We previously put together a separate guide on the pros and cons of waste incineration in general.
However, in the interest of finding out the best way to dispose of plastic specifically, we’ve put together the guide below outlining the pros and cons of burning/incinerating plastic.
Summary – Pros & Cons Of Burning/Incinerating Plastic
When it comes to incinerating or burning plastic waste, some of the main potential benefits might be that it can be a way to generate energy from waste, it helps divert plastic from landfill sites, and it provides an option for cities with little land available for landfills.
On the other hand, some of the main potential drawbacks might be that it can involve the release of air pollutants and emissions, the cost of incineration or pyrolysis can be high, and burning plastic waste is not considered truly renewable.
Ultimately, there are different variables to waste management in each city or town
Not only should the type of plastic, and individual plastic items and products being managed as waste be taken into account, but the waste management systems and capabilities of the city or town in question should too
Every local government needs to do a waste management assessment to figure out the best solution to manage or dispose of plastic in their region, in terms of what is best from an environmental, social, and economic perspective, but also consider what is practical. The strategies and solutions might be different for each
Something we pointed out in our guide about potential solutions to plastic problems across society is that some strategies and solutions might have an added focus and might include reducing the waste rate of some plastics in the first place
Pros Of Burning/Incinerating Plastic
Burning plastic can generate energy, and this energy can have different uses and applications
Plastic waste can be burnt for energy at waste to energy facilities
There may be multiple uses and applications for the energy generated from burning plastic
In some instances the energy might be used for electricity, and in other instances it may be used for manufacturing products such as cement
Energy from plastic can … be used for applications like providing energy to manufacture cement (bbc.com)
Burning plastic waste for energy may be a direct substitute for burning fossil fuels for energy in some instances
Because of the stored energy in plastic, burning plastic at waste to energy facilities may in some instances be a substitute for burning fossil fuels directly for energy.
Plastic as a material may be more energy dense than coal
Different material have different energy densities (i.e. stored energy in their material structure)
This energy can be utilised when the material is burnt for the purposes of generating energy from waste
[Burning plastic can generate enough …] electricity for local grids in some instances (bbc.com)
[Plastic is energy dense …] Because it’s made of hydrocarbons like oil (nationalgeographic.com)
Burning plastic waste in general might address one of the biggest perceived problems with plastic
As a consequence of this, plastic waste might spend a long time in landfills, or out in the environment as a pollutant.
There’s also the issue that plastic can break down into microplastics.
Burning plastic may address some of these problems.
Admittedly though, it may only replace one set of problems with another, as there are still potential atmospheric pollutants, emissions and waste ash to manage
If plastic production rates and totals increase into the future, burning plastic waste may become a necessity in some places
More plastic being produced generally leads to more plastic waste being generated, and this plastic waste will have to be managed in some way
Incineration may become a necessity in some cities and towns to manage a % of the plastic waste in their waste stream
This may especially be the case in places that don’t have the capability to expand landfill capacity, or have issues with processing plastic at recycling facilities
Emissions and air pollutants from incinerators can be managed with different devices and technology
An incineration facility fitted with specific devices and technology can capture air pollutants and emissions from burning waste.
… toxic pollutants and compounds such as dioxins, acid gases, and heavy metals [… may be able to be captured with devices and technology like] scrubbers, precipitators, and filters … (nationalgeographic.com)
Bag rooms [also] bring [down] levels of pollution (treehugger.com)
Incinerator ash can be re-used or recycled, or simply treated and disposed of in a safe way
When plastic is burnt, it produces incinerator ash.
There may be re-use application for incinerator ash from burnt waste.
Alternatively, it may be able to be treated and disposed of in a safe way if the right processes are in place.
Pyrolysis may provide benefits that other waste to energy and incineration techniques for plastic don’t
Pyrolysis is one of multiple options for burning plastic, and it may have certain benefits over these other options.
