Non-Recycled Plastics: A New Energy Resource

pyrolysis oil

Over the past few decades, recycling programs have expanded both in terms of communities served and what items can be recycled. Yet, despite progress, approaches to integrated waste management have only begun to evolve.

“While production and consumption are still dominated by a linear model, where goods are manufactured from raw materials, sold, used and then discarded, the growing population of middle-class consumers has created a rise in demand for good that’s challenging the sustainability of this system,” says Jeff Wooster, Global Sustainability Leader at Dow Chemical Company.

Today, the concept of a “circular economy” is rapidly capturing attention as a way to reconcile economic growth with environmental responsibility. “In fact, circular supply chains that increase the rate of recycling, reuse and remanufacture have the potential to generate more than $1 trillion a year by 2025,” says Wooster.

Plastic Pyrolysis Equipment
Waste Plastic Pyrolysis Equipment

In the U.S. we create about 254 million tons of trash each year. And while recycling programs have expanded, more than half all U.S. trash—approximately 134 million tons—ends up in landfills. According to the U.S. Environmental Protection Agency (EPA), almost one-fifth is from plastic items used every day, but aren’t recycled. “One key gap is the failure to address changes in the composition of the recycling stream and find a way to capture value from many of the materials that are growing in use, such as lightweight multi-material plastic packaging,” says Wooster.

However, emerging technologies offer solutions that divert non-recycled plastics from landfills and “recycle” them into feedstocks, valuable energy resources and other plastic products. In fact, if the U.S. took all the paper, wood, plastics, old clothes and other garbage that goes into landfills and converted them into useable energy, the U.S. could power nearly 14 million homes every year, according to the American Chemistry Council.

Non-recycled plastics as an energy resource

Believe it or not, plastic is a valuable energy resource. And, through energy recovery, companies can recover the embedded energy content of this valuable resource.

Through a collaborative effort to explore an alternative for plastic waste, Dow co-sponsored a three-month pilot program in Citrus Heights, Calif., with Agilyx to convert non-recycled material and low-value plastics collected in purple bags into a high-value synthetic fuel.

And according to a recent report by the Flexible Packaging Association, if recycling programs like Dow’s Energy Bag Pilot were implemented across the U.S., we could keep more than 4 million tons of plastic waste out of landfills, enough to produce one billion gallons of fuel every year. Additionally, the American Chemistry Council reported making synthetic crude oil from plastics reduces greenhouse gas emissions by 60 to 70% compared to conventional extraction of crude oil.

“Our Energy Bag Pilot used pyrolysis to convert non-recycled plastics into 512 gallons of synthetic crude oil, recovering nearly 12 barrels of oil, but other recovery technologies can also be used to capture the energy value of plastics,” says Wooster.

Pyrolysis is a resource recovery technology that uses heat in the absence of oxygen to chemically transform plastic into end products, including synthetic crude oil, synthetic wax and syngas. The crude oil can be further refined and made into valuable products for everyday use such as gasoline, diesel fuel, jet fuel, fuel oil and lubricants. It can even be transformed back into plastic.

“Energy recovery technologies like pyrolysis (waste plastic to oil) are complementary to mechanical recycling because they allow value to be captured from additional materials,” says Wooster. “Many materials that can’t be easily recycled provide other lifecycle benefits which lead to their selection for use, and those materials have an embedded energy value even after they have served their primary function.”

pyrolysis oil
pyrolysis oil

Yet, a key challenge for any recovery process, whether energy recovery or mechanical recycling, is collecting a sufficient quantity of materials to provide the scale needed for beneficial economics. Due to plastic’s light weight, it takes combining materials from many households to provide enough material to make their collection and processing worthwhile.

“Since there isn’t an established infrastructure supporting the recovery of plastic for energy, new programs must fit within the constraints of existing recycling and municipal waste management systems,” says Wooster.

The Energy Bag Pilot

The idea of a collection pilot has been a few years in the making, according to Wooster. And Dow has been actively reviewing new energy-recovery technologies, and analyzing the quantity and quality of non-recycled plastics available for recovery.

In 2014, Dow partnered with Republic Services and they connected the City of Citrus Heights, allowing Dow to have a resource management expert and an engaged community to start the pilot. Agilyx had a pyrolysis facility located relatively close to Citrus Heights and accepted the invitation to process the materials from the pilot. The pilot was also supported by Reynolds, the Flexible Packaging Association and the American Chemistry Council. “It’s extremely exciting to have organizations working together to find solutions for current challenges,” says Wooster.

During the three-month pilot program in Citrus Heights, which included six collection cycles, neatly 8,000 purple Energy Bags were collected; approximately three tons of non-recycled items diverted from landfills; and 512 gallons of synthetic crude oil produced from the conversion.

“There was a strong level of citizen participation, with 30% citizen participation in the pilot,” says Wooster. “The city’s leadership was enthusiastic in their support of the pilot program because they saw the value in the opportunity offered by this program to divert more materials from landfills, and 78% of citizens said they would be likely to participate if given another chance.”

The key result of the pilot program proved that non-recycled plastic items—like juice pouches, candy wrappers and plastic dinnerware—could be collected and converted into an energy resource.

The future energy benefits

The Energy Bag Pilot Program is just a first step towards changing the way the U.S. handles waste. “We will share the success of the pilot with the industry and other communities with the hope that municipalities and industry stockholders will adopt programs like Energy Bag to move the potential for large-scale plastics-to-energy conversion forward,” says Wooster.

In an effort to achieve this, Dow recently announced ambitious 2025 Sustainability Goals.

“The Energy Bag Pilot is a story about the power of collaboration—how companies, communities, organizations and everyday people can work together to make the changes the world wants to see—and that’s what we hope the industry takes away from this,” says Wooster.

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