Novozymes and Novo Nordisk, two Danish biotech firms with neighboring facilities, have come together to set up a biogas reactor to use wastewater from their facilities to produce biogas, which can generate 47,000 MWh of electricity a year, equal to the power from 7 offshore wind turbines, the companies say.
Novozymes said it uses a lot of energy and using the biogas reactor enables it to reduce carbon emissions by 21,000 tons annually. It also brings down production costs and makes the firm more competitive.
The company told Energy Manager Today that the biogas reactor was started up towards the end of May and early June – it takes a while for the microorganisms to begin working in wastewater, so the start-up process was spread out. Both firms use the resulting electricity, as well as the steam and heat generated by the process, and they also sell excess to the grid.
Both companies have facilities in the Kalundborg industrial area in Denmark and both have invested in the biogas reactor, but Novozymes owns and operates it and the water purification plant that is part of the reactor system.
Both firms are part of Kalundborg’s industrial symbiosis, wherein public and private enterprises buy and sell waste products from their industrial production in a closed cycle. The residual products that are traded include steam, dust, gases, heat, slurry and any other waste product that can be physically transported from one enterprise to another.
With the symbiosis circle, a residual product originating at one enterprise becomes the raw material of another enterprise.
It’s not just manufacturing companies, but also retailers that have woken up to the potential in their waste streams that can be converted into biogas. In October last year, Marks & Spencer signed a deal with waste management company Shanks Group to convert the retailer’s food waste to biogas that will produce enough renewable energy to power 33 M&S Simply Food stores.