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Invisible emitter no more: Penn State researchers create a new product that shatters glass emissions

diagonal glass windows
Image Credit: Christian Ladewig // Unsplash

When it comes to material emissions, from concrete to steel, glass is often invisible.

Its footprint may not be as big as its construction counterparts, but it isn’t exactly transparent, with glass manufacturing responsible for 86 million tons of carbon dioxide emissions annually. That’s the amount of energy from over 10 million homes annually, which is enough to power every household in Pennsylvania for a year two times over.

Glass manufacturing is dirty, with the bulk of emissions coming from the extremely high temperatures needed to melt glass. That’s why researchers at Pennsylvania State University have launched a new product that Windexes glass’s emissions, wiping them off at the source.

According to the researchers LionGlass, as they’ve dubbed it, breaks the emissions of conventional glass nearly in half.

The thing about glass, as an editorial in Nature put it, is that it’s an essential mineral that can “be recycled infinitely without losing any of its properties.” However, there are two caveats to this seemingly simple solution.

For one, the world, especially the United States lacks the necessary regulation to scale glass recycling to the point of making the industry carbon-neutral. While Europe is way ahead in the glass recycling game, with all new glass in the European Union made with 52% recycled material, and 70% of glass recycled, the U.S. is behind, landfilling over 7 million tons of glass in 2018, while recycling just under a third of glass containers according to data from the Environmental Protection Agency.

Secondly, even when all glass is recycled, some new glass will still have to be made, the editorial notes, explaining the type of glass used for its most common application, windows, cannot contain impurities. Known as flat glass, this glass needs to be so pure and crystal clear that melted-down jam jars, wine glasses, and old Pyrex containers can’t yield a window pane.

So, though a circular economy of perpetually recycled materials is the end goal, reducing the emissions of the manufacturing process of glass is not only necessary in the interim of proper recycling regulation but is necessary when windows, and thus, the need for flat glass, isn’t going anywhere.

That’s why researchers at Penn State have created a new type of flat glass, scientifically known as soda lime silicate glass. Flat glass isn’t just for windows, as soda lime silicate glass is also common in glass tableware and containers.

“Our goal is to make glass manufacturing sustainable for the long term,” John Mauro, a professor of material sciences and engineering at the university and lead researcher on the project said in a statement.

“LionGlass eliminates the use of carbon-containing batch materials and significantly lowers the melting temperature of glass.”

A sample of LionGlass, a new type of glass engineered by researchers at Penn State that requires significantly less energy to produce and is much more damage resistant than standard soda lime silicate glass
A sample of LionGlass, a new type of glass engineered by researchers at Penn State that requires significantly less energy to produce and is much more damage resistant than standard soda lime silicate glass. Credit: Adrienne Berard / Penn State. Creative Commons

Made with three primary materials — quartz sand, soda ash, and limestone — soda ash and limestone release notable amounts of planet-warming CO2 when they are melted.

LionGlass begins by slashing emissions in materials, however, according to the researchers, the bulk of emissions come from the energy required to heat furnaces to the high temperatures needed for melting glass, which is a staggering 1500 to 1700°C (2700–3100°F). According to Mauro, with LionGlass, ​​the melting temperatures are lowered by about 300 to 400 degrees Celsius (about 570-750°F), which cuts the glass emissions by another third.

Named in honor of the school’s lion mascot, the research team also reports that LionGlass is much stronger than traditional glass while being ten times more crack resistant. Aside from being useful for quality products across sectors from healthcare to construction to automotive, damage resistance also means longer-used, and thus, more sustainable products.

Mauro and his team don’t plan to stop at one product. While they’re still researching and evaluating the potential of LionGlass, they have filed a patent application for the entire family of different types of glass. Flat glass may be just the start.

“Humans learned how to manufacture glass more than 5,000 years ago and since then it has been critical to bringing modern civilization to where it is today,” Mauro said in a statement.

“Now, we are at a point in time when we need it to help shape the future, as we face global challenges such as environmental issues, renewable energy, energy efficiency, health care, and urban development. Glass can play a vital role in solving these issues, and we are ready to contribute.”

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