Sustainable Biowaste Management in Cities

On May 31, 2022, the municipality of Kalundborg (Denmark) has welcomed local representatives and policy makers form the city of Murcia (Spain) to visit and learn from the selective collection and valorization of urban biowaste carried out in the area. In the trip, participants have visited Kalundborg Symbiosis – the world´s leading industrial symbiosis – and the facilities of the company Unibio – a pioneering venture operating in the biotechnology sector with core competences within fermentation technologies.
Kalundborg Symbiosis gathers a group of 13 partner organisations, which play distinct roles within the Symbiosis – among them, the afore mentioned Unibio.
In total, ARGO, a Kalundborg Symbiosis member, receives wastes from recycling stations in nine municipalities. Recyclable waste, which is 80%, is sorted into fractions and subsequently disposed of to the recycling industry, and the remaining 20% is used for energy production.

Then, the company Gemidan works on the pre-treatment of organic wastes (like food waste) for the Municipality of Kalundborg with its Gemidan Ecogi technology. The Gemidan Ecogi pre-treatment system combines flexible de-packaging and pre-treatment systems: it accepts any type of food packaging. Once in the system, the Ecogi technology is able to de-package food wastes, separate plastics, digest organic wastes, and produce clean quality bio-pulp as a result: excellent for biogas production.

As a reference, the system can process up to 10 to 13 ton of organic waste per hour (250 ton/day), and it can handle up to 20% of contamination in the wastes (that is, waste bags with materials or wastes that should not be there, as plastics in the case of biowaste treatments). Currently, 4 Ecogi plants are operative in Denmark, and overall, the plants are low cost in maintenance and expected to last in the long term.

In this context, Unibio is prominent in the group for its innovative technologies for protein production, which convert methane from any source into a highly concentrated protein raw material used as ingredients in feed. Within the Valuewaste project, Unibio’s role focuses in this area, integrating the production of protein ingredients from methanotrophic bacteria that fed on biogas into the Valuewaste valorisation lines & technologies.
All in all, the representative organisations from Murcia (Spain) got a clear view of how the waste management schemes in Kalundborg worked, taking back home valuable lessons for the municipality and the Valuewaste project.

“We have learnt a lot in this mission, I hope we can maybe replicate some of them back in Murcia” – Enrique Luna Ruiz-Cabello, Director of technical services and projects, “Business association of labor and investee societies of the Murcia Region” AMUSAL.

The Valuewaste project started back in 2018, gathers 17 partners from 5 EU countries and, after almost 4 years, it is now reaching to its end in October 2022. The goal of the project is to foster the adoption of circular valorisation schemes for urban biowaste in cities across Europe. To keep up collaboration and experiences exchange, Valuewaste will foster a second exchange visit next September 2022, in this occasion in Murcia, Spain – hosted by the Murcia City Hall – where Kalundborg Municipality, Kalundborg Symbiosis and other stakeholders will be invited.