Glass Recycling Simplified: A Step-by-Step Process

Glass recycling is a fascinating process that turns old bottles and jars into new products.

Did you know that the first glass was made way back in 3500 BC? For a long time, glass was the go-to material until plastic took over. But today, as we strive for a greener planet, glass is making a big comeback because of its recyclability.

Here’s how it works: Glass is collected, sorted by color and type, and then processed. This involves crushing the glass into small pieces, which are then melted and remolded into new items. This not only conserves energy but also reduces the need for raw materials, cuts emissions, and even extends the lifespan of recycling machinery.

Surprisingly, out of the 12 million metric tons of glass waste Americans produce each year, only about one-third is recycled. What about the rest? Unfortunately, it often ends up in landfills, not decomposing. 

By understanding and participating in glass recycling, we can make a significant difference. So next time you toss a glass bottle into the recycling bin, remember its journey and impact!

Is Glass Recyclable?

Glass recycling is a true win for the environment—100% recyclable, it never loses quality no matter how many times it's recycled. To kick off the recycling process effectively, glass should be separated from other materials. This prevents contamination and ensures that glass recycling is as efficient as possible.

I remember the first time I visited a recycling plant; the mountains of glass bottles destined for a new life made a lasting impression on me.

The process of making new glass requires sand, soda ash, limestone, and various additives for color and special treatments. Extracting and processing these natural resources consumes a significant amount of energy and depletes our natural reserves. 

Consider this: recycling just one ton of glass not only saves 1.2 tons of raw materials but also reduces CO2 emissions by about 580kg across the supply chain. That's a substantial cut in air pollution by 20% and a 50% reduction in water pollution!

The impact of throwing a single glass bottle into the recycling bin rather than the trash can is more significant than you might think.

By recycling our glass, we also reduce the emissions of process CO2, particularly from limestone, a carbonate raw material. This simple act of recycling has a ripple effect—lowering the need for fossil fuels and cutting down on greenhouse gases.

Are All Types of Glass Recyclable?

While all types of glass are recyclable, for the sake of practicality, we don't recycle all of them.

It's crucial to understand not all glass is the same. Glass items like bottles and containers can be recycled together but shouldn't be mixed with other types such as windows, ovenware, or crystal. These are made differently and, if recycled together, could lead to production issues and flawed products.

Interestingly, for consumers, recycling glass is simpler compared to plastics, which often confuse with their array of recycling symbols.

Glass typically uses three main symbols:

• GL-70: clear glass
• GL-71: green glass
• GL-72: brown glass

All of these are 100% recyclable, and it’s easy to distinguish between them.

Certain glass types can't go into your recycling bin. Ceramic glass, found in some cookware, melts at different temperatures and can't be mixed with bottle glass.

Tempered glass, used in vehicles and some furniture, is treated for strength, altering its melting properties. Similarly, Pyrex and other high-temperature-resistant glasses differ too much in composition.

Mirrors and windows often have coatings that are problematic in recycling processes. Lastly, light bulbs, especially fluorescent ones, contain metals and chemicals like mercury, which require special handling.

Lead crystal, another non-recyclable type, is prized for its clarity but contains lead, making it unsuitable for general glass recycling due to its different melting point and characteristics.

Here's a list of  glass types that typically can't be recycled:

1. Ceramic glass
2. Tempered glass
3. Pyrex and borosilicate glass
4. Mirror glass
5. Window glass
6. Light bulbs
7. Lead crystal

Step-by-Step Glass Recycling Process

Many glass products can be recycled endlessly in the same stream. However, the US infrastructure is currently set in such a way that contamination levels are between 50% to 60%.

Here’s how is glass recycled properly:

1. Collection and Transportation

Glass starts its recycling journey from various points—home recycling bins, office spaces, and community drop-offs. These could be on your curb or at local recycling centers designed for community use. Businesses often have their own ways of collecting glass too.

Once gathered, the glass is transported to facilities that specialize in recycling it.

2. Sorting

At the recycling center, the first task is to sort the glass.

High-tech optical sorters scan for and remove anything that's not glass, like metals and plastics. They also pick out unsuitable glass types like Pyrex and mirrors that can’t be recycled with bottle glass.

