22. April 2014
Earth Day is about action. About measuring and minimizing strain on the environment. About forging more sustainable ways of living and working. And more than a billion people around the world do exactly that every year at the end of April. With Earth Day upon us, I talked with my son about the environmental impact of glass. How sustainable is glass as a material, he wondered. How sustainable are glass manufacturing processes?
These are fair questions. Manufacturing glass, like steel and other materials, is energy-intensive. And some glass manufacturing traditionally used harmful materials during processing. But much has changed and continues to change. We’re focused on continually improving our processes to create glass with a lighter energy footprint that’s better for the planet, and yet still maintains quality and reliability.
Here are a few ways glass maintains a sustainable edge:
1. Glass outlasts most materials. Any discussion of glass and the environment is bound to turn to recycling at some point. And for good reason: Glass can be recycled endlessly and recycling can have a profound impact on sustainability — all glass bottle recycling in 2012 had the same impact as removing 210,000 cars from the road.
Every glass manufacturer relies on recycling to an extent. For example, we use waste glass to start a new tank as we begin our manufacturing process. But glass’ environmental impact is further reduced if the glass remains in use for decades, as our glass does as part of cooktops, fireplace windows, telescopes, airbag igniters, and more.
Glass is incredibly durable, resistant to oxygen, water, and other elements that seep into and break down materials like steel or plastic. That’s why archaeological digs uncover glass and ceramic artifacts that are sometimes thousands of years old. So while recycling glass bottles is a necessity due to their short shelf life, tapping into glass’s longevity can make it more sustainable in the long run.
2. Energy efficiency drives glass manufacturing. To turn raw materials into finished glass products requires a great deal of heat and power — depending on the glass type and composition, melting temperature can be as high as 2,912 degrees Fahrenheit (1600 degrees Celsius). For this reason, we’re always seeking opportunities to improve efficiency. From optimizing tanks to improving melting processes to capturing waste energy, manufacturers can develop more cost-effective and sustainable ways to produce glass.
At SCHOTT we track how much energy it costs to produce each kilogram of glass and continuously work to improve our target. We’ve done this by replacing large tanks with smaller, purpose-designed tanks; reducing waste material; and monitoring heat exchange to capture energy and convert it back into electricity. Through these efforts, we’ve significantly cut energy usage in our manufacturing, and we’ve reduced the consumption of fresh water for manufacturing by more than 80 percent since 1989.
3. Glass is cleaning up its act. Glass manufacturers can better protect the environment and human health by drawing on sustainable materials and eliminating harmful elements from their processes. SCHOTT began removing the dust from glass melting tanks as early as 1978. Today, melting tank waste gasses are more than 99.5 percent dust-free. In addition, nitrous oxide emission levels have been reduced by 75 percent since 1990.
SCHOTT CERAN glass-ceramic, for example, is primarily composed of natural raw materials, like quartz sand, that are virtually inexhaustible, and it curbs the use of harmful materials that have traditionally been used in glass manufacturing.
Arsenic and antimony have long been used to refine glass and eliminate bubbles during the manufacturing process. But by developing new methods of producing glass, SCHOTT has eliminated the use of these toxic heavy metals not only in CERAN but in PYRAN Platinum fire-rated glass-ceramic as well. In addition, more than 80 percent of our optical glasses are now free from arsenic and lead. And PURAVIS high-purity glass optical fibers are free of arsenic, antimony, and lead.
Eliminating the use of arsenic and antimony for CERAN alone keeps 180 tons of these environmental bad actors out of production lines. By eliminating harmful materials through new manufacturing processes and relying primarily on sustainable materials to produce our glass, we’re able to develop components and materials that better respect the planet.
Earth Day challenges all of us to be better — more efficient, more sustainable, more future-focused. When it comes to glass, as I explained to my son, manufacturers focused on continuously improving processes to extend product life, maximize energy use, and eliminate harmful materials offer plenty to celebrate this Earth Day.