For the last few years, circularity, recycling and the reuse of materials and goods has been an overarching theme that is helping to preserve the Earth’s natural resources and improve the condition of the environment. At the core of this theme is waste; specifically, the questions of how to produce less waste, limit the utilisation of primary resources and increase reusability.
Application of the circular economy concept is necessary. Hopefully, it will ultimately lead to a situation where the waste produced by society is at an absolute minimum. At the moment and with current technology development, however, we in Europe are not able to sufficiently recycle all of our waste; in fact, we are not even close to doing so. What really happens to our waste? Very simplistically, some of it is recovered or reused and the rest ends up in landfills or in incineration plants. Many consider the latter as harmful, which is why it is good to be transparent and explain how waste fractions can be treated and why energy content should be recovered from certain waste fractions.
Energy recovery is part of the circular economy
Energy recovery from the waste fractions that are not suitable for recycling (i.e. the material’s properties have been degraded or depleted or the materials contain contaminants) must be separated from recyclable waste. In those cases, incineration eliminates environmental risks. In our view, the focus of the circular economy should go beyond just the materials; it should take a holistic approach and recognise also the energy role in the whole concept. The energy recovered from the thermal treatment of waste is just as useful as the energy recovered from the so-called waste heat generated by, e.g., data centres, industrial sites or even larger buildings. It is often technically feasible to capture this energy content and reuse it for other supply purposes.
Recyclability of materials and products must be the number one option – but we are not there yet
As for the waste markets, it is important to focus on the waste that has already been generated or will be generated in the coming years, waste that is often untreated due to the absence of sufficient methods or even funds in certain countries. What is needed are tools and measures to minimise the waste amounts as well as the implementation of rules on the smart design and recyclability of materials and products. With this in mind, we still have a huge problem at hand: the daily landfilling of tonnes of waste until the solutions mentioned above take effect. Rather than those waste fractions degrading in landfills, we could safely recover the energy content in waste-to-energy plants and use it to replace fossil fuels, which are still the source of heat for too many European households. According to CEWEP*, the electricity, heat and steam energy recovered from waste could produce 190 TWh of energy by 2035. This amount would be sufficient enough for more than 50 million people.
Of course, recyclable waste should not be diverted from recycling operations, and be sent to energy recovery prior to any sorting or separation. Materials should be recycled until they are no longer physically suitable. And only then should the remaining residues be delivered to an energy recovery facility, where the final treatment takes place and the electricity and heat are returned to the circular economy cycle.
Decontamination of waste by high-temperature incineration
Typically, we perceive waste as the stuff we see in our own trash bins, but that’s just the tip of the iceberg. Those waste fractions account for no more than 10% of the total waste stream (according to the EU Parliament: municipal waste accounts for less than a tenth of the more than 2.5 billion tonnes of waste generated in the EU every year). The rest consists of industrial waste fractions (like mining, manufacturing, construction, etc.), which probably have the biggest potential for scalable recycling. Some of the waste fractions in commercial, industrial and household waste streams are contaminated, like pharmaceutical and hospital waste, chemicals, etc. At the moment, the most sustainable way to treat those fractions is through controlled high-temperature incineration. The future might hold scalable alternatives for some of the waste fractions, but storing the contaminated waste is not an option. For right now and in the years ahead one of the most feasible alternatives will be high-temperature incineration.
Landfilling combustible waste should not be an option
A well-functioning circular economy should include energy recovery from waste as part of an integrated waste management system, at least for the foreseeable future. It should also recognise thermal energy recovery from buildings and processes as an integral part of the concept. These elements will help to mitigate greenhouse gas emissions by using less primary fuels (including fossil or bioenergy sources).
Landfilling combustible waste should not be an option, and the current regulations should be enhanced to cover all waste fractions (municipal, industrial and commercial) that can be recovered, with a focus on increased recyclability as well as the potential for material recovery.
*CEWEP - Confederation of European Waste-to-Energy Plants is the umbrella association of the operators of Waste-to-Energy plants across Europe.