). Do they contain enough useful substances for fermenting and producing green gas?

‘A fresh look at bottom-up sustainability’, believes Geert Greving, departing Head of Public Affairs at GasTerra, who is supervising the two interns.

GasTerra would like to do its bit for a sustainable future; by supporting Groningen ferments, for example. ‘We've set up this project together with the Hanze University of Applied Sciences and the municipality of Groningen’, explains Geert. ‘We're using it to investigate how we can make Groningen more sustainable and hence contribute towards a circular economy.’ He would like to set out why GasTerra finds such projects so important. ‘We have to be climate-neutral by 2050. We'd like to show what that means, in concrete terms, involving different stakeholders. In the past, a lot of money has been spent on the Dutch gas system. Of course, you can just write it off but wouldn't it be a better idea to use it for a cleaner future with green gas? By doing this, we can add value and contribute towards a sustainable society.’

In Groningen gist, Koen examines the residual flows from breweries and Dennis looks at those from the catering industry. The catering companies appear to offer the most potential. The study provides answers to questions such as: what are the residual flows from a restaurant? Can you process these? What are the problems? Where do you process the flows and how much volume does that produce? ‘GasTerra is actively involved in innovative projects in green gas production’, according to Geert. ‘Such as high-pressure fermentation technology at EnTranCe in Groningen. Residual flows from restaurants could possibly be processed using the innovative technology. Or in the existing municipal fermentation plant at Attero. We want to bring together a number of smaller projects to form one overall sustainable project.’

Everyone is enthusiastic

Is green gas insignificant? Certainly not. ‘During the summer months, green gas produced by waste processing company Attero already accounts for a large proportion of the gas in the Groningen gas network. Therefore, at local level, we're already talking about volumes that really matter. From this smaller scale, we'd like to explore ways of exploiting the system further.’ There is a lot of enthusiasm. This was shown in April at a beer festival in Groningen, where the students held an inspiring presentation. They compared Groningen ferments with a previous initiative using waste coffee grounds; this led to large-scale mushroom cultivation.’ Geert simply wants to say that there are enough inspiring ideas, also in areas where GasTerra is not normally so quick off the mark. ‘It's good for GasTerra to stick its neck out. I think that this is a really good opportunity for us.’

Follow-up study

Koen and Dennis have now completed their work and Koen has been nominated for a dissertation prize. For Geert, this is one more example of the innovative potential of the project. With a fresh look at bottom-up sustainability and cooperation between stakeholders from government, education and industry as the starting point. He definitely wants to carry this on. ‘Within GasTerra we have a green gas department where we are investigating how we can further develop green gas potential in the north. We're continuing to work with Groningen ferments to see how local catering establishments, in particular, can implement fermentation themselves in small collectives. It's possible that they will achieve economies of scale by doing so, which makes it worthwhile for them. Clearly there is enough material for a follow-up study.’