[Pyrolysis …] has many benefits over conventional waste to energy and incineration, as well as over gasification
[For example …] it doesn’t emit air pollution contaminants … [and only emits] a small amount of CO2
[Additionally] … the by products of plastic pyrolysis [might be able to be] used for new high quality [plastic] material … [and this benefit might contribute in some ways to making plastic a more circular material]
Incineration of plastic might provide an option to manage contaminated or non recyclable plastic waste
Incineration might provide an option to manage some of these plastics apart from landfill
Incineration might provide at least a short term solution for country to country plastic import bans
For countries that already had or have incineration technology set up and running, bans on exports of their plastic to other countries might not impact them as significantly
China is an example of a country that implemented a plastic import ban in recent history
Cons Of Burning/Incinerating Plastic
Plastic is not yet a renewable resource
Plastic incineration does not remove the fact that plastic production itself has a sustainability footprint i.e. the footprint of plastic production does not disappear because the plastic ends up burnt
Additionally, not all incineration makes plastic a truly circular resource
Some groups and cities might ‘sell’ incinerating plastic as a complete solution to managing plastic waste, but, it might be a convenient solution for cities looking to take shortcuts, or, for those trying to profit from incentives in incineration related contracts and deals.
Several sources also indicate that incineration as it currently exists doesn’t contribute to a circular or sustainable society (pyrolysis can be the one exception to this though if the by products of plastic pyrolysis are used for new high quality material) (nationalgeographic.com)
Incineration technology can be expensive, and hard to scale
Not every city and country can afford more environmentally friendly or effective incineration technology.
There are upfront costs, and costs to scale the technology.
There can also be various challenges to scaling incineration technology. For example, incinerator plants need guaranteed/consistent streams of waste coming to them to be economically feasible to operate.
… a plant in Scandanavia spent a billion kroner to try to meet the European standards for dioxin [emissions] (treehugger.com).
Burning plastic isn’t always energy efficient
Although plastic might be an energy dense material, the efficiency of burning it might not be as good as other forms of energy generation.
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
Air pollutants from some incineration plants may degrade air quality and impact human health
If adequate air pollutant capture technology and devices aren’t installed, air pollution may be an issue at some incineration plants.
Additionally, pollutant capture technology might only work effectively in certain instances and when certain processes are implemented
Toxic pollutants such as dioxins, acid gases, and heavy metals can be an issue (nationalgeographic.com)
Some sources indicate US incineration plants don’t meet the environmental standards that some European ones do, nor do they have the latest pollution controls (treehugger.com)
Read more about waste incineration pollution, and ash control and management, in the thisiseco.co.uk resource
… pollutants can only be captured with sophisticated technology, and the technology is only useful if combustion plants are properly operated and emissions controlled (nationalgeographic.com)
Greenhouse gas emissions from some incineration plants might be an issue
Unless carbon capture technology and devices (or similar emission capture technology) is installed on incineration plants, greenhouse gas emissions might be an issue.
In 2016, U.S. waste incinerators released the equivalent of 12 million tons of carbon dioxide, more than half of which came from plastics (nationalgeographic.com)
When coal is phased out for generating electricity, incineration of unrecycled waste will be the most CO2-intensive form of generation (bbc.com)
Incineration ash might be hazardous and needs to be managed as a waste
Waste to energy and incineration plants have incinerator ash that needs to be managed, recycled or disposed of in an eco friendly and safe way
Incineration plants need processes in place t do this
Even pyrolysis has it’s potential problems
We listed some of the potential benefits to pyrolysis above in this guide, but several reports indicate that it coms with drawbacks at the moment.
Pyrolysis is an expensive and immature technology, and it is still cheaper to make diesel from fossil fuel than from waste plastic (nationalgeographic.com)
Recycling plastic can be better than incinerating plastic in some ways
There may be energy savings for example.
Studies have shown that recycling plastic waste saves more energy—by reducing the need to extract fossil fuel and process it into new plastic—than burning it … (nationalgeographic.com)
Some reports indicate that landfill is more eco friendly than incineration in some ways
In environmental terms, it is generally better to bury plastic than to burn it … [and there is the case to be made] that burying waste plastic in landfill is actually a cheap form of carbon capture and storage (bbc.com)
Some plastic problems might be best addressed by reducing plastic waste in the first place
Waste management options like burning plastic come into consideration only when plastic becomes waste.
But, as we’ve outlined in our guide about potential solutions to plastic problems across society, some of these solutions might require us to focus on producing less plastic waste in the first place.
Sending plastic to be burnt or incinerated may be only a second priority in comparison to some of these solutions.
1. Various other BMR guides on plastic and waste management