The glass is also sorted by color. Colors are made from different additives, and mixing them can mess up the recycling process.

3. Crushing

Next, the sorted glass is broken down. Machines with heavy hammers crush the glass into small pieces. A little water is sprayed to keep dust from spreading.

4. Rotary Screening

These glass fragments then go through a screening process. Large rotary screens sort the pieces by size. At this stage, a strong fan blows away paper labels still stuck to the glass.

Pieces that are too big and other non-glass materials are removed and dealt with separately. Some might be recycled differently, while others might have to go to the landfill.

5. Thermal Agitation Drying

Now, the glass pieces are dried in a bed drier, which shakes them around as hot air flows through. This step helps remove any remaining sugar, bacteria, or glue. A vacuum system sucks up any leftover contaminants.

6. Primary Screening and Pulverization

If some pieces are still too large, they go through a mesh screen. Anything that doesn't pass through goes into a pulverizer. This machine continues to break down the glass until it’s small enough to pass through the mesh.

7. Secondary Screening

With the glass now finely crushed, it undergoes one more screening. This time, it's to sort the glass by specific sizes, needed for different products.

8. The Cullet

Finally, what’s left is called cullet—small, pebble-like pieces of recycled glass ready to be turned into something new. This cullet can be as coarse as pebbles or as fine as sand.

This recycled glass isn’t just used to make new bottles and jars; it's also used in making fiberglass, ceramics, filtration systems, and even abrasives.

Each step in the glass recycling process is crucial for ensuring the material can keep being useful, without wasting our natural resources or filling up landfills. 

Challenges of Glass Recycling

Even though glass is a highly recyclable material, the US glass recycling data is not encouraging. 

In 2018, only 31 million tons of glass were recycled, and nearly 62% went to landfill. It’s estimated that 28 billion glass bottles are buried in landfills every year, where they take between 4,000 to 1 million years to decompose. 

Here’s how the US compares to European nations according to the Glass Packaging Institute, only 33% of all glass gets recycled in the US, compared to the 70% that’s recycled in Europe.

The main reason for the low numbers of glass recycling in the US is that recyclers are refusing glass recycling jobs.

There’s a lot of processing that has to be done to get the cullet in furnace-ready form. One of the main issues is that recycling in the US is done by single-stream collection. This means residents use recycling bins for different materials — aluminum, steel, plastic, different paper products, and more. 

Also, people throw many things that shouldn’t go in the bins. This contaminates the glass in the recyclable bin, and the recycling facilities have to sort through all of these, which requires time and resources. 

It can also happen that a facility can’t separate the glass from other materials or other glass colors, which results in contaminated products that they can’t find a market for.

Recycling facilities are refusing glass recycling jobs because of the difficulties with producing satisfactory cullet.

Factors That Make Glass Difficult to Recycle

Apart from the glass being the contaminant or being contaminated by other materials, several other factors make it difficult to recycle, such as:

Solutions to The Glass Recycling Challenges

Several things can boost glass recycling. 

One of those is legislation. Data from the Container Recycling Institute shows that states with container deposit legislation have a recycling rate of over 63%, while states that don’t have this legislation have a recycling rate of 24%.

Another solution is multi-stream recycling, which is common in Europe. Only 40% of glass from single-stream is recycled, compared to 90% from multi-stream systems. Multi-stream programs ask consumers to separate glass from other recyclables and deposit them in glass-only bins. 

This route would require consumer education and is more expensive than single-stream, but is cleaner, especially when it comes to the final recycling product. Another positive side of multistream is that it doesn't have to go through recovery facilities but straight to cullet processors. 

Environmental Impact of Glass

Yes, glass negatively impacts the environment. Most glass waste ends up in landfills in the US, where it takes 4,000 years upwards to decompose. 

75% of all glass ends up in landfills, which is the equivalent of 110,000 glass bottles going into landfills daily. 

Recycle Across America says that 28 billion glass bottles and jars are sent to landfills yearly. 

Why does this happen?

