USING END OF LIFE PLASTICS AS FEEDSTOCK FOR ADVANCED CHEMICAL RECYCLING

Sustainable Development Goals

Organizations Involved:
Dow Chemical, Flexible Package Association, Republic Services, Agilyx, Reynolds Consumer Products, American Chemistry Council, Citrus Heights, California 
Services:
Feasibility Study, Due Diligence, Supply Chain Management

The Challenge:

Plastic production has soared since it became commercially produced more than 50 years ago and is now ubiquitous in daily life. It is found in virtually all products, from packaging and vehicles to medical equipment and electronics. This growth has seen plastic become one of the biggest environmental issues worldwide, with plastic waste polluting land, oceans, air, and even food and human blood. The United States is a major contributor to this growing problem, as one of the world’s largest consumers of plastics.

Plastic waste has numerous negative environmental and health impacts, though the most concerning to Americans is the impact plastic pollution has on marine life. Large amounts of plastic waste leak into the ocean every year, contributing to the deaths of thousands of sea mammals and fish. Because of this, there is considerable frustration with the recycling systems in the United States due to how much plastic waste ends up in the ocean. Some of the most common waste items found along beaches across the country are plastic products such as food wrappers, grocery bags, straws and stirrers, and beverage bottles.

In the United States, the use of plastics has roughly tripled since the 1980s to more than 80 million metric tons annually, of which the vast majority of this volume end up as waste. In 2019, total plastic waste generation reached 73 million metric tons, equivalent to 221 kilograms of plastic waste per inhabitant. This was roughly five times more than the global per capita average. With plastics demand showing little signs of slowing down, plastic waste generation is projected to grow to 142 million metric tons by 2060. Plastics account for roughly 12 percent of municipal solid waste generation, with plastic containers and packaging the main source of plastic waste. Of the estimated 80 million tons of municipal plastic waste generated in the United States in 2021, at least 85 percent was sent to landfill sites. Despite plastic waste generation soaring, the recycling rate is falling. Only five to six percent of municipal plastic waste was recycled in 2021, compared with almost nine percent in 2018.

Although municipal plastic waste generation has increased five-fold since the 1980s, the country still doesn’t have the capacity to recycle all its waste domestically. Therefore, every year the country relies on the exportation of large volumes of plastic waste to be treated in other countries around the world where it is unknown what happens to the waste plastics once it leaves the United States. What is ridiculous is that these exports count towards domestic recycling rates even though shipments often go to developing countries that lack efficient waste management infrastructure. This means waste is often open-dumped or burned, exacerbating the already considerable plastic waste problem. As China restricted foreign waste imports alongside other countries, the United States' plastic waste exports have fallen in recent years, and in 2021 shipments dropped to 0.6 million tons. This has put further strain on the already struggling recycling system.

The Solution:

Currently, most multi-material flexible plastic packaging and many other types of plastics are difficult to mechanically recycle and end up in landfills. There are, however, emerging technologies that can offer solutions for diverting them from landfills and “recycling” them into feedstocks or valuable energy resources.

During the course of 2014, The Dow Chemical Company, Republic Services, The Flexible Packaging Association, Reynolds Consumer Products, and the city of Citrus Heights, California, collaborated to implement a first-of-its-kind pilot in the United States. The “Energy Bag Pilot” tested the feasibility of collecting households’ non-recycled plastics ("NRP") at the curbside, sorting the NRP at a material recycling facility ("MRF"), delivering the desired/sorted-out NRP to an energy conversion facility, and effectively converting that NRP into an energy resource – all via an existing waste management infrastructure.

During this pilot (conducted between June 1-August 31, 2014), citizens of Citrus Heights living in single-family dwellings were asked to place their non-recycled plastics into a provided bright purple bag (called the “Energy Bag”) and, when full, to place the bag inside their recycling bin at curbside for the regular bi-weekly recycling collection.

At the Republic Services Newby Island Resource Recovery Recyclery (the material recycling facility/MRF), Energy Bags were separated from the regularly recycled items, bundled, and shipped to a pyrolysis facility where these high-energy-content materials were converted into valuable synthetic fuel oil.

The pilot program sought to answer five specific questions:

  • Will people participate?
  • Will people follow the provided instructions and place the recommended NRP inside the Energy Bag?
  • Can the NRP be effectively collected using the existing curbside recycling infrastructure?
  • Can the NRP be effectively sorted at the recycling facility?
  • Is the NRP collected suitable for pyrolysis?

The answers were encouraging, and a summary is as follows:

  • A post-pilot survey reported that 1/3 of targeted households participated at some point during the pilot. The pilot resulted in nearly 8,000 Energy Bags collected totaling approximately three tons of material.
  • The majority of participants followed the provided instructions well, resulting in contamination rates comparable to a typical recycling collection cycle. The pilot’s contamination rate was 16.5%.
  • Collecting the bags with other recyclables was effective and not disruptive to the haulers’ collection routines. The provided instructions asked that the Energy Bags be placed inside the recycling bin.
  • Manually pulling the Energy Bags during the pre-sort phase at the recycling facility was very effective, and only a few bags made it past the pre-sort station. No Energy Bags were found wrapped in the paper screens. The recycling facility management indicated that the pilot ran seamlessly.
  • Typical maximum oil conversion efficiencies for pyrolysis are 70-80%. The NRP collected was suitable for pyrolysis and tested at 58% oil conversion efficiency. The Energy Bag Pilot fulfilled its premise through a conversion of 512 gallons of synthetic fuel oil.

