5 may 2015
Advancing to a circular economy
Denmark’s Billund BioRefinery is known as many things for the country: energy producer, jobs creator, technology showcase, export generator, resource conserver, sustainability promoter. Even in today’s over-marketed world, it’s an impressive string of superlatives for any company. But, in the case of the Billund BioRefinery currently being constructed in Denmark — also known as the Wastewater TreatmentPlant of the Future — the rave reviews arecoming not from its builder, Veolia Water Technologies subsidiary Krüger A/S, but rather through a string of international awards and statements by local and national government officials.
“Billund BioRefinery is an example of people continuously striving to do better, develop new products and come up with solutions that improve the environment in Denmark and the rest of the world,” said the Denmark’s Environment Minister Kirsten Brosbøl, speaking at a recent awards ceremony.
In 2014, Billund BioRefinery was awarded a distinction in the Global Water Awards for Water Reuse Project of the Year, a European Business Award for the Environment, and Denmark’s Svend Auken Award for dedicated efforts in the environmental arena, joining a distinguished list of former recipients that includes the World Wildlife Fund.
A joint project between Krüger, the municipality of Billund, and its utility company Billund Vand A/S, the pilot plant is designed to be a model for complementary wastewater and biomass treatment technologies that can work in synergy. It will also serve as a showcase for international marketing of Danish environmental innovation, demonstrating the results achievable in collecting the most efficient and advanced wastewater solutions in one facility. The facility’s parallel wastewater and biomass synergistic treatment lines link industrial and municipal waste treatment — effectively closing the local resource circle. The dualfeed plant will treat both organic waste and wastewater, with a total capacity of 70,000 population equivalent and 4,200 tons of waste per year from both households and industries in the Billund area.
In addition to optimizing water quality, the green technologies transform the wastewater treatment plant into a modern biorefinery that converts wastewater and waste into clean water and energy. The wastewater treatment process produces biomass, which is then treated to generate biogas for energy production that reduces the plant’s power requirements and creates additional income through the sale of surplus energy to the local grid.
The plant’s environmental technologies enable the efficient combination of wastewater treatment and bio gasification of organic waste to produce three times as much energy as required to operate the treatment plant. Other plant byproducts will include efficient, odor-free organic fertilizer, and eventually, phosphorus and biodegradable bioplastics.“The big difference with the Billund BioRefinery project is that we’re thinking more broadly than looking simply at wastewater treatment
,” says Mette Dam Jensen, a process engineer at Krüger and member of the project management team. “We’re taking a strategic perspective on resource recovery and considering the relationship with farming, industry, and the community. We’re demonstrating that it’s possible to close these local loops and move toward a circular economy — and that projects like this can be achieved on an even higher level of efficiency and an even larger scale
Wastewater plant of the future
Exelys™ reduces sludge through improved digestion and dewatering while boosting gas production
The biorefinery performance is dependent on an array of both new and established Veolia treatment technologies that are being progressively brought on line, including:
- Exelys™: Billund BioRefinery is Denmark’s first full-scale demonstration of the stateof- the art continuous thermal hydrolysis technology. Compact and robust, it reduces sludge cake through improved digestion and dewatering, while boosting gas production by 20 to 40 percent.
- STAR Utility Solutions®: An advanced online system that measures processes online, ensuring optimal cleaning while minimizing energy and chemicals use. In the event of heavy precipitation events, part of the plant’s treatment capacity can be switched over to treat storm water — optimizing pollution control and reducing the risk of overflow. By integrating multifunctional use of the mechanical filter in the plant’s management strategy and combining an online warning system, Billund is taking a first step toward coordination of the municipality’s treatment plants and drainage systems. Other controls include monitoring and optimization of the biomass feed in order to maximize biogas production and prevent overloading of the digesters.
- ANITA™Mox: An efficient moving bed biofilm reactor (MBBR) treatment technology, which increases the plant’s capacity and energy efficiency by converting ammonia to nitrogen without the use of organic material using annamox bacteria.
- BioPasteur™ technology: This product heats sludge prior to digestion to ensure that it is completely hygienic.
- Hydrotech™ Discfilter: Mechanical and self-cleaning, the filter is implemented in wastewater facilities throughout the world. At Billund, the Hydrotech filters can be dosed with precipitation chemicals for precise control of nutrients and suspended materials, significantly improving effluent quality.
Overall the new plant configuration will improve water quality to such a degree that only 25 percent of the discharge limit for nitrogen, phosphorus, and suspended materials will be used. This reduces the amount of nutrients released into the environment and will help to maintain the unique biodiversity in the surrounding mudflats of the adjacent river outlet.
On the job
Already attracting interest worldwide, the Billund BioRefinery is also a modern-day example of how a municipality is able to support its government’s desire toward reducing waste through resource recovery. With a total budget of nearly US$12 million, Billund BioRefinery is being constructed with financial support from the Ministry of the Environment and the Foundation for Development of Technology in the Danish Water Sector. The municipality of Billund has a record of successful environmental efforts that has attracted international attention, including sorting-at-the-source, bio gasification of household food waste, and the turning of wastewater sludge into an end product as highly-efficient and odorless organic fertilizer.
For Brosbøl, who dug the first mini-loader shovelful at the plant’s groundbreaking ceremony in August, Billund BioRefinery will serve as a “lighthouse project that will resonate internationally, benefiting the environment and export business and creating Danish jobs in the future.” Denmark’s green solutions already amounts to 10 percent of its exports, or $13.70 billion annually. In addition to construction jobs, the project has led to additional hiring at Billund Vand, with the potential for additional employment fueled by exports.
Resource recovery, future focus
In combining the strongest environmental technologies for water treatment and biogas in a single full-scale demonstration project, the Billund BioRefinery exemplifies a philosophy that waste and wastewater are not problems but rather resources that offer immense potential for the environment. In improving wastewater treatment, utilization of the energy and nutrients in wastewater and organic waste, and generating biogas and usable by-products, the facility is an example of a more sustainable cycle of resource use.
“The Wastewater Treatment Plant of the Future is also a model example of what we can achieve through public-private cooperation,” Brosbøl said. “It is examples like this that we need for the future in Denmark – and all over the world, for that matter.”