Glass Recycling’s Fragile Market

Oct 6, 2017, 21:03 PM
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November/December 2016

Glass has gotten a bad rap as a high-cost, low-value material to recycle, even though residents want to see it turned into new products. Can municipalities, MRFs, processors, and manufacturers make it work?

By Megan Quinn

Glass has long had a bad reputation within the scrap recycling industry. It breaks easily and contaminates paper in a mixed recycling stream. It’s hard on separation equipment, has a low value, and is expensive to transport because it’s so heavy. And with the rise in popularity of single-stream recycling, glass that comes out of materials recovery facilities these days is much more contaminated than it was 10 years ago, experts say. MRFs wonder if they can justify the expense of producing a cleaner stream when the demand picture isn’t always clear. When the glass value is not high enough to cover transportation costs, the fragile material often ends up in the last place anyone wants: the landfill. Because of these logistical and economic hassles, cities such as Houston have decided to stop collecting glass from curbside residential recycling.

Despite its bad rap, glass definitely has its fans. Residents are enthusiastic about recycling their glass and want to see it recycled. Household recycling has helped the supply of recycled glass grow in the past 20 years, which is good news for secondary processors and glass producers, who say they want to buy even more recycled glass to turn into high-value products such as new beer bottles, food jars, and fiberglass insulation.

So what are the keys to successful glass recycling? Improving quality, controlling costs, and finding consistent demand, experts say. MRFs and processors that can work together to produce squeaky-clean cullet likely will see better profits, and if the heavy material can be transported shorter distances, so much the better, says Lynn Bragg, president of the Glass Packaging Institute (Arlington, Va.).

More recyclers are starting to talk about what it will take to successfully recycle glass, Bragg says. A new coalition of glass industry stakeholders is brainstorming innovative ways to tackle recycling problems, and a separate ReMA group is drafting MRF glass specifications in an effort to ease misunderstandings and better communicate about the quality of glass that comes from MRFs.

Both new initiatives might help get more glass through the recycling stream and turned back into new products, Bragg says. “We know Americans want to recycle glass,” she says. “We know we need improvements” to make that happen.

Supply Trends

The recovered glass supply has increased slowly in the past 20 years, most notably because of the greater convenience of single-stream recycling, according to GPI. As recycling participation has increased over the years, so has the proportion of glass in the recycling stream. In 1995, the glass recycling rate was about 32 percent, but it was 36 percent by 2013, according to the Container Recycling Institute (Washington, D.C.). That year, recyclers recovered 3.13 million tons of glass, according to the U.S. Environmental Protection Agency.

The proportion of glass collected has continued to go up, even as companies such as Coca- Cola favor plastic or plant-based packaging over glass. Glass is now a larger portion of the recycling stream by weight because that stream now has many more lightweight items, such as plastics. Glass packaging is 25 percent of the average single-stream residential mix by weight, compared with about 15 or 20 percent in 2006. Even though glass remains heavier than plastic, glass bottles also have gotten lighter over the years due to design improvements. The average glass bottle is 40 percent lighter than it was 30 years ago, says Bryan Vickers, a consultant for GPI.

Single stream may have helped increase recycling volume, but it did not increase the quality, Bragg says. Only 60 percent of the glass collected through single-stream systems gets recycled into containers and fiberglass, which are considered the highest-value uses because these products net the highest prices and are in demand year-round. The remaining 40 percent goes into lower-value alternative recycling uses such as road striping or abrasives—which bring in less profit and are typically in demand only during certain seasons—or it ends up as alternative daily cover in a landfill because high contamination levels make it unusable in the more lucrative markets, she says.

Strategic Materials (Houston), the largest of North America’s glass processors, purchases about 2.5 million tons of recovered glass a year. Executive Vice President Curt Bucey says single- and dual-stream collections provide the bulk of the glass Strategic Materials buys, but what you get is “highly variable and highly contaminated.”

Bucey prefers buying cleaner glass from deposit systems in the 10 bottle-bill states of California, Connecticut, Hawaii, Iowa, Maine, Massachusetts, Michigan, New York, Oregon, and Vermont. This kind of glass is already sorted by color and is much cleaner than single- or dual-stream glass, he says. CRI says 98 percent of deposit-state glass is recycled into containers and fiberglass. This glass is in high demand, making it the most expensive to buy, Bucey says.

