News
9 october 2017

Billund Biorefinery

Resource Recovery for the Future

The Danish wastewater treatment plant of tomorrow, Billund BioRefinery builds upon the latest developments in the field and a combination of unique global technologies.
The concept combines new technologies to process raw materials consisting of wastewater, organic household waste and organic waste from industries and agriculture. Outputs are purified water and green energy (in the form of heat and electricity) while the amount of sludge is reduced and refined to an odorless, easily manageable and very efficient organic fertilizer for agricultural purposes.
 
Billund Biorefinery
 
Great success achieved through public-private partnership
The project is developed through a strong partnership between the Danish Utility company Billund Vand A/S and Krüger A/S, a Veolia Water Technologies subsidiary.
The vision behind the project is that waste and wastewater are not waste – they are resources, and these resources contain immense potential to implement a circular economy at wastewater treatment plants.
 
The ambition has been achieved owing to a well-functioning public-private partnership where joint targets and clearly defined rules have contributed to a successful project.
 

From the beginning, we wished to create a joint identity in the project. We put a lot of emphasis on letting the key employees from Krüger A/S and Billund Vand get to know each other. The purpose was not only to create a technological lighthouse project but to develop the project with as much benefit as possible for all parties involved”, says Billund Vand Managing Director Ole P. Johnsen.

 
The Billund BioRefinfery was officially inaugurated in June this year, but has shown its worth as a Lighthouse Project over its 4-year development period. The environmental results have exceeded expectations and the international interest has been very high.
 

Billund BioRefinery has in a very short time proven its value on the export markets. It is a wastewater treatment plant that is able to achieve better treatment results, lower the energy consumption and make better use of the resources in the wastewater than other plants”, says Danish Minister for Environment and Food Esben Lunde Larsen who visited the plant last spring to get a personal first-hand impression of the plant.

 
Continuous thermal hydrolysis of sludge is the cornerstone of the energy plant
Veolia’s patented Exelys® technology with double lysis digestion (DLD), is a central element of Billund BioRefinery and is the key to transforming the treatment plant into a true
energy powerhouse. As part of the expansion of the treatment plant, it is now possible to process much larger amounts of both household and industrial waste at the plant.
 
98% of all of Billund’s wastewater and household waste sorted at source is now recycled, which is totally unique at international level and creates a whole new outlook on wastewater and waste as valuable resources.
 
Thermal hydrolysis is the most effective technology for increasing biogas production from different types of waste. Exelys ensures maximum energy recovery with the lowest possible energy consumption. The process allows more complex substrates to be reduced downstream in the digester. The Exelys plant only treats a partial stream of the total biomass, namely that part that includes wastewater sludge and solid waste, including  household waste sorted at source.
After the Exelys technology was put into operation, all expectations in terms of energy production, treatment efficiency and reduction of residues for disposal have been more than fulfilled. The energy surplus is distributed to the power and district heating network and benefits the local community. Sludge for disposal is also significantly reduced and the total amount of nutrients discharged in the water to recipients is approximately 60% of that established in the legislation.
 
Billund Exelys
 
Expansion of digester capacity
The establishment of the Exelys plant for thermal hydrolysis of digested sludge creates the opportunity to exploit the larger digester volume because, in principle, the sludge can be digested twice. Household waste and sludge from the treatment plant is thus led to anaerobic digestion under thermophilic conditions (52-55°C) in the new digester.
 
New thermophilic digester ensures maximum gas production
A new digester of 1,400 m3 has been set up, thereby creating the opportunity for better management of the digestion process and hence gas production. With the new digester in operation, sludge is sent together with household waste from the treatment plant to the new digester, while sludge from the Exelys plant is sent together with industrial waste to the existing digester.
 
The new digester has been designed with an innovative gas system (similar to the new Veolia patented GasTop) that is especially well-suited to the processing of biogas from thermophilic digesters. The gas washer alleviates condensation problems and foam in the gas pipelines. The gas washer has a builtin safety valve that is designed as a double siphon trap.
 

The Billund Biorefinery

 

98% of all of Billund's wastewater and household waste sorted at source is now recycled.


 
Billund Bioplastic