Recycling, Incineration or Landfill?

There are three key options for handling plastic waste: recycling, incineration or disposal in landfill. What should we choose?

What seems like a simple question can sometimes be complex. Opinions differ depending on what particular environmental, health or economic issues someone cares about. Impact of different methods can be assessed across multiple factors including greenhouse gas emissions, energy use, local pollution, and cost of processing.

Reference	Material/application	Global warming potential (GWP) best-mid-worst	Total energy use (TEU) best-mid-worst
Arena et al. 2003	PE and PET liquid containers	R-L-I	R-I-L
Beigl and Salhofer 2004	Plastic packaging	R-I	-
Chilton et al. 2010	PET	R-I	-
Craighill and Powell 1996	PET, HDPE and PVC	R-L	-
Dodbiba et al. 2008	Plastics (PE, PS and PVC)	R-I	-
Eriksson and Finnveden 2009	Non-recyclable plastic	I-L	-
Eriksson et al. 2005	PE PE, PP, PS, and PET	R-I-L R-I-L	R-I-L R-I-L
Finnveden et al. 2005	PVC PE, PP, PS, PET and PVC	R=I-L I-L-R	R-I-L I-R-L
Foolmaun and Ramjeeawon 2013	PET	R-L-I	R-I-L
Grant et al. 2001	PET, HDPE AND PVC	R-L	R-L
Moberg et al. 2005	PET	R-I-L	R-I-L
Mølgaard 1995	Plastics Plastics	- -	R-I-L I-L-R
Perigini et al. 2004	PE and PET liquid containers	R-L-I	R-I-L
Perigini et al. 2005	PE and PET liquid containers	R-L-I	R-I-L
Rajendran et al. 2013	Plastics	R-I	-
US EPA 2006	HDPE, LDPE and PET	R-L-I	R-I-L
Wenisch et al. 2004	Plastics	R=L	-
Wollny et al. 2001	Plastic packaging	R-L-I	R-I-L
M. Al-Maaded et al. 2012	Plastics, non-specified Plastics	R-L R-L-I	- R-I-L
Shonfield 2008	Plastics	I-L-R	-

The conclusions of a range of location-specific studies assessing the relative global warming potential (GWP) and total energy use (TEU) of the three methods. Each is shown from lowest impact to highest impact (e.g. R<L<I means recycling has the lowest impact, followed by landfill, then incineration has the highest).

Recycling had the lowest global warming potential and energy use across nearly all of the studies. From an environmental perspective, recycling is usually the best option. This typically holds true, but note that there are a few caveats:

• this is based on the assumption that recycled material is a one-for-one displacement of primary plastic production, i.e. each tonne of recycled material prevents one tonne of primary material being produced. However, this is not always the case. Recycling processes can often lead to products of lower quality and economic value — often termed ‘downcycling’. This means that we cannot take for granted that this substitution for primary production is one-to-one.
• much of the plastic we recycle can only be recycled once or twice (as we answer, here). Then it will end up in landfill or incinerated. This means that whilst recycling is the best of the three management options, it’s not a silver bullet. Recycling only delays — rather than prevents — disposal in landfill or incineration.
• whilst recycling has clear environmental benefits, it’s not always the most economically-favourable choice. The relative profitability between recycling and the production of new plastic is strongly determined by oil prices. When oil prices are low, it can be cheaper to make raw plastics than to recycle. For example, when crude oil prices were low in 2015-16, the recycling industry struggled to compete with raw material production.

Nonetheless, recycling in general is the best of the three options.

But what about the plastic that is not recyclable — should we send it to landfill or incinerate? Here, the winner is less clear-cut. As we see across the range of studies above: it depends on context, plastic type and conditions as to whether landfill or incineration has lower impact in terms of greenhouse gas emissions or energy use.

Nara Loca Abadi is a recycled plastic specialist that promotes the use of recycled PET flakes, recycled PET chips, recycled PP & HDPE granules to various plastic and polyester manufacturers.