There’s another way to collect glass, too: through source separation systems. Residents can opt into a curbside recycling program specifically for glass, or they can take their glass to special drop-off sites in their town. Source separation methods, which are more commonly found in cities where MRFs don’t accept glass in single- or dual-stream systems, produce a cleaner glass stream, but volumes are lower because it takes more effort for users to drop it off or put the glass in a special bin, Bucey says. It has worked well in some places, such as Kansas City, where local processor Ripple Glass has quadrupled its collection and processing capabilities since it launched its collections at bars, restaurants, and other locations seven years ago. In Salt Lake City, residents can sign up to have their glass collected curbside by Momentum Recycling, a processor that recently expanded its operation into Denver. Portland, Ore., also has glass-only collection bins as part of its regular curbside recycling pickup program.

Quality Concerns

Is there sufficient demand for the growing supply? It depends on who you ask. Some secondary processors and glass producers say there is huge demand for cullet, and they would happily buy more, but they struggle to find the supply. Yet some collectors, such as MRFs and municipalities, say they have an abundant supply of glass but can find few markets for it. Who is right?

“Both are accurate, but both are also inaccurate,” says Tom Outerbridge, general manager of Sims Municipal Recycling (New York). What glass processors and producers mean is the existing supply does not fit their needs, either because available cullet is too dirty or it doesn’t meet manufacturing specifications. For example, Strategic Materials “[takes] all types of glass. Curbside single stream, dual stream, factory rejects, even automotive windows,” Bucey says. He wants to buy even more glass, but he runs into one type of problem over and over: Glass loads often are full of trash. A load might be as little as 50 percent glass, he says. He adjusts prices based on the quality of the glass he receives, paying less when glass needs more cleaning. But the reason for the low price might not get communicated to the municipal government, he says, which is problematic. “My observation is that cities are not knowledgeable about glass recycling costs,” he says. “Say a MRF delivers 10,000 tons to me on an annual basis, and they report that to the city. In reality, they might have delivered 5,000 tons of glass and 5,000 tons of residue. Cities don’t drill down and understand that, and they are happy to hear the MRF diverted 10,000 tons. … When I change my price because I’m getting more residue, the MRFs go back to the city and say the price isn’t good and the market isn’t good.” That leads the city to stop taking glass.

Houston is one example, Bucey says. The city signed a new contract with Waste Management (Houston) in March that no longer included glass recycling among its services, even though residents want to recycle their glass. The company says low commodity prices make it harder to profit from glass recycling, and they had to cut the service to save money, he says. Strategic Materials, which had bought Houston’s glass from Waste Management, will instead position 10 drop-off containers around town. The city doesn’t pay for the containers, but Strategic Materials also does not have to pay for the recycled glass. Bucey hopes Houston and Waste Management will add glass back into the recycling contract in the future.

The MRF Perspective

Though processors like Bucey want glass to be cleaner when it leaves the MRF, creating a cleaner glass stream is harder than you’d think, Outerbridge says. MRFs can install or upgrade glass cleaning machinery, but doing so is expensive, and most see that move as having a low return on investment, especially when glass values are already so low compared with other commodities. Most MRFs that have opted for such machinery have strong ties to a buyer nearby, such as a processor or bottlemaking plant, he says. But if they need to ship glass long distances, or if they don’t have a steady demand for glass, it doesn’t seem worth it to them to improve their system, he says. So when a collector says it can’t find a buyer for its glass, it means it can’t find the right buyer, Outerbridge says—one that will pay enough to justify the costs. “There certainly is a home for glass. … Instead of saying ‘there is no market,’ they should say ‘the existing market doesn’t justify the money and resources I need to spend’” to make the glass meet the buyer’s needs, he says.

Outerbridge thinks more MRFs might start investing in cleaning glass if the price for the machinery goes down. “If we can bring down the cost of sorting glass to specifications of the marketplace, that could help. Will it be enough to solve the problem? Probably not, but [recyclers] are always trying to find marginal improvements,” he says. Until that happens, or until glass values improve, “glass is not a priority for MRFs.”

Bragg agrees that helping MRFs with the investment in better technology might create cleaner glass. GPI recently gave grants to two single-stream MRFs—American Recycling of Western North Carolina (Asheville) and Sonoco Recycling (Raleigh)—for equipment and technology for improving glass quality. The North Carolina Department of Environmental Quality matched the grants. It is the first time GPI has ever given grants, Bragg says, and it’s not clear whether the program will continue or have a significant impact on the industry. No-interest loans are another possible solution, she says.

