Burn or bury waste plastic?
Since China refused last month to accept any more foreign waste for recycling, the UK is facing a challenge.
How can it recycle more of its own waste? And should it bury or burn the low-grade waste that it can’t recycle?
We’re trying to answer the second question. And it certainly divides opinions.
So what are the facts about plastic waste?
Well, according to the HMRC’s UK trade info website, about 800,000 tonnes of plastic waste was exported from the UK for recycling to nations like China in 2014.
News reports suggest much of this was contaminated by other rubbish and had to be burned.
The UK itself was left with 1,244,774 tonnes of packaging sent either to landfill or incineration in 2016. The National Packaging Waste Database estimates that 1,015,226 tonnes of plastics packaging was recycled in 2016.
Remember, this is packaging, not all plastic waste.
So should we burn our hard-to-recycle waste, or bury it?
The case for burning
Here’s the case for burning.
Plastic is made from oil and gas, and it creates a lot of heat when it’s burned.
So, at first sight, it makes sense to harness that by burning it in an incinerator to make electricity.
It’s even more efficient if the incinerator can capture the waste heat from the process and use it to warm offices and homes.
Burning plastic this way currently substitutes in some places for burning dirty fossil fuels like oil or coal.
Mark Pawsey, the Conservative MP for Rugby, is chairman of the All-Party Group for the Packaging Manufacturing Industry.
He told the Commons: “Waste is used to generate the heat that enables the cement company based in my constituency to manufacture cement.
“That strikes me as a much better use of the calorific value of packaging than sending it to landfill.”
His argument is supported by the people who run incineration – the Environmental Services Association (ESA).
Its director Jacob Hayler told us: “It is better to recover energy from non-recyclable waste through (incineration) than send it to landfill.”
So what’s the case for burial?
Burning plastic creates harmful dioxins and if incinerators are inefficient, these leak into the environment. Modern incinerators are said to have largely solved this problem.
But climate change is another consideration.
The consultancy Eunomia says plastics burned in incinerators set up to generate only electricity create heat at 25% efficiency. This is much lower than the 55% efficiency for new gas-fired power stations.
Dominic Hogg from Eunomia told BBC News: “When coal is phased out for generating electricity, incineration of unrecycled waste will be the most CO2-intensive form of generation.
“This doesn’t make sense if the government’s trying to reduce CO2 emissions – unless the government takes drastic action to reduce the amount of plastic in unrecycled waste.”
Environment groups also fear that if the UK builds new incinerators to cope with the stockpile created by China’s rejection of waste plastic, the policy will lock in a demand for burning waste plastic that ideally should get recycled.
The government seems to have been persuaded by this argument. The environment minister Therese Coffey told the Commons: “In environmental terms, it is generally better to bury plastic than to burn it.”