Dow Chemical adding “Recover” to “Reduce, Reuse, Recycle”

By: 
January 24, 2013


Jeff Wooster, Dow's global sustainability leader for plastics, is very aware of the impression some have about plastic packaging.

"We understand that some consumers view packaging as waste," he told PlasticsToday. "We want to help consumers feel good about plastic packaging and have them know when they're done with it, the packaging will be reused."

Dow Chemical believes in order to achieve 100% recycling of packaging, the industry must progress from the 3R mindset, which is the widely practiced "Reduce, Reuse, Recycle," to the more comprehensive efforts being used in regions such as Europe that add the fourth "R" for end-of-life materials—"Reduce, Reuse, Recycle and Recover." Dow says using an integrated 4R approach will help assure greater total value recovery from end-of-life plastics and other used materials.

Energy recovery takes end-of-life plastics through a conversion process and uses the resulting energy value as a fuel. The combustion method of energy recovery is also known as thermal recycling, and is referred to as "recycle-to-energy" (RTE) within Dow. Many believe that energy recovery can create a valuable alternative energy source but at the same time reduce dependence on natural gas, oil and coal.

While the first option for the recovery of many plastics is mechanical recycling, Wooster said in order to increase the overall recovery of plastics there must be an integration of recycling with chemical transformation and energy recovery.

Wooster said some throw up red flags when it comes to energy recovery because they believe it will divert material from being recycled.

"The key is understanding how energy recovery works as a system because mechanical recycling and energy recovery can work together," he said. "We have the potential to recycle and recovery energy from a large amount of material."

Mechanical recycling is primarily intended for larger volume treatment of mono-materials, such as PET and HDPE bottles, but Dow says there are limitations in terms of technology, logistics, costs and infrastructure. Energy recovery programs can capture value from consumer goods packaging along with non-recycled stretch and shrink film. Specifically, polyethylene, polypropylene, and polystyrene are said to have high material energy values.

"While it makes economic sense to recycle materials, there are a lot of packages that can't be easily recycled," Wooster said. "The best thing to do in that case is recover the energy."

Dow has experience with energy recovery. In 2010, Dow conducted an energy recovery trial in North America that the company says successfully demonstrated that used plastic can generate energy. The pilot test, conducted at a rotary kiln in Dow's Michigan operations, found that 96% of available energy was recovered after 578 lb of used linear low density polyethylene was thermally recycled. The energy recovered was equivalent to 11.1 million BTUs of natural gas and was used as fuel for Dow's incinerator during the test.

In 2011, six additional energy recovery trials were conducted using non-recycled plastics (NRPs) from Dow Michigan operations to displace natural gas. These trials used 100 tons of NRPs and saved 2 billion BTUs of energy.

In addition, the American Chemistry Council and the Flexible Packaging Association are also actively working to validate the energy recovery prospects for plastics. Both organizations are investing in energy recovery trials.

Slow start, but growing interest

There are 2150 thermal waste treatment plants currently operational around the globe and those facilities have the capacity to treat almost 250 million tons of waste per year, according to a report by the German environmental consultancy, Ecoprog.

Between 2007 and 2011, the worldwide installed annual capacity increased by about 12%. This growth will increase in the next five years and Ecoprog estimates the annual capacities will increase by 21% by 2016. By then, operational capacities will amount to about 300 million annual tons.

About 250 new waste-to-energy plants will start operations by 2016. The group said that Europe continues to lead the market with Asia close behind.

Ecoprog said for the first time in several years, new waste-to-energy projects are currently being implemented in North America. It is uncertain, however, whether this will result in a stronger waste-to-energy market in North America for the long term, the group said. There are about 80 waste-to-energy facilities across the country.

While it's been a slow start for North America, Wooster believes there is now growing interest in energy recovery.

"Energy prices have been high for a while now and are expected to be high; crude oil and electricity and diesel fuel have also been high for several years and people expect it to stay the same or go up in the future," he said. "People are concerned about the liability of energy sources, which certainly increases interest in the science around energy recovery."

Jesse Klinkhamer, CEO of Klean Industries, believes North America is behind the trend of waste-to-energy because for years resources were "plentiful" and society had freely adopted a throwaway mentality.

"When things are cheap, it's business as usual. It's not until someone gets a pinch and it starts to hurt, when they realize there might be a better way," he said. "If there is a more efficient way to do things and you can profit and still be green, why not do it?"

Klean has been in commercial operation for more than 30 years and are able to process a wide variety of polymer waste such as plastics and tires and other post-industrial materials.

Klean's advanced thermal conversion technology, which has been developed and used commercially in Japan, captures the value in oil rich plastic packaging.

Dow & Klean collaboration

Wooster, aware of Klean's extensive background in energy recovery, visited the world's largest plastics-to-oil recycling plant in Japan with Klean, whose company owns the technology IP.

After visiting the 50 tons/ day plant, Wooster said that this was the only technology they have seen that has consistently operated for more than a decade on a commercial scale. The facility Dow visited processed mixed plastics, including PET and PVC at up to 20% of the in-feed supply, in addition to polyethylene, polypropylene and polystyrene. At the same time, the facility also produced over 4MWe of green electricity.

The two companies have extended a three-year letter of intent, which allows them to combine proprietary technologies, knowledge and resources to provide "best in class" solutions for end-of-life mixed plastics. They plan to collaborate on the possibility of developing recovery facilities across North America.

Klinkhamer said it's no easy endeavor to bring energy recovery facilities to the North America. Ultimately, it comes down to access to feedstock for these plants.

Still, he said Klean's phone is ringing on a daily basis with potential customers who are interested in this alternative energy. Inquiries run the gamut from large companies to smaller "mom and pop" operations.

"There are existing technologies in the marketplace today that allows you to be a better corporate citizen, this is one of them," he said.

In the end, Dow is working to make sure plastic packaging just doesn't end up in the garbage and landfill.

"If we got rid of plastic packaging there would be terrible ramifications both for the economy and the safety of food supply," Wooster said. "We want to help people understand the science and how good plastic packaging is to protect food supply, and we also believe that part of being a leader in the industry is to help find another use for packaging when it's done, instead of just throwing it away."

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