A surplus from circular production

There is an urgent need for the future to be sustainable – using less resources, reuse and recycle. In this respect, the industry plays a crucial role in resource consumption, product design, and new business models. Process industry needs to take a smart approach, where embracing the green challenge can be turned into a competitive advantage.

Kalundborg Symbiosis was established in the early 1970s to take a circular approach where the main principal was the physical exchange of materials, energy, and water between two or more companies, turning what is normally seen as waste, into a resource.

Today, the symbiosis consists of 16 partners from water, energy, and health industries with an international outlook – all sharing the ambition to be carbon neutral within the next decades, be best global case on circular production, and strengthen 50 years of shared mindset.


Symbiosis on a lot of different resources

In Kalundborg Symbiosis, the city’s largest industrial companies collaborate across sectors and share their surpluses of energy, water, and materials with each other, so that one company’s surplus product can provide value to another. Today, more than 30 different streams of resources are shared between companies.

Public and private companies are physically connected to each other in the Symbiosis, and together they create profits – both the kind we measure on the bottom line, but also what comes from better utilization of resources. Kalundborg Symbiosis is based on innovative solutions that ensure resources are used more sustainably. However, the optimal production of the future is not always in sight, and solutions often need to be tested on a smaller scale before a new symbiosis flow can be established.


Strong cooperation on test and demonstration

Kalundborg Symbiosis is known throughout the world and helps to market Denmark as a green pioneer country. In addition, Symbiosis, as a local partnership with a focus on efficient resource utilization can contribute to achieving the government’s ambitious reduction target of 70% less CO2 emissions by 2030.

Annually, the symbiosis saves the partners and the environment for 4 million m3 of groundwater by using surface water and 586,000 tonnes of CO2. An on top of that, every year 62,000 tonnes of residual materials is being recycled. And since 2015, the CO2 emissions in the Symbiosis has been reduced by 80%. The local energy supply is CO2 neutral.

Over the years, Symbiosis has hosted test and demonstration facilities testing technologies for wastewater treatment by the use of microalgae, production of second-generation bioethanol, low-temperature pyrolysis, and much more.

“Growing demands on sustainable water supply to industry call for coordinated action and mutual focus on the area. The Symbiosis partnership provides the platform to timely overcome challenges and bottlenecks, to secure a managerial focus on water as an essential resource to the nature and industry”

Per Møller, Senior Symbiosis Developer, Kalundborg Symbiosis

Sometimes, even full-scale production can be established from the existing test and demonstration plants, for example RE Energy/Meliora Bio, as well as plants used for purposes other than those for which they were originally built.

Kalundborg Utility, for example, is now using the greenhouse originally built for microalgae plants for Denmark’s largest sludge mineralisation test plant for sustainable sludge treatment in collaboration with FORS and WSP.

Another good example of innovation can be found at Unibio, an innovative developer of protein production technology that converts methane from any source into a highly concentrated protein feedstock for use as an ingredient in animal feed. The technology developed by Unibio replicates the microbiological processes that occur in nature every day using the U-Loop® fermentor patented by Unibio. The fermentation technology has been demonstrated on a pilot and demonstration scale in Kalundborg using biogas supplied by Kalundborg Bioenergy.



Argo, Avista Green, Boehringer Ingelheim, Chr. Hansen, COMET, Intertek, Gyproc, Kalundborg Bioenergy, Kalundborg Utility, Kalundborg Municipality, Kalundborg Refinery, Meliora Bio, Novo Nordisk, Novozymes, Unibio, and Ørsted.


Per Møller
Senior Symbiosis Developer, Kalundborg Symbiosis

Nadejda Ulstrup-Hansen
Communications and Project Manager, Kalundborg Symbiosis