The role of waste incineration in a circular economy

Today, thermal waste treatment is a key component of waste management. It serves as a sink for pollutants by removing environmentally hazardous substances from the cycle. Its importance as a building block of the future German energy industry, however, is controversial.

waste incineration plant
© © iStock / Michael Utech

Latest figures published in February 2018 by the Federal Statistical Office, in 2017, thermal waste treatment plants in Germany incinerated 25.1 million tons of waste—including recyclable materials. From the point of view of the German Nature and Biodiversity Union (NABU), this would not be necessary in many cases. Michael Jedelhauser, Consultant for Circular Economy at NABU, says: Although waste incineration has its rationale in a circular economy, it should only be used where high-quality recycling of waste is not possible. A lot of material that could be recycled still goes into incineration, for example biowaste, plastic packaging and commercial waste. Hence, NABU proposes to set up organic bins throughout the country, to introduce a “design for recycling” for plastic packaging and to have commercial waste collected separately in municipalities on a legal basis.

No contradiction to a circular economy

Scientists of the Fraunhofer Institute for Environment, Safety and Energy Technology (Umsicht) emphasize that waste incineration does not contradict recycling management but should be seen as an addition. In their study from 2017 titled “The role of thermal waste treatment in circular economy”, Dr.-Ing. Markus Hiebel explains: “Looking at the current state of product development and human consumption, in the long term, thermal waste treatment will continue to be an essential supplement on the way to a circular economy. It helps to reduce conflicting goals where circular production and ways of thinking reach economic, legal and material limits today.”

In this context, the Fraunhofer study highlights the following advantages of thermal waste treatment: waste is inerted, sanitized and concentrated—and thus is removed from the cycle, energy and secondary raw materials can be obtained from waste that cannot be recycled. The Fraunhofer scientists hence conclude that waste incineration will thus remain an important component of waste treatment in the foreseeable future.

Waste-to-energy plants could close the gap

The role of waste incineration as a future component of energy generation, however, is controversially discussed in Germany. In its 2018 study “Energy generation from waste—status and potential in Germany up to 2030”, the Federal Environment Agency argues that waste-to-energy power plants could close the gap created by the closure of coal-fired power plants. Different from NABU that rather advises reducing waste incineration capacities in the medium and long term, putting forward the following arguments:

  • waste is not a renewable energy source,
  • more and more fossil-based waste such as plastic would also be incinerated,
  • it is to be feared that—even with declining waste volumes—plant operators have to make greater use of recyclable materials in order to utilize their kilns to capacity and operate them economically; this counteracts the efforts to increase material recycling.

More plastic incinerated due to import ban?

Thermal waste treatment also faces new challenges due to the Chinese import ban on plastic waste at the beginning of 2018. The Interest Group for Thermal Waste Treatment Plants in Germany (ITAD) considers an increase in plastic waste in Germany caused by the import ban possible:

Carsten Spohn, Managing Director of ITAD: “Our members are finding that commercial waste volumes are rising, as is the average calorific value. Both may be due to a higher proportion of plastic. We therefore assume that partial quantities that were previously exported to Southeast Asia now end up in German plants. Some commercial enterprises are increasingly disposing of plastic waste via the residual waste.”

As this fraction’s calorific value is almost three time higher compared to household waste, no large quantities can be accepted and recycled unmixed, resulting in more complex processes. And the increased calorific value also reduces the throughput capacity of a combustion boiler. Spohn: “The energetic utilization of non-recyclable plastic brings technological challenges for many thermal waste treatment plants, but all in all these challenges can be solved.”