MRFs that successfully produce clean glass have tried different methods for keeping their glass competitive and attractive to buyers. Sims Municipal Recycling, which serves New York and New Jersey, has a glass recycling setup that is very different from typical MRFs, Outerbridge says. He describes it as “halfway between a MRF and a [glass] processor.” Most MRFs segregate glass from the rest of the stream and clean it as much as necessary to be able to sell it to a processor, but Sims goes an extra step because of the requirements of its buyers. It screens the glass by size, sends it through a glass breaker, and then through an optical sorter that picks out the clear glass. The rest of the glass is cleaned and crushed into an aggregate.

Outerbridge says this setup works because Sims has plenty of glass to sort—between 8,000 and 10,000 tons a month, he says—making the return on the investment in additional technology worthwhile. “We do a lot more than most MRFs because our MRFs produce a lot more glass. We do less processing than the [glass] processors, though, so we’re in the middle,” he says.

Today, Sims sells its glass only to bottlemakers, but Outerbridge is researching the possibility of also selling to insulation manufacturers in the future. One challenge is researching and meeting the needs and desires of the insulation market, he says. One company refuses to take amber-colored glass, but it does want green. Another company doesn’t care about the color and will take a mix of it all, he says.

Another MRF that found a creative market solution for its glass is Rumpke Consolidated Cos. (Cincinnati), the second-largest privately owned waste and recycling collector in the United States. In 2004, Rumpke decided it couldn’t keep recycling glass without more market stability, so it built a plant next to its MRF facility in Dayton, Ohio, to make fiberglass-insulation-grade cullet. Steve Sargent, Rumpke’s director of recycling, says it undertook a $3 million optical-sortation upgrade in 2012 and now sells about 65 percent of its cullet for insulation and 35 percent for bottles.

What Buyers Want

Before investing in cleaning equipment, MRFs might want to assess their location and extent of demand, says John Lair, president of Momentum Recycling. Successful processors “need a strong, reliable anchor buyer” to turn that cullet into a new bottle or a component for fiberglass, he says.

GPI says the container and fiberglass industries collectively purchase 3 million tons of recycled glass each year. About 2.4 million tons is used to make bottles and jars. The average glass bottle or jar has about 33 percent recycled glass, which is a 6- to 7-percent increase since 2009, when the institute started collecting data on recycled content. This trend is a signal that manufacturing companies want to purchase more recycled glass, but Bragg says the glass packaging industry still needs to step up its game. “We’re not using enough recycled glass … considering the fact that 28 billion glass containers were made” in 2015 alone.

One obstacle to more use of recycled glass is price. Buyers, whether they are purchasing from MRFs or other processors, want to keep their costs low, and clean cullet often is more expensive than virgin materials, Lair says. Momentum’s glass cullet competes for market share with other glassmaking components found in abundance in or close to the Utah desert: sand, lime, borax, dolomite, and fly ash, he says.

Cullet may be more expensive in direct comparison with its virgin raw materials, but it is still an attractive option for companies that want to reduce their carbon footprint and help offset costs elsewhere, says a spokesperson for bottlemaker Owens-Illinois (Perrysburg, Ohio). As part of the glassmaker’s global sustainability benchmarks, it uses at least 38 percent cullet in its bottle production to offset energy costs. Making bottles with recycled cullet requires less energy because the cullet melts at a lower temperature. That also means fewer emissions, he says. For every 10-percent increase in recycled glass use at Owens-Illinois bottle plants, the company sees a 3-percent reduction in energy use.

The beer industry is an increasing player in the recycling game, says Lair. Buyers for Momentum’s new Colorado location include Owens-Illinois, which makes bottles for big clients like Budweiser and MillerCoors. While the beer industry has used recycled glass “for a long time, their appetite for it has increased,” he says. “I think this is in part a response to their customers wanting a ‘greener’ option, but mostly [it’s] a factor of cost.”

Lair says no one knows beer’s role in recycling quite like Ripple Glass in Kansas City, Mo., which processes about 40,000 tons of glass a year it collects from seven states. One of the company’s founders is also the founder of Boulevard Brewing, which uses some of Ripple’s glass in its beer bottles. (The majority of glass Ripple processes goes to Owens Corning in Toledo, Ohio, which uses it for fiberglass insulation.) Ripple Glass plans to expand even more, according to the Kansas City Business Journal.

