Mission Zero Waste

Sweden’s recycling practices and waste-to-energy industry are unmatched.
By Keith Loria | March 04, 2019

Fueled by population growth and a growing global economy, waste volumes around the world continue to escalate. In response, many countries have beefed up their efforts to increase recycling rates and implement more waste-to-energy (WTE) initiatives.

One of the most advanced countries when it comes to WTE measures is Sweden. While the average European country sends nearly 25 percent of household waste to the landfill, and the U.S. regularly sends about 40 percent, Sweden’s latest figures show it sent just half a percent of its waste to landfills in 2017. The country recycles more than 99 percent of all household waste, compared to only 38 percent 40 years ago.

Preventing waste creation became an important initiative of the Swedish government around 1976, when leaders realized the benefit of energy recovery is many times greater than sending waste to the landfill. Today, Swedish WTE efforts provide district heating and electricity corresponding to the heating of more than one million households, and electricity production to a little more than 600,000 households.

In 64 percent of Sweden’s municipalities, the collection of food and residual waste is primarily carried out by private contractors, with 33 percent of municipalities carrying out collection themselves, and the others using a combination of private contractors and in-house collection services. Waste treatment is either undertaken by the municipalities themselves, or by an external contractor, which can be a different municipality, enterprise or private company. The distribution between the various structures depends on the method of waste treatment.

Anna-Carin Gripwall, director of communication for Avfall Sverige, the Swedish Waste Management Association, says one reason for Sweden being at the forefront when it comes to waste management is that many years ago, the government began crafting clear laws and regulations on waste management. “They developed strong rules for sorting, collection and treatment, and also in getting provisions for the products through a well-developed district heating system,” she says. “The rules and regulations have contributed to develop Swedish waste management both technically, organizationally and legally.”

Making a Difference
Last year, the quantity of household waste treated was over 4.7 million tons—an increase of 2.5 percent over 2016, with the amount of household waste going to landfill decreasing by 24 percent to 23,650 tons. Weine Wiqvist, Avfall Sverige’s CEO, would like to see Sweden residents do even more with recycling, noting that reusing materials or products turns into using less energy to create a product, rather than burning one and making another from scratch. Therefore, he is championing to move “up the refuse ladder” in the country.

Leadership at Avfall Sverige understand that many countries see Sweden as a good example for WTE, justifying its continuation of developing sound WTE practices at a rapid pace.

“There are high environmental goals and requirements set by the government  that we must live up to, so it is important to continue to maintain a high level of work—be it sorting, collection, etc.—and this helps continue to motivate the population,” Gripwall says. “In addition to this, the Swedes are a people who like nature and outdoors, and may be more interested in preserving a clean environment than others.”

Avfall Sverige has partnered with other stakeholders in the industry to develop waste indicators as guidance for measuring and monitoring the development toward resource-efficient waste management. These indicators are also a tool for monitoring development and work with Avfall Sverige’s future vision of “Zero Waste.”

Jon Engstrom, head of unit at the Swedish Environmental Protection Agency based in Stockholm, Sweden, was impressed that in 2018, as it was the year prior, less than 1 percent of the country’s household waste was landfilled. “I believe that the fact that EPRs have been in place for a relatively long time in Sweden is one success factor when it comes to separate collection,” he said. “Simply, there is now high awareness among the public concerning the importance of separate collection of waste.”

Still, Engstrom believes there remains a great challenge to actually reuse the material in an efficient way and create a situation that will take Sweden further up in the waste hierarchy.

“The fact that a lot of waste goes to WTE facilities also makes it very important that those facilities actually use the best available techniques for emission purification and treatment of ashes to minimize any negative environmental impact,” he says. “That is a great responsibility for all stakeholders involved in the waste chain, including authorities involved in monitoring, permitting processes and implementation of relevant regulation.”

A US Comparison
Ted Michaels, president of the Energy Recovery Council, based in Arlington, Virginia, notes the U.S. is not equipped the way Sweden is to utilize WTE in such a positive way, but that the country is still strong in its efforts. “Waste-to-energy facilities operate in very challenging market conditions in the U.S., given low landfill prices and low wholesale electricity prices,” he says. “In order for the U.S. to rely on WTE to the extent Sweden has, there will have to be adoption of policies, like in Sweden, that makes investment in new WTE more in line with the cost of landfilling.”

Currently, U.S. waste-to-energy facilities produce approximately 14 million megawatt-hours (MWh) of electricity each year. In addition, a number of facilities export steam to local users for heating, cooling or industrial processes. “Despite the closure of some WTE facilities in the past 10 years, the amount of renewable energy produced by WTE in the U.S. has remained very steady, which is attributable to increased efficiency, improved availability, and an excellent operational track record,” Michaels says.

