INCINERATION OF PLASTIC WASTE

The use of incineration to generate energy (waste to energy) from plastic waste is widely acknowledged as counterproductive to a circular economy concept and mitigating climate change, at the same time as it generates toxic pollutants. The EU has an overcapacity of incineration developed as landfilling of waste was banned or subject to high disposal fees meant to deter dumping of wastes that could otherwise be recycled, as well as to protect groundwater supplies.

However, in recent years it was recognized that incineration of municipal waste, a large part of which is plastic, was consuming resources in a way inconsistent with the circular economy, in competion with recycling, and in some cases, resulting in waste having to be imported to feed the incinerators. In 2016, it was estimated that 11.3 million tons of plastic were incinerated in the EU – a 61% increase in a decade (Delva et al., 2019). These concerns have led to EU proposals for taxes on waste incineration, and specifically plastic incineration. As of June 2018, The EU’s budget commissioner, Günther Oettinger, has announced plans to introduce a new EU-wide tax of 80 Euro cents per every kilogram of plastic waste burned (€800 per metric tonne). Denmark has already imposed a tax on mixed waste incineration of USD $45 per ton (1016 kg).

In further recognition of the Global Warming Potential of incinerator emissions, the EU has excluded waste to energy and waste incineration from the newly developed Sustainable Finance Taxonomy.63 The EU Commission has agreed that the taxonomy, a regulatory instrument to direct investment to climate change mitigation, should exclude incin eration from its list of activities, with Article 9 stating that minimizing incineration and avoiding disposal of waste will contribute to the circular economy.

Figure 41. 2006-2016 plastic waste treatment evolution in Europe.

Aside from high volumes of climate damaging emissions, incineration of plastic waste also produces toxic compounds as emissions and residues. Emissions of highly toxic chemicals, such as persistent organic pollutants, in particular dioxins, have blighted the industry for decades with evidence of harm to human health from emissions and impacts on the food chain .

At enormous expense, modern incinerators have reduced atmospheric dioxin emissions significantly by transferring them, via filtration and scrubbing devices, to the solid residues of incineration – bottom ash and fly ash. However, this had led to evidence of food chain contamination, as the ash re-enters the environment (IPEN, Arnika, NTN 2017). In addition, questions are now being raised as to the real level of dioxin emissions from incinerators, as the regular monitoring technology and requirements have come under scrutiny. Standard equipment takes one or two ‘snapshot’ samples a year where new sampling units can generate almost continuous data. The use of semi-continuous sampling equipment has revealed ‘hidden dioxin emissions’ that are not picked up under the standard methods used for decades, and commonly still in use .

Figure 42. Hidden dioxin emissions from a state-of-the-art incinerator, the Netherlands.

Long-term semi-continuous sampling by the AMESA system demonstrated that even a state-of-the-art incinerator in the Netherlands was emitting much higher levels of dioxin than were shown by the old standard monitoring method. Very high dioxin emissions were recorded during start-up conditions following internal cleaning maintenance of the incinerator (see Figure 42) using the AMESA system.

Additives in plastic can also lead to uncontrolled and unregulated emissions. As an example, the use of nanofillers in plastics can lead to chemicals of concern being emitted from the stacks of incinerators. Nanoparticle emissions from incinerators are entirely unregulated. According to the European Commission “thermoplastics with nanofillers will generate significant levels of high-weight polyaromatic hydrocarbons (PAHs), which are considered more toxic than low-weight PAHs. These substances are assumed to be formed on the released nanoparticulate matter during thermal decomposition” .

In addition to toxic emissions, releases, and high GWP, incineration competes with recycling technology for materials such as plastics. In the past, the incinerator industry claimed that they must be a ‘part of the mix’ for the circular economy, and that their target waste is residual, post-recycling waste unmanageable by any other way than landfilling. However, the emergence of chemical recycling that can manage contaminated residual plastic waste may provide a better resource recovery outcome than incineration, which somewhat undermines the claim that incineration is the only option for such waste.

Incineration remains one of the most polluting ‘false solutions’ to the plastic pollution problem, and in the long-term, does not appear to have any role to play in the environmentally sound management of plastic waste in a circular economy.