Plastic must be removed from waste sent to incinerators through mechanical pre-treatment and increased recycling to reduce the carbon impacts of waste incineration, according to a new report from Eunomia Research & Consulting.
The report, commissioned by ClientEarth and entitled ‘Greenhouse Gas and Air Quality Impacts of Incineration and Landfill’, suggests that waste incineration as a form of electricity generation produces more carbon emissions per kilowatt hour than the new, lower carbon sources of electricity coming onto the national grid – 504 grammes of CO2 per kilowatt hour of electricity generated (gCO2e/kwh), compared to 270 gCO2e/kWh.
The disparity is only expected to grow as the UK’s electricity mix continues to decarbonise, says Eunomia, with the carbon emissions produced by new national grid sources of electricity projected to fall to 66 gCO2e/kWh by 2035, while those produced through waste incineration are expected to increase to 527 gCO2e/kWh.
Energy from waste
The use of waste incineration for energy recovery has increased in recent years, driven by a need to reduce waste sent to landfill and provide a low-carbon alternative to energy generated from fossil fuels.
Eunomia says that the decarbonisation of the UK’s energy supplies and increasing amounts of fossil-based plastic as a proportion of residual waste mean incineration can ‘no longer be considered a low-carbon form of energy’.
The amount of food waste in residual waste is expected to fall as separate collections of food waste are introduced across England over the next decade, which will leave a higher proportion of plastic, according to Eunomia – expected to reach 17.1% by 2035, in the residual waste stream, a large part of which Eunomia says will be plastic film, which is not readily collected or recycled by local authorities.
To achieve the UK’s goal of becoming a net-zero carbon emitter by 2050, all sectors of the economy must take action to reduce their carbon emissions
To reduce the carbon impact of incineration facilities, plastic waste present in the residual waste stream ‘must be removed’, it says, either through mechanical pre-treatment or through better source separation of plastic waste for recycling.
Failure to do so could see the climate performance of incineration ‘become worse than landfill by 2035’, it says – emissions from landfill are expected to fall due to higher recycling targets driving organic waste and paper out of residual waste – and make it increasingly challenging for the waste sector to achieve the government’s 2050 net-zero target.
Ann Ballinger, Principal Consultant at Eunomia, said: ‘As recycling improves, the carbon intensity of incinerators is set to increase over time as the proportion of plastics in the residual waste feedstock increases.
‘To achieve the UK’s goal of becoming a net-zero carbon emitter by 2050, all sectors of the economy must take action to reduce their carbon emissions. For waste incineration, this means focusing on plastics recycling to remove fossil carbon from the feedstock heading to incineration facilities, if such facilities are to achieve a net-zero waste management system.’
Net zero targets
Eunomia says incineration in particular will be ‘incompatible’ with the government’s 2050 net zero target unless widespread implementation of carbon capture and storage (CCS) is achieved.
Trials are currently being undertaken by incineration companies, but the technology is ‘not yet commercially viable’, Eunomia says, and will ‘considerably increase’ the cost of waste management.
It also says that incineration still poses a risk to air quality, despite modern incineration facilities being fitted with controls to significantly reduce air pollution. It says they ‘still emit harmful nitrogen oxides and particulate’ – tiny particles produced by the incineration of material – which contribute to air quality impacts.
The company says this ‘underlines’ the need for greater emphasis on recycling, reuse and waste prevention to reduce the amount of waste sent for incineration.
ClientEarth lawyer Tatiana Luján added: “As the world drowns in plastics and countries like China close their doors to foreign waste, incineration will increasingly be pushed as an ‘easy’ alternative.
“But waste does not just disappear in a puff of smoke. The more waste and plastics are sent to be burnt, the more our environment and health will suffer in parallel.”
The Environmental Services Association (ESA) says it questions some of the assumptions and figures in the findings, but some of the messages are consistent with the direction of travel due to be set out in its forthcoming net-zero carbon strategy.
Executive Director of the Environmental Services Association (ESA), Jacob Hayler, said: ‘Although we question some of the assumptions and figures in Eunomia’s report, some of its messages are consistent with the direction of travel due to be set out in the ESA’s net-zero carbon strategy.
‘Our sector already plays a significant role in helping the wider economy to reduce carbon emissions, but we recognise that we must also reduce the carbon-intensity of our processes to play a greater role in helping the UK to achieve net zero emission before 2050.
Our sector already plays a significant role in helping the wider economy to reduce carbon emissions, but we recognise that we must also reduce the carbon-intensity of our processes to play a greater role in helping the UK to achieve net zero emission before 2050
‘Diverting organic material from landfill and removing plastics from energy recovery are essential components of this strategy in the shorter term, but efforts to remove plastics from the residual waste stream should first be focussed on upstream interventions to minimise the volume and maximise the recyclability of plastics placed on the market, rather than on trying to “fix” the problem once low grade plastics are mixed with other post-consumer residual waste.
‘In the longer term, ahead of 2050, improving the efficiency of energy recovery through heat networks and implementing carbon capture and storage solutions will also be necessary to achieving a net-zero recycling and waste management sector.’
The ESA have produced a ‘frequently asked questions’ briefing on recovering energy from waste.