Last updated on January 20, 2024.
Glass is 100% recyclable!
“Ninety-three percent of consumers still expect to be able to recycle glass.” -Glass Recycling Coalition1
In my article about glass recycling in Chattanooga, I learned and shared with you why glass is no longer accepted in curbside recycling. I shared that glass recycled through curbside for about 4 years was not recycled, it was landfilled instead. Last, I solved the mystery of whether or not the glass at the five recycling centers was actually recycled – and it is, by Strategic Materials in Atlanta.
I learned that glass recycling is complex and difficult to understand. So I am explaining how the system works in general in two parts. I hope it helps you understand!
“Recycling glass saves one-quarter to one-third the energy over virgin materials production.” -Daniel Imhoff, Paper or Plastic2
Recycling happens when it is profitable
First, you have to realize that waste management and recycling are businesses. BIG businesses. The solid waste industry in the U.S. was worth approximately $91 billion in 2022, an increase from $82 billion in 2021.3
So it comes down to money. Economics. Seems like all things do! I thought for years that it happened because it was the right thing to do for the environment.
Nope. Recycling happens because recycling makes money.
How glass is collected
It starts with you and me, the consumer. We clean and sort the glass, and recycle it through the local Solid Waste Division of the city or municipality where we reside.
In a single-stream recycling system, meaning a system in which all recyclables go into one blue bin, the materials are sent to a Materials Recovery Facility (MRF) for sorting. A MRF’s primary function is to sort materials, decide what to do with those materials, and then sell and transfer them. Here’s a short YouTube video to give you a visual understanding:
How does this arrangement come to be? A city, local government, or municipality asks for and receives bids for waste management. A MRF is awarded the contract and often a hauling company as well; they are usually funded through property taxes. WestRock is the MRF for Chattanooga as well as many other municipalities in the Southeast U.S.
Almost all municipalities pay a MRF to handle and sort their recycling. Then the MRF sorts the materials through a complex system (the process varies by company), and then they sell the materials for a profit. The primary markets for recyclable glass containers are the 75 glass container manufacturing plants in
the United States.
Sometimes, as in Chattanooga since January 2018, glass is not collected curbside. It must be taken to one of the five recycling centers, and that type of recycling is known as dual-stream recycling – materials are separated by the consumer into specific bins.
Glass is transported
Glass gets sent to a glass recycling company or glass manufacturer. The glass collected from dual-stream recycling goes straight to the glass recycling company. In our case, that is Strategic Materials, the largest glass recycling company in North America. In single-stream systems, the MRF separates the glass and sells it to a glass recycling company or manufacturer. (Single-stream recycling has a lot of issues, especially with glass. I’ll cover that in Part 2.)
There are forty-six glass manufacturers in the U.S., and often glass must be transported across state lines for recycling. Some large cities with lively nightlife do not collect glass, such as New Orleans and Nashville. “Municipalities choosing to go without glass point to the cost of hauling a material with low market value as the reason, but other industry folks argue that the glass market is not the problem. They consider the problem to be collection and assert that, if glass could be collected in ways that reduce its role as a contaminant, then we would see greater success with the material,” wrote Beth Porter in Reduce, Reuse, Reimagine.4
How glass is recycled
Glass is broken down and ground into cullet. Cullet and recycled glass melt at lower furnace temperatures than virgin (or new) glass ingredients, which saves energy. This also reduces carbon dioxide emissions. The Glass Recycling Coalition states: “Recycling glass has big environmental payoffs…it saves raw materials, lessens demand for energy, and cuts CO2 emissions.”5 The Glass Packaging Institute adds that glass recycling extends the life of plant equipment, such as furnaces, another cost savings.6
The technology for recycling glass just keeps getting better too. Watch this short NPR segment about it:
Unlike a plastic bottle, a glass bottle can become another glass bottle!
How Glass Recycling Should Work
Demonstrated in the following two infographics from the Glass Recycling Coalition is how the system should work when the recycling loop is not broken (meaning when the glass is not deposited into landfills):
It seems so simple!
Glass Recycling Proponents
The Glass Recycling Coalition(GRC), a non-profit, is a “mission-centric, organization fostering collaboration across the glass recycling value chain” who is “dedicated to breaking down barriers in order to keep glass in the recycling stream, meet and grow end-market demand and build awareness of the benefits of glass recycling.”7 They formed in 2016. Strategic Materials is a member. They also encourage MRF’s to become members. (WestRock is not a listed member, however.)
The Glass Packaging Institute (GPI) is a trade association representing the North American glass container industry. “GPI promotes glass as the optimal packaging choice, advances environmental and recycling policies, advocates industry standards, and educates packaging professionals.”8
The Container Recycling Institute (CRI) promotes the bottled beverage deposit system, called the Deposit Return System. In some states, this system charges the consumer a deposit fee of 5 or 10 cents. When the consumer returns that bottle for recycling, they get their money back. In some places, this includes glass, plastic, and aluminum bottles and cans. A Wall Street Journal article noted that “an average of around 63% of glass containers are recycled” in the 10 participating states.9 However, states that don’t have deposit programs only have a glass recycling rate of around 24%.
Tennessee does not participate in the deposit system. However, there is a proposal called the Tennessee Bottle Bill Project.
There are additional uses for glass
On top of recycling glass to make new glass containers, there are many other uses for glass in secondary markets. One of these includes road construction, using cullet either on the surface called “glassphalt” or as a road base aggregate.
Recycled glass is also used as filler aggregate in storm drains and French drain systems. Other markets and uses include the fiberglass industry; glass beads for reflective paints; abrasives; foam glass; and other building materials – even countertops!
There are lots of uses for glass.
There is a huge market for glass and so many uses for it. But if you search the internet for information about glass recycling, you’ll find many stories about different municipalities that no longer accept glass in their recycling system. The claim that there is limited or no market for recycled glass is not true. There is a huge market for it.
So why is this system breaking down? What problems are preventing recycling? That’s what I’ll be covering in Part 2. Thank you for reading!
Article, “Glass Recycling 101: Jars, Glass Cups and Wine Bottles,” Wine Cellar Innovations, accessed January 10, 2021.