Importing Waste
While Gripwall doesn’t believe Sweden is dependent on WTE, Avfall Sverige is pleased that so many efficient plants in the country make use of waste by turning it into energy, and that there’s such a well-developed district heating system. “Waste incineration is a compliment to material recycling, and a very important prerequisite for landfill restrictions such as a landfill ban on organic and combustible waste and a landfill tax,” she says. “People do not mind energy recovery; they understand that the waste that occurs must be treated in some way. What occasionally stirs up emotions is the fact that we import waste.”

Sweden has such an incredible recycling rate that in order to keep its WTE plants going, it imports trash from other countries, as it does not have enough of its own. “We are selling an environmental service to countries that do not have the capacity to take care of their waste in an environmentally correct manner,” Gripwall says. “The Swedish plants are paid to receive and treat the waste. And the environmental benefit is double, thanks to the negative environmental impact of putting the waste on landfill in the country of origin decreases, and we use the waste to generate heat and electricity that Sweden needs, replacing fossil fuels.”

Plants in Action
The EU Framework Directive on Waste and the Swedish Waste Ordinance classifies waste incineration with efficient energy recovery as recycling, and the Swedish plants fulfill the energy efficiency criterion by good margin.

Sweden’s Sävenäs in Gothenburg is one of the most advanced plants of its kind in the world for incineration of waste for the production of heating and electricity. Marie-Louice Flach, press officer for Renova, a government-owned energy company that operates Sävenäs in Gothenburg, says approximately 300 trucks deliver waste to the plant on a daily basis, which is then burned in three furnaces with the thermal energy generated transformed into electricity and district heating. “From every ton of waste combusted, we will recover 3.3 MWh of energy in the form of electricity and district heating, with 60 percent of our electricity production labeled as biofuel-based origin,” she says. “Each year, the waste-to-energy plant provides 30 percent of district heating in the region's network, and five percent of the electricity needs for Gothenburg’s total population.”

The smoke that derives from incineration plants consists of 99.9 percent nontoxic carbon dioxide and water, though it is still filtered through dry filters and water. The sludge from the dirty filter water is used to refill abandoned mines. Furthermore, Renova’s treatment facility for sorted food waste is situated at Marieholm in Gothenburg, where, once pulverized, compressed, strained and mixed with liquid food waste, the final product is transformed into a slurry suitable for biogas production.

Renova’s other landfill site at Tagene is primarily intended for ash from waste combustion. Flach explains that the facility extracts scrap metal and bottom ash from the cinders from its WTE plant so that these materials can be recycled. “We are proud of our environmental concerns,” Flach says. “We are well below legislated emission values. About one-fifth of the waste is also material recycled in the waste-to-energy  process.”

According to data from Avfall Sverige, last year, 2.4 million tons of household waste went to energy recovery, a rise of six percent from the previous year. Converting waste to energy met the heating needs of 1.25 million apartments, and the electricity needs of 680,000 apartments. In 2017, more than 18.3 terawatt-hours (TWh) of energy was produced, of which 16.1 was used for heating and the remainder for electricity. Additionally, three plants reported that they delivered 74,610 MWh of district cooling. “Energy recovery makes up half of the total amount of treated household waste, and the increase in household waste from 2016 to 2017 is partly attributable to bulky waste from recycling centers,” Gripwall says. “Sweden recovers more energy from waste than any other country in Europe, with nearly 3 MWh per ton.”

In addition to household waste, 3.7 million tons of other waste—primarily industrial waste—was treated by Swedish plants. Swedish energy recovery plants also treated more than 1.4 million tons of waste from other European countries, 535,000 tons of which were household waste. “This waste contributes to the fuel supply in Sweden, and solves some waste management problems in exporting countries,” Gripwall says. “Energy recovery also occurs in plants that do not treat household waste, however, there are no comprehensive statistics on the total energy recovery.”

Landfill Gas
Landfill gas capture and use is another integral component of Sweden’s waste-to-energy efforts. Produced at landfills where organic waste was deposited in the past, it’s nearly 50 percent methane, with the other half comprised of carbon dioxide, nitrogen and small amounts of other gases. “It contains methane, so it must be collected to reduce its environmental impact,” Gripwall says. “Since the ban on organic waste going to landfill was introduced, the formation of gas at landfill sites has progressively decreased.”

In 2017, about 142 GWh of landfill gas was collected at 40 waste treatment plants, of which 102 GWh was used for energy. Energy recovery consisted of 18.4 GWh in the form of electricity, the rest in heating.

Into the future, Sweden is poised to remain the global leader in waste recycling and energy recovery. With 2020 just around the corner, the country is on track to achieve its ultimate goal of zero waste.

Author: Keith Loria
Freelance Journalist
[email protected]