Lair says Momentum and Ripple’s success comes from finding the “sweet spot” in the glass recycling chain: a continuous source of relatively clean glass, typically from residents of larger cities; nearby processors that can collect and process high volumes of glass without spending a lot on transportation costs; and glass producers who are also nearby to turn sparkling cullet into lots and lots of bottles or other products.

Lair uses Momentum’s soon-to-open Denver facility as an example. Momentum started in Salt Lake City because it was an ideal environment with source separation. And, if you looked on a map, there were few other processors and glass producers around, “meaning we were cornering the market,” he says. Expanding into Denver made sense because the area has a similarly ideal setup: a large waste and recycling stream from a Denver-area population of between 5 million and 6 million people; a strong collection program, this time through several different MRFs instead of a source separation system like Salt Lake City; and the two bottle manufacturers close by. “It’s important that we have both of [the manufacturers as consumers]. These facilities have planned downtime where they could be down for a month, or down for six weeks, for furnace maintenance. It can be disruptive to business if you don’t have another buyer.”

Bucey says Denver, Salt Lake City, and Kansas City are success stories, and he has high hopes for Georgia, where “the markets are among the strongest in the nation. There’s a high concentration of glass container plants [and] fiberglass plants, most of which want more cullet,” he says. Yet many MRFs in the state have stopped accepting glass.

Bragg says the strong markets in Georgia are what spurred the newly formed Glass Recycling Coalition to meet there in September to discuss recycling challenges. The group aims to identify best practices and generate new ideas on how to increase glass recycling. The summit revealed some exciting possibilities that may help solve kinks in the supply chain there, she says. Representatives from Decatur, Ga., surveyed residents and found 95 percent of them want to recycle glass, even though the local hauler has stopped accepting it. Those residents said in the survey they would pay a small fee to keep their service. In DeKalb County, “an outcry from residents” angry their glass recycling was taken away convinced the county to offer drop-off bins, she reports. She’s not surprised at residents’ strong responses when glass recycling is no longer available. In Georgia and across the country, “when I hear [another city] has stopped taking it, people start calling [us]. The phones ring off the hook.”

Participants in the summit identified a few next steps, such as creating workshops for MRF operators to explore financing strategies for getting new or upgraded glass separating equipment, Bragg says. The GRC also wants to start citizen groups to establish community-level recycling programs.

The Georgia summit was just a jumping-off point for GRC to move forward with other new ideas, she says. GRC members include GPI, ISRI, bottlemakers, beer industry representatives such as New Belgium Brewing, recyclers, and other associations, she says. The group is working on a website,, to offer information on glass recycling, including best practices, recycling studies, and other resources. It also will plan more events to keep all stakeholders at the table to communicate and solve glass recycling problems as a team, she says. “It’s exciting when you have a cross-section of the whole glass recycling chain. You need everyone working together,” she says.

Megan Quinn is reporter/writer for Scrap.


Can Specifications Bring Clarity to the Glass Market?

Misunderstandings between MRFs and secondary processors might be less frequent if there was a common specification for MRF glass that can be bought and sold as feedstock, some say. A task force of ReMA members is developing MRF glass specifications with the Glass Packaging Institute and other stakeholders, and it hopes to present a draft to the ReMA board at the 2017 convention in April in New Orleans.

The specs are “meant for better communication,” says Tom Outerbridge, general manager of Sims Municipal Recycling (New York) and chair of the specification group. “It doesn’t change the merit or the value of [the glass] … and it doesn’t guarantee that there’s a market for it. It simply allows people to have a common understanding of what they’re getting.”

What the specifications might do, says Curt Bucey, executive vice president of Strategic Materials (Houston) and a member of the MRF glass specifications group, is help set more realistic and clear expectations among municipalities, MRFs, and buyers. He hopes that cities include specifications in their future contracts. John Lair, president of Momentum Recycling (Salt Lake City), says the idea of having set specifications could help communication, but there’s no guarantee that companies will find them useful. “I like the idea of having an even playing field where everyone is held to the same standards,” he says. “The challenge is going to be … [glass products are] different in each city, and the specifications for bottle manufacturing cullet are much different than the specs for fiberglass,” he says. “Each processor wants something different from the MRF operators.”

For more information about the specification process or to get involved, contact Jonathan Levy, ISRI’s director of member services, at

Glass has gotten a bad rap as a high-cost, low-value material to recycle, even though residents want to see it turned into new products. Can municipalities, MRFs, processors, and manufacturers make it work?
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