- Plastic-to-fuel (PTF)
- Thermal recycling
- Thermal cracking
- Catalytic cracking
- Chemical recycling
- Waste to energy
- Mechanical or conventional recycling
- Circular economy
Plastic-to-fuel (PTF) processes use heat, pressure, and/or chemical solvents to break plastic waste down into liquids or gases that can be burned as fuel. The term is often misleadingly categorized as “chemical recycling,” a process that uses similar methods to break plastic waste down into constituent parts that can be made into new plastic. But while some of the same technical processes are used in both treatments to break down plastic waste, if the end product is ultimately burned, the treatment is plastic-to-fuel.
Bans & Restrictions
There are currently no plastic-to-fuel bans, but some legislation, like the European Union’s Waste Framework Directive, prohibits PTF from being counted as “recycling.”((Directive 2008/98/EC of the European Parliament and of the Council on waste and repealing certain directives. OJ L 312 22.11.2008, p. 3. http://data.europa.eu/eli/dir/2008/98/2018-07-05)) The state of Rhode Island has also banned high-heat treatments (i.e. pyrolysis and gasification processes like those used for PTF) of medical waste, including plastic medical waste.((The High-Heat Medical Waste Facility Act of 2021. 2021 — H 5923 Substitute A as amended. State of Rhode Island General Assembly. http://webserver.rilin.state.ri.us/BillText/BillText21/HouseText21/H5923Aaa.pdf))
By turning plastic waste into fuels to be burned, plastic-to-fuel fundamentally does nothing to reduce plastic waste production or decrease the need for new plastic. At the same time, it produces significant greenhouse gas emissions by turning fossil fuel-based plastics into CO2 and air pollutants. Overall, PTF suffers from technical, economic, and environmental challenges that threaten its own viability as well as the climate and human health.
Despite decades of development, plastic-to-fuel’s biggest challenge is its basic technological viability. A highly complex process, PTF faces many technical challenges including:
- Limitations on the types of plastics that can be processed
- The sorting and cleaning of contaminated plastic waste feedstock
- Temperature control during conversion processes
- Removal of impurities from end products
- Management of toxins present in resulting waste residues
These issues have led PTF facilities to fall short on projected energy and revenue generation, miss emission targets, sustain corrosive damage to building structures, and even suffer fires and explosions.((Zero Waste Europe. (2015). Air Pollution from Waste Disposal: Not for Public Breath. ZWE. https://zerowasteeurope.eu/downloads/air-pollution-from-waste-disposal-not-for-public-breath/))((Rollinson, A. N., Oladejo, J. M. (2019). ‘Patented blunderings’, efficiency awareness, and self-sustainability claims in the pyrolysis energy from waste sector. Resources, Conservation and Recycling, 141, 233-242. https://doi.org/10.1016/j.resconrec.2018.10.038))((Gleis, M. (2012). Gasification and Pyrolysis – Reliable Options for WasteTreatment? Waste Management, 3, 403-410.))((Rollinson, A. N. (2018). Fire, explosion and chemical toxicity hazards of gasification energy from waste. Journal of Loss Prevention in the Process Industries, 54, 273-280. https://doi.org/10.1016/j.jlp.2018.04.010))((Tangri, N., Wilson, M. (2017). Waste Gasification & Pyrolysis: High Risk, Low Yield Processes for Waste Management. Global Alliance of Incinerator Alternatives. https://www.no-burn.org/gasification-pyrolysis-risk-analysis)) An expert review of the available evidence on the technology in 2020 concluded that PTF is technologically immature, unsustainable, and presents a risk to potential investors,((Rollinson, A., Oladejo, J. (2020). Chemical Recycling: Status, Sustainability, and Environmental Impacts. Global Alliance for Incinerator Alternatives. https://doi.org/10.46556/ONLS4535)) a statement that is reflected by the fact that over $2 billion has been spent on failed or cancelled gasification or pyrolysis (the processes required to break down plastic waste) facilities in the US as of 2017.((Tangri, N., Wilson, M. (2017). Waste Gasification & Pyrolysis: High Risk, Low Yield Processes for Waste Management. Global Alliance of Incinerator Alternatives. https://www.no-burn.org/gasification-pyrolysis-risk-analysis))
All of the above technical challenges drive up cost and risk for PTF facilities, adding an economic barrier to its further development. To make up for this, PTF companies sometimes seek government subsidies, and to date in the US has spent over $450 million in taxpayer dollars to fund such projects.((Schlegel, I. (2020). Deception by the numbers: American Chemistry Council claims about chemical recycling investments fail to hold up to scrutiny. Greenpeace. https://www.greenpeace.org/usa/research/deception-by-the-numbers/)) In this way, PTF poses the additional risk of sapping much-needed resources that could be spent on the development of other, more viable solutions to the plastics crisis.
Moreover, by converting plastic waste into fuel for combustion, PTF effectively turns plastic waste into carbon dioxide and air pollutants, increasing the overall environmental impact associated with plastic production. Robust life cycle assessments and data from a US PTF company indicate that the carbon dioxide emissions associated with the fuel resulting from PTF processes are at least as carbon-intensive as conventional fossil fuels.((Šerdoner, A. (2020). Counting Carbon: A Lifecycle Assessment Guide for Plastic Fuels. Bellona, Rethink Plastic, Zero Waste Europe. https://zerowasteeurope.eu/library/counting-carbon-a-lifecycle-assessment-guide-for-plastic-fuels/))
Toxic emissions from PTF end-products are also worse than those resulting from burning conventional fuels: diesels and waxes produced from PTF processes contain more toxic residues, dioxins, persistent organic pollutants (POPs), and PAHs (a class of compounds that could cause liver and kidney damage or cancer), than conventional diesel, and their burning produces more air pollutants like NOx, soot, and carbon monoxide than regular diesel.((Rollinson, A., Oladejo, J. (2020). Chemical Recycling: Status, Sustainability, and Environmental Impacts. Global Alliance for Incinerator Alternatives. https://doi.org/10.46556/ONLS4535))
The cleaning process to remove these toxins from PTF end-products is difficult and expensive, and creates more environmental impacts, barriers to implementation, and additional toxic waste streams.((Rollinson, A., Oladejo, J. (2020). Chemical Recycling: Status, Sustainability, and Environmental Impacts. Global Alliance for Incinerator Alternatives. https://doi.org/10.46556/ONLS4535)) Moreover, the treatment plants that handle and generate said toxic materials are often sited in environmental justice communities, that is, indigenous, low-income communities, and/or communities of color that are disproportionately exposed to industrial emissions.((Patel, D., Moon, D., Tangri, N., Wilson, M. (2020). All Talk and No Recycling: An Investigation of the U.S. “Chemical Recycling” Industry. Global Alliance for Incinerator Alternatives. www.doi.org/10.46556/WMSM7198)) The toxic legacy of PTF processes is compounded in lower-income countries that often lack laboratory infrastructure to monitor chemical emissions and the regulatory frameworks to monitor and enforce emission standards.
Finally, PTF projects are expensive and require substantial financial investment. This can create a ‘lock-in’ effect, whereby the reliable delivery of feedstock (plastic waste) is essential to secure the pay-back on that investment. Often, this is secured through “deliver or pay” contracts that demand continued delivery of plastic waste, hampering efforts to improve plastic reduction, reuse, and recycling.
Plastic-to-fuel is a demonstrably risky technology that exacerbates environmental and social problems rather than solves them. It has no role to play in solving the plastics crisis.