Could pieces of plastic garbage become the resource we need to construct buildings? Scientist Veena Sahajawalla believes so. She has developed a way to recycle the trash nobody wants and turn it into steel.
Making Steel From Trash
Published August 15, 2018
Narrator: Can we make steel from trash?
Veena Sahajawalla: Landfills shouldn’t be seen as a burden, they should actually be seen as this amazing possibility. It’s a treasure.
Narrator: Veena Sahajawalla has developed a way to recycle the stuff nobody wants, trash, and turn it into steel.
Sahajawalla: The most basic steel is nothing but an alloy of iron and carbon. Well, guess what? We can find carbon in a plastic.
Narrator: The first step: take some plastic like this broken headlight…
Sahajawalla: So, look at what I’ve got here.
Narrator: …cut off a piece, and melt it down to a small pellet, chock full of carbon. Top it off with a lump of pure iron, place the combo back in the furnace and heat it up. Now, watch the alchemy unfold as the carbon in plastic bonds with iron.
Sahajawalla: What’s exciting here is that we’re actually seeing this high temperature reaction taking place right in front of our very eyes. We’ve got this liquid metal. We’re now looking at how this is interacting with this source of carbon, which, of course, is the plastic that came from waste out of a car, carbon from that plastic that is actually able to dissolve into liquid metal.
So, this is what’s come out of the furnace. We’ve dissolved the carbon from the plastic into liquid iron. And, of course, what we have here is steel.
Narrator: After a decade of research Veena’s “green steel” is slowly making its way out of the lab. Partnering with the manufacturer, OneSteel, they have already recycled over 2,000,000 tires. Today’s tires are made of synthetic rubber, produced from oil rich in carbon, the perfect ingredient for green steel. And when it comes to greenhouse gases, Veena’s steel requires less coal to cook, and that reduces its carbon footprint.
Sahajawalla: As the saying goes, you know, “one person’s trash is somebody else’s treasure.” Guess what? This could become a society’s treasure.
- Digital Producer
- Arlo Perez
- Editorial Review
- Julia Cort, Ari Daniel
- © WGBH Educational Foundation 2018