Syngas: A Transformative Technology for Waste Circularity

To reap the upstream environmental and economic benefits of lightweight, single-use plastic packaging while at the same time ensuring it never becomes waste, Lakhan said he likes to tell people, “We need to start thinking outside of the Blue Box.” He added, “It’s important to recognize that we have more tools in our toolbox than just mechanical recycling. Both companies and legislators continue to look toward mechanical recycling as the solution to our packaging waste problem. But isn’t insanity trying the same thing over and over again, expecting a different result? We’ve done it [mechanical recycling]. We’ve tried for the better part of 30 years, and we’ve done an amazing job. But it’s simply not working anymore.

“When we look at proposed [EPR] legislation put forward in states such as Oregon, Maine, and New York, it’s forcing a mechanical recycling solution, and I can’t imagine why we would achieve a different and preferable environmental outcome, given the experiences we’ve had in Canada.”

While mechanical recycling has its place in a sustainable waste management system, it’s not the be-all and end-all, Lakhan concluded. “As a result, we need to embrace alternative forms of recovery, such as syngas, and increase awareness surrounding it and why it should be used and when it can be used.”

Syngas offers a transformative path to circularity

Dr. Bruce Welt, Professor of Packaging Engineering at the University of Florida and a member of the CWC Academic CommitteeAccording to Dr. Bruce Welt, a Professor of Packaging Engineering at the University of Florida and a member of the CWC Academic Committee, unlike traditional reduce, reuse, recycle strategies, which offer incremental advantages, syngas has the potential to fundamentally transform waste handling. “Syngas is an advanced downstream end-of-life process that takes materials and makes them available for new manufacturing,” he explained. “In this way, we have to have to think differently about waste handling and think of it more in terms of manufacturing.”

With the current industry mindset, upstream changes in packaging are often made more for marketing points, rather than to create real impact, Welt noted. For example, in the case of Keurig Dr Pepper, a switch to polypropylene from polystyrene for its coffee capsules sounds like a sustainable win. But, in order to recycle the package, consumers must peel the lid from the capsule and empty the grounds, a process that requires diligence from the consumer and has resulted in the development of more materials in the form of tools that can be used to dismantle the capsules. “And, at the end of the day, if you speak with the material recovery facilities, regardless of whether you dissect a K-cup or not, they will say, ‘It’s too small. It goes through the screens and ends up in a landfill anyway,’” Welt said. “What’s the benefit there?”

Another example he shared of erroneous attempts to create more sustainable packaging would be companies that switch to biodegradable materials. “If biodegradable materials end up in landfills, which most of the material will, they will degrade anaerobically and generate methane, which is a very potent greenhouse gas. Moving to a biodegradable package and putting it in a landfill is ultimately going to be worse than using traditional plastics. These things are individual, they’re short-lived, and they’re not really improving the situation.”

Instead, Welt suggested that the greatest gains can be realized by looking downstream—at an advanced recycling infrastructure that is more robust and where the benefits can be quantified because “we know how much material we’re taking in.”

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There are several advanced recycling options that can be used for packaging waste. Among them are depolymerization, which is a process used to chemically recycle PET. While effective, it can only be used with PET and only produces virgin PET, “so it doesn’t solve the complexity that we’re dealing with in the marketplace right now,” explained Welt. Another technology, solvent recovery, uses specific solvents to dissolve different substrates. The need for different solutions for different materials is one drawback, another is the issue of the solvents themselves. “Drawing a box around these processes and where the solvents come from becomes kind of shady,” noted Welt.

Another process outlined by Welt is pyrolysis/cracking, which results in a char product, pyrolysis oil, and synthesis gas. If the material being pyrolyzed is exclusively biomass, the char is usable; if mixed waste is used, then the char becomes waste. In addition, the pyrolysis oil needs to be refined, meaning the yield, in terms of conversion of waste into new recycled content, is relatively low. “What we end up having to do is mix that pyrolysis oil from waste in with fossil material, so the contribution in terms of recycled content gets diluted—we’re talking single digit-type numbers,” he explained.

