Current state of waste to energy in Denmark
The present contribution provides a brief overview of the Danish WtE system, including waste incineration, biogasification, and other technologies, as well as the waste streams used as input.
The Danish waste management system in Denmark has a long tradition for recovering energy from waste, which goes back to the beginning of 1900. It was however not until the 1990’s the major shift from landfilling of waste to incineration of waste took off. That was the result of a landfill ban on biodegradable municipal solid waste, which was introduced in 1997. In 1985, 39% of all waste and 33% of household waste was deposited. Today, insignificant amounts of waste are going to landfills and Denmark is characterized by a high degree of incineration, amounting to 54% in 2010 (municipal solid waste, i.e. both household waste and industrial waste), which is the highest percentage and the highest amount of waste per capita in the EU2.
Even though Denmark has a tradition for recycling, the waste management infrastructure is centered on energy recovery through incineration. Denmark has a fully developed incineration infrastructure, with 30 Incineration plants localized across the country. In overall, there are three types of Incineration plants in Denmark (see Fig. 1):
Dedicated ("dedikerede", ed.) waste incineration plants, which primarily incinerate household waste and industry waste (24 plants);
Multi fired ("multifyrede", ed.) incineration plants, which incinerate household waste and industry waste together with biomass and/or natural gas (3 plants);
Other plants ("øvrige", ed.) which co-incinerate waste or incinerate hazardous waste (3 plants).
The majority of the incineration plants are inter-municipality owned. This means that they are owned by several municipalities together in order to establish and operate incineration plants which incinerate the waste generated in the owner municipalities and supply the inhabitants in the municipalities with district heating and electricity. This organization of a close co-operation between municipalities, waste management companies (operators) and district heating companies is the predominant way of organizing incineration plants in Denmark. An insignificant part is owned by single municipalities, district heating companies or private companies.
The total incineration capacity in Denmark is 3.6 million tons of waste from households and industries in 2011. All of the incinerators generate heat and almost all also generate power. All together, they provide about 5% of the total energy supply in Denmark, including 20% of the heat delivered to the central heating systems and 4.5% of the total electricity supply. Plants with the largest capacity are located in the large cities where the district heating systems are well developed. Therefore, the capacity of each incineration plant is larger for the plants localized in the cities compared to plants localized in smaller cities. So "Vestforbrændingen" and "Amager Resource Center" – two incineration plants located in the Copenhagen area – have the largest capacity. Denmark currently has an overcapacity on the incineration plants, meaning that some waste is imported from other countries (e.g. Norway and Great Britain) in order to fill up the plants. The overcapacity is seen as a result of the economic crisis, but the overcapacity is expected to increase in the coming years as a result of the new waste management strategy.
As with energy recovery through incineration, Denmark also has a long tradition for energy recovery through biogas production and Denmark therefore has a rather well-developed infrastructure for biogas. In overall, Denmark has 154 biogas plants, distributed in 4 different types of biogas plants:
57 Sewage sludge treatment plants
5 industrial biogas plants
25 landfill gas plants
67 agricultural plants (21 centralized and 46 decentralized)
The establishment of biogas plants in Denmark started in the 1920’ees with a special focus on sewage sludge treatment. In the late 1980’ees the development however stagnated because of no technological progress and therefore there were very low production rates and most importantly, the oil crisis was over. In Denmark it was however decided to move forward with the development of biogas production in the agricultural sector. The energy prices were still high because of taxes on fossil fuels and more important the biogas development became an important part of the NPO Action Plan (Nitrate, phosphorus and organic substances), which aimed to minimize the pollution of water environments.
For the agricultural sector the NPO action plan demanded the establishment of slurry tanks. As a result of this, the ministries for energy, environment and agriculture launched a report named centralized biogas plants and the NPO action plan. The main conclusion of the report was that centralized biogas plants would be a cost-effective way for the farmers to fulfill the targets of the NPO action plan, as the manure could be used as feedstock in the biogas plants. As a result, an action plan for centralized biogas plants was initiated. This was the beginning of the establishment of a large range of centralized biogas plants in Denmark and at that point, biogas plants became an acknowledged part of the energy supply system. At the same time, technology providers within biogas started to emerge in the Danish waste-to-energy cluster. As such, the biogas infrastructure is closely connected to the Danish biogas history which signifies a position of strength within biogas plants treating sewage sludge and agricultural plants. In the new national waste management strategy, published in 2013, it is specified that the organic fraction from household waste and from the service sector increasingly should be used as feedstock in the agricultural biogas plants in order to enhance the energy output. Therefore, there is expected to be an increase in the number of agricultural plants where the organic waste will be used as feedstock in combination with the liquid manure. Furthermore, there will also be an increase in the energy supply from the biogas production. As such, the current waste management plan is diverting waste away from incineration towards biogas production.
The review of the Danish waste management system illustrates that Denmark has a long tradition for converting waste to energy. This tradition should be seen in close connection with the Danish environmental policy but also the energy policy, where taxes on fossil fuels have pushed for alternative ways to produce energy. The Danish tradition for focusing on alternative energy sources has had a major importance for the development of the incineration field. As a result Danish companies specialized in incineration technologies have evolved and are now some of the biggest players in the market for incineration technologies and turnkey solutions in the world. In addition to this, the emerging market for biogas in Denmark has given rise to many Danish companies within biogas technologies. Whereas the market for incineration technologies is a mature market consisting of few very large well-established companies, the market for biogas technologies is still developing and is characterized by a large amount of smaller companies. As such, the development of the waste management system and infrastructure in Denmark goes hand in hand with the development of the waste-to-energy cluster.
2 Drivers for waste-to-energy in Europe, 2013, FORA, COOLSWEEP
Created by Jonas Mortensen (clean - innovating green solutions)
, (2014-11-24), last modified by Jonas Mortensen (clean - innovating green solutions)
Waste-to-Energy (WtE) facility
Renergia, a brand new Waste-to-Energy (WtE) facility opened in Canton Lucerne, shows that Waste-to-Energy can provide reliable heat for industries.
Category: Incineration / Waste-to-Energy plant
Executing firm: Renergia Zentralschweiz AG
MBT Ljubljana, Slovenia
In Slovenia arises one of the largest and most modern waste treatment plants in Europe.
Category: Recycling / MBT
Executing firm: STRABAG AG
Flue Gas Cleaning
The final unit of the incineration plant is one of the most important parts as it has the objective of cleaning the air pollutants produced.
Executing firm: ete.a - Ingenieurgesellschaft für Energie– und Umweltengineering & Beratung mbH
Batch Dry Fermentation
The biogas produced from the waste can be converted in a CHP to electrical and thermal energy or fed as processed bio-methane into the natural gas grid or used as fuel (CNG).
Category: Recycling / Fermentation
Executing firm: BEKON Energy Technologies Co. & KG
MBT Warsaw, Poland
The Bio-Dry™ system is a static, aerated and flexibly enclosed reactor for the biological drying of various solid waste matters containing some biodegradable contents.
Category: Recycling / MBT
Executing firm: Convaero GmbH