Plastic waste: better to burn?

08-26-2009: Burning plastic can give off less carbon dioxide than burying it, scientists claim in a Royal Society of Chemistry journal. Swedish scientists studied the CO2 produced when unrecyclable plastics are incinerated and the energy given off is recovered, compared with putting them into landfill.

The authors of the Energy and Environmental Science article, Ola Eriksson (University of Gävle, Sweden) and Göran Finnveden (Royal Institute of Technology, Stockholm, Sweden), initially disagreed on which of these methods of disposal would be lower in CO2 emissions.

Looking only at CO2 emissions, incineration of plastics produces a much greater amount of CO2 than landfill. However, in the special case when incineration is performed with high-efficiency energy recovery, it provides power normally generated by plants burning fossil fuels, and can produce less CO2 than would otherwise have been released into the atmosphere, making the overall process CO2-negative.

In Sweden, as in other European countries, the disposal of non-recyclable plastics in landfill is expensive and greatly discouraged, they prefer to incinerate it.

The researchers found the results surprising: “It showed we both were right,” said Eriksson.

These highly-efficient plastic incineration plants are not common throughout Europe and in most cases plastic incineration produces a high net emission of CO2.

Eriksson emphasises that they want European policy makers to think carefully about how they dispose of non-recyclable plastics. He wants them to “reconsider this policy to not put any plastic in landfill because, in some cases, it can be worth it,” he said.

Original article:Ola Eriksson, Energy Environ. Sci., 2009.