Another process that is well established is gasification, which uses carbon-based materials to produce synthesis gas for use by major chemical companies, such as Eastman Chemical. “They’ve been gasifying coal for the purpose of making synthesis gas, which we could use to make primary feedstock chemicals that go into plastics and all kinds of other things,” said Welt.

But the mission of CWC is to take gasification one step further, to create an advanced recycling process that offers the greatest feedstock robustness and product versatility in the form of Regenerative Gasification. Explains the consortium website, “Regenerative Gasification is a process that achieves higher temperatures than gasification, in excess of 3,400°F. At such temperatures, organic chemical bonds are broken, and inorganic materials are melted down. Carbon-rich organics are primarily converted into synthesis gas (‘syngas’), comprised mostly of carbon monoxide and hydrogen. Metals and inorganic oxides (i.e., glass/metals) are melted down and recovered as ingots and glassy materials. All products become feedstocks for subsequent value-added commercial applications.”

It adds that syngas is a highly versatile chemical feedstock. “There is nothing that can be made from fossil fuels that can’t be made from syngas. Ideally, syngas will be converted into feedstock chemicals such as methanol, ethanol, dimethyl ether, acetic acid, etc. to be used for subsequent synthesis by the chemical industry.”

Feedstock for Regenerative Gasification can include any type of mixed-waste packaging, including multilayer plastic materials, shrink labels, adhesives, packaging contaminated with food waste, and other hard-to-recycle materials. “It doesn’t matter if there’s a metal fitment, if there’s foil or metallization, the process can handle all of these things, and the primary output would be synthesis gas,” said Welt. “This type of a robust process would simplify the collection of our trash, because we would not only be able to think outside of the Blue Box, but we could also get rid of the Blue Box. We could truly do single-source collection. And then, what we would do is change the idea of sorting—we’d be selecting, not sorting. We need to really think of it that way. When we have a robust process that can capture everything, it doesn’t mean we have to, there are healthy recycling markets for many of the materials in there [the Blue Box]. We could be much more selective about what we’re pulling out of the waste stream, which would enhance the value of the mechanical recycling we’re doing now.”

The remaining materials would then be recycled via Regenerative Gasification to produce syngas. Explained Welt, “The first simple molecule we can make from syngas is methanol. Methanol is essentially a fungible primary feedstock chemical that chemical companies use to make virtually everything. There’s not a chemical company in the world that would say no to a truckload of methanol that was produced from waste and counts as recycled content.”

This Eco-Methanol™, explained Welt, “is the vehicle that will carry recycled content back into the circular economy.”

A shared vision is essential for progress

Currently gasification is being done all over the world. In Asia, coal is used as feedstock; in Europe and North America, it’s natural gas. Among the industries competing for a piece of the syngas pie are the airline industry for jet fuel, the auto industry for fuel cells, and the agricultural industry for fertilizer.

Advised Welt, “The point here is that the packaging industry needs to recognize that there’s competition for the waste, and so we have to have a shared vision that if infrastructure is going to go in, the syngas gets converted into methanol, and that is our best hope for gaining that recycled content.”

Read related article, "Solutions for a Circular Plastics Economy"

According to the consortium’s website, its mission of transforming the recycling infrastructure through the advancement of economically sustainable waste-to-syngas technologies will be aided by:

·      Supporting the education of municipality leadership through land grant university outreach programs

·      Advocating for waste-to-syngas public policies

·      Advocating for public policies that drive demand for post-consumer resin content

·      Collaborating with stakeholders to further advanced recycling projects

·      Providing educational opportunities on the benefits of Regenerative Gasification for all supply chain stakeholders

·      Promoting R&D for Regenerative Gasification and other technologies by providing funding to the University of Florida’s Advanced Recycling Initiative

Although Ted Yoho, a former U.S. Congressman who served on the Agriculture and Foreign Affairs Industry and a member of CWC’s Public Affairs Committee, opened the webinar, his introductory comments serve as a fitting conclusion as well. “The opportunity to join this movement, to create a future for the packaging and print industry, backed by science, that is truly circular, is here,” he said. “The technology transforming waste into usable and affordable products is here. To accomplish this will take us all participating in this solution—let your voices be heard and counted.”