The pilot ran for three months; however, the planning, negotiations, pre-production, pre-pilot promotions, and post-pilot data recovery stretched over the course of a year. The planning, implementation, and completion of this pilot were possible because of the strong coalition of partners.

The complete results of the Energy Bag Pilot are available in the following report, and the desire is that other municipalities and industry stakeholders will adopt programs like this one to move the potential for large-scale “plastics-to-energy” conversion forward.

As a next step, another pilot program is being planned to validate the findings and assumptions generated by this pilot. Plans anticipate collaborating with brand owners, packaging converters, and industry associations with broad knowledge regarding plastics, sustainability topics, and consumer marketing to help solve issues encountered in this initial pilot.

The Outcome:

The Citrus Heights Energy Bag Pilot sought to demonstrate the viability of a curbside municipal resource recovery system for currently non-recycled plastics using an existing waste management infrastructure. Ultimately, the collected materials were used as feedstock for conversion into synthetic fuel oil, thus “closing the loop” of the plastics’ life cycle.

The targeted plastics covered a wide range of items, but multi-material plastic packaging (e.g., pouches for food and beverage packaging applications) represented a large percentage. Current estimates by the EPA suggest these types of plastic packages not targeted for recycling account for about 5MM of 250MM tons or 2% of all municipal solid waste.

Critics argue that turning plastics and other organics into energy or fuel destroys valuable resources and may reduce incentives for mechanical recycling. Countries in Europe, however, have some of the highest recycling rates in the world (up to 70%), yet also turn their residual waste, including a lot of flexible packaging, to energy and avoid landfilling.

In addition, recent North American research has documented that the states with relatively high recycling rates for plastics are also the ones with the most waste-to-energy capacity. This shows that there is a great opportunity before us – that different options for landfill diversion are already being embraced, and programs being tested, such as this Energy Bag Pilot, could offer another valuable method to make the most out of these resources and protect our environment.

This pilot was successful because it answered all the questions posed and clearly demonstrated the viability of an alternative municipal waste management program to divert NRPs from landfills and convert them into valuable resources. Specifically, it showed:

  • Multi-material flexible plastic packaging and miscellaneous non-recycled plastic items can be collected at the curbside and integrated into an existing recycling program.
  • The public can follow instructions and provide a good source of plastics for energy conversion.
  • Contamination levels can be controlled.
  • The bags can make it through the collection and material handling equipment.
  • Sorting out and consolidating the bags can be efficiently managed at a recycling facility with enough space to accommodate additional manual sorters and temporary storage of the Energy Bags.
  • Sorted materials can be transported and are suitable to be converted into a new energy resource.
  • A strong partnership among the coalition partners ensures all aspects of the program are successful. Moving forward, it is important to continue to prove the viability of recycling non-recycled flexible packaging and plastics into energy resources.

Therefore, a long-term pilot program needs to be undertaken to increase participation rates and generate the volume of plastic required to justify the operation of a conversion technology facility. In the long term, it may not fall entirely on Energy Bag content to support the conversion facilities. Recycling facilities sell a significant amount of their collected materials such as paper, metal, aluminum, recycled plastics, etc. to recyclers, but there are currently no resale markets for these non-recycled plastics. Many recycling facilities already have many types of non-recycled plastics going down their lines that would likely be intentionally collected if a profit could be made. Capturing a portion of this existing material, along with the NRP collected through the Energy Bags, could help fill the needs of a conversion technology plant like Agilyx. Looking to the future as the supply of collected plastics grows and the ability of recycling facilities to sort and market more specific types of plastic develops, conversion technologies could expand and evolve to provide additional outlets for resource recovery of a wider range of plastics.

As a next step, another pilot is being planned to validate the assumption that improved communication will drive higher participation rates and higher quality of material collected for conversion. Plans anticipate partnering with brand owners with a great understanding of consumer marketing, packaging converters, and industry associations with knowledge regarding plastics, sustainability topics, and complementing strategies to help solve issues encountered in this initial pilot. Any subsequent pilots will continue to be implemented by a broad coalition of industry players to ensure success and continue to drive change.

The Energy Bag Pilot was, and continues to be, a story about the power of collaboration – how companies, communities, organizations, and everyday people can work together to make the changes that the world wants to see.

Klean Industries Inc., a specialist in petroleum-based waste recycling, started working with Dow Chemical in 2009 and facilitated site visits with Dow Chemical to one of its largest reference facilities in Japan. Klean and its partners continue to explore potential opportunities to expand upon the knowledge and experience gained throughout various pilot studies across North America and continue to develop new opportunities to roll out facilities In North America that incorporate Klean's technology that has been proven at scale in Japan. 

For more information on Klean's relationship with Dow Chemical, please see the following news release >> GO.

This project addresses the SDGs by taking into account the following goals and associated targets. It contributes to ensuring sustainable consumption and production patterns by coming up with a sustainable waste treatment framework (Goal 12). Through a safe and inclusive waste disposal system, the SDG strives to protect ecosystems and prevent biodiversity loss (Goal 15).