I’ve talked about single-stream waste and how the glass recycling process works. The problem is that only a small portion of the glass is able to be recycled this way. The majority of glass items can’t be optically sorted, usually due to breakage, and are sent to the landfill.

So, what happens to all this glass at the landfill?

It outlives generations of people while lying in a landfill, and it negatively impacts the environment. Glass in landfills can kill wildlife and impact air and water pollution.

Items made from glass can contain lead, cadmium, and mercury, which are hazardous for people and animals. For example, enameled drinking glasses can have 1000 times the limit level of lead and 100 times the limit level of cadmium. 

Broken glass in a landfill is also a hazard to wildlife, especially if it’s contaminated with toxic chemicals or other infectious substances. These can enter the bloodstream through a cut or a puncture.

Another negative impact of sending glass to landfills is wasted resources. A new study by the University of Southampton showed that glass might be even worse than plastic. Researchers compared beverage containers to determine their harm to the environment. 

This is because glass is mined from rare materials and uses a lot of fossil fuels to produce and ship. When glass ends up in landfills, a huge amount of resources is wasted.

How to Find Recyclers Who Accept Glass Recycling?

Did you ever wonder: How to find glass recycling near me? Luckily, it’s never been easier to find recyclers who accept glass. 

The best way of finding where you can recycle your glass is to use GreenCitizen’s Green Directory.

By using Green Directory, you’ll be able to find a place to recycle your glass in seconds. All you need to do is input the material you want to recycle, your location, and if you want services to be provided near your address. You can even choose how far the recycler should be located (5, 10, 25, 50, 100 miles).

Here’s how to use the Green Directory:

That’s all.

The Green Directory will list all the glass recyclers close to you in seconds.

Here’s an example:

Step 1: Search for: Clear glass containers

Step 2: Add Location/Zip Code: Valencia Street, SF

Step 3: Search Radius: 25 miles

Step 4: Enjoy Results!

After clicking “search,” scroll down, and you’ll see all the places that accept clear glass containers for recycling in a 25 miles radius.

Is It Better To Reuse Or Recycle Glass?

Recycling is always an excellent option, no matter if you need to recycle glass, an old printer, microwave, TV, or some other electronics. 

Glass recycling has several benefits:

However, glass recycling is becoming more difficult to perform, as recyclers are starting to refuse these jobs.

In this case, you should reuse glass. Reusing glass uses even fewer resources than glass recycling.

Here are some of my favorite ways to reuse glass. 

Liquid Soap Dispenser

Imagine having a Jack Daniels soap dispenser in your bathroom! 

It’s easier than you think. Simply buy a liquid pump, put it in the glass bottle, pour some soap, and you’re done.

This is also an original gift idea. 

Wine Bottle Bird Feeder

This is a great idea to reuse your old wine bottle and feed some birds. 

Start by choosing the bottle. It should be an interesting shape or have an eye-catching label or color to draw the birds.

When you construct a bird feeder, make sure it’s tall enough for the bottle to fit and leave out a few walls. Attach the bottle with wire rope to hold it in place, and secure it with washers and screws to the inner wall of the feeder.

Carve at L hook against the back of the feeder base, and place the bottle, so its lips rest on it. Finally, fill the bottle with a funnel, turn it upside down, and the seed will slowly come out.

Use Glass Jars as Storage

One final idea on how to dispose of glass is to reuse glass jars. Instead of throwing it out, fill the jar with something else. 

Glass jars can be used as storage for:

Need more inspiration?

Check out some more recycling and upcycling ideas.

FAQ

How Do You Recycle Glass? Final Thoughts

Both glass recycling and reusing are eco-friendly options. While there’s a lot of room for improvement in the US recycling system, we should take advantage of it as much as we can.

Whenever you wonder, “Where can I recycle glass,” use the Green Directory to find where you can recycle glass close to you.

Finally, if you’re out of options for glass recycling, you can always reuse your glass waste. Check Youtube, Pinterest, and the ideas I’ve mentioned above to get some inspiration.

Glass is one of the most eco-friendly materials out there, so let’s also dispose of it consciously.

If you have other ideas of how to dispose of glass responsibly, let me know in the comments below.