Note: This article continues the series of updates in Plastics Engineering from Plastics Make it Possible®, an initiative sponsored by America’s Plastics Makers® through the ACC.
Plastics recycling in the USA has been growing year-over-year since we began measuring in the early 1990s. That’s good news for the environment. However, like other materials, it’s unlikely we ever will be able to recycle all used plastics.
So what do we do with used plastics that cannot be recycled?
The molecules that make up plastics are composed mainly of carbon and hydrogen, so burying used plastics in landfills is a waste of resources. That’s one reason some U.S. communities convert their non-recycled garbage (plastics and other combustibles) into energy.
Today’s 80+ waste-to-energy facilities divert roughly 17% of post-recycled garbage from the U.S. waste stream, producing enough electricity to power approximately two million homes. The energy potential from greater diversion of just plastics is quite large. Engineers at Columbia University found that converting all non-recycled plastics to energy could power 5.7 million homes. Converting all post-recycled garbage to energy could power nearly 14 million.
Today, a growing number of technologies promise to recover an increasing portion of the energy from used plastics. Typically called “plastics-to-fuel,” the technologies convert plastics into useful fuels or into feedstocks for new products. The energy value of plastics is recovered to be used again—rather than buried.
The products of plastics-to-fuel (PTF) vary, but the process usually involves these steps:
- First, plastics are collected and sorted for recycling, and the plastics that don’t have strong demand in commercial recycling markets are shipped to a PTF facility.
- These plastics are heated in an oxygen-free environment, where they melt into a liquid and then vaporize into gases.
- The gases are cooled and condensed into a wide variety of useful products, such as oils, fuels, and petroleum products.
- PTF producers sell the petroleum products to manufacturers and industrial users, while fuels are used to power cars, buses, ships, and planes.
These evolving technologies are capable of producing a wide variety of products that can be sold into numerous industries, helping to strengthen and expand the opportunities to divert even more plastics from landfills.
PTF technologies hold enormous promise: If all the non-recycled plastics in the USA were converted this way, we could create enough fuel to power nine million cars for an entire year.
In addition, the economic opportunities are significant. An economic analysis determined that by tapping the potential of non-recycled plastics, the USA could support hundreds of PTF facilities and generate tens of thousands of jobs, resulting in billions of dollars of economic output (although the fluctuating price of oil could impact these figures).
These technologies complement ongoing recycling efforts by recovering energy from used plastics that are not recycled in commercial markets. One example: as part of sustainability efforts, consumer product companies increasingly are turning to lightweight plastic pouches for packaging their goods. This type of packaging is highly efficient in its use of resources and generates very little waste. But it’s typically not included in recycling programs. Increased utilization of PTF technologies could help reduce the amount of this packaging and other non-recycled materials sent to landfills, while generating jobs and products that help power local economies.
Reduced Carbon Intensity/Emissions
The carbon intensity of producing energy using PTF technologies is roughly one-third that of traditional crude extraction. And it’s roughly one-sixth that of certain new sources of crude oil, such as oil sands or shale oil. Plus, the production of PTF energy also displaces the need for equivalent amounts of crude oil extraction.
In addition, a 2012 study by RTI International (“Environmental and Economic Analysis of Emerging Plastics Conversion Technologies”) found that a “[l]ife–cycle environmental review shows that waste conversion technologies have significant environmental benefits in energy saved and greenhouse gases averted compared to landfill disposal.”
Another potential environmental benefit of plastics-derived fuels could be cleaner-burning fuels, due to the low sulfur content of plastics. The main product of these technologies is a liquid fuel that can be refined into a cleaner-burning diesel fuel. Reducing sulfur content in diesel used for boats, machinery, generators, and vehicles could help promote clean air.
Technical & Economic Barriers Falling—but Some Remain
PTF technologies are not new, but until recently they have moved forward slowly in fits and starts. As a 2011 research project (“Conversion Technology: A Complement to Plastic Recycling”) by 4R Sustainability, Inc. notes: “The technology has existed for decades, but challenges seemed to persist in making commercial-scale systems economically feasible, and the technology was limited. … However, recent investment and innovation in pyrolytic technology has created a new generation of systems that may overcome these previous challenges.”
The RTI study also found that changing economic realities are making PTF technologies a more affordable choice, compared to traditional waste disposal. The study concluded that “waste conversion technologies are already able to produce fuel outputs at lower costs than landfill disposition in some regions.”
But to be sure, barriers remain, as RTI International pointed out:
- Outdated regulations that treat an energy-laden feedstock—used plastics—like waste have stymied progress and the acceptance of this technology in certain states.
- Reliable sources of feedstocks for PTF facilities—namely, used plastics—must be secured.
Deploying & Leveraging PTF Technologies
Fortunately, companies that deploy PTF technologies have worked hard to overcome these and other barriers. Among others, the core member companies of the Plastics-to-Fuel & Petrochemistry Alliance (Agilyx, RES Polyflow, Vadxx Energy) develop and implement technologies that convert non-recycled plastics into petroleum-based products.
And these companies are expanding. For example, in December 2014, RES Polyflow announced plans for a new facility in Ashley, Indiana, designed to produce 17 million gallons (64 million L) of ultra-low sulfur diesel and gasoline “blendstocks” annually, by converting 100,000 tons of used plastics. The first phase of the project is expected create 136 full-time jobs when completed. RES Polyflow estimates the second phase will double the capacity by 2021. The company also plans to build other facilities in surrounding Midwest states.
As barriers fall and technologies advance, PTF technologies also have the potential to significantly improve waste-management practices—particularly in regions of the world with rapidly emerging economies, on densely populated coastlines, and where waste-management practices have not yet caught up with growing consumption. When communities realize the value inherent in used plastics (and other materials), they have more incentives to divert these materials from the waste or litter stream to capture their value.
PTF technologies have become increasingly scalable and can be customized to meet the needs of various economies and geographies. In 2014, the American Chemistry Council’s Plastics Division and the Ocean Recovery Alliance joined forces to disseminate practical data on PTF technologies globally. The two organizations created tools designed to help potential investors, developers, and community leaders determine whether these technologies could help meet relevant waste-management needs and demand for PTF products. These no-cost tools review the available commercial technologies, operational facilities, and other facets needed for a business plan.
For more information on PTF technologies, visit the American Chemistry Council’s web site: www.americanchemistry.com.