Blue Planet Produces Concrete by the Uptake of CO2
Each year there's a demand of 50 billion tons of concrete, worldwide. This human-made material is the most abundant and chances are, it is surrounding you right now. Our modern world needs concrete to build never-ending highways, bridges, buildings and dams. Yet, producing concrete releases colossal amounts of carbon dioxide (CO2) into our atmosphere. This happens due to concrete's essential ingredient which acts as its glue - cement.
Cement is what makes concrete a strong material. To do so, it requires the superheating of calcium carbonate or in other words, limestone. One single ton of cement produces roughly one ton of CO2. This makes cement responsible for 7% of global CO2 emissions by anthropogenic activities. Since cement's production doesn't show any signs of decreasing, its carbon footprint is expected to get worse.
That is not a great helper when we're all fighting climate change.
Luckily, some people are working hard to provide us with solutions to thrive, as humans living on earth.
Silicon Valley, entrepreneur and marine geologist Brent Constantz launched his company Blue Planet in 2012. He aimed to capture carbon in an economic and sustainable way. To accomplish this, Constantz created concrete by pulling CO2 out of the atmosphere (or directly from industrial exhaust pipes). The result is to turn CO2 in synthetic limestone, which is used to make concrete.
The Foundation for Climate Restoration estimates that a trillion tons of CO2 must be removed from our atmosphere. Blue Planet's idea is growing to reach that point. Not only by slowing down the pace of climate change but to send it back to its normal and healthy CO2 levels.
How does it work?
Blue Planet's method starts by collecting CO2 and dissolving it in a solution. This will turn CO2 into CO3 - calcium carbonate - an important ingredient in limestone. Afterwards, Blue Planet turns the resulting stone into pebbles that will serve as aggregate.
”We’re turning the CO2 into synthetic limestone, by using a process very similar to what happens in oceans when corals grow. Each ton of CO2-sequestered limestone traps 440 kilograms of carbon dioxide, preventing it from ever reaching the atmosphere again. Even if you tear down the building, the carbon’s still in the limestone” - says Constantz.
This idea makes the entire concrete production carbon negative. Additionally, the production itself requires less energy than traditional ways.
It also reduces limestone mining.
”About 70 percent of all rock used in concrete is limestone. There is about 50 billion tons of rock that is mined every year and transported for use in concrete, asphalt and road base, and it’s growing at about 8 percent a year. Our approach would save enormous transportation costs and carbon footprint" - says Constantz.
This solution alone could restore pre-industrial levels in only 40 years, by removing a trillion tons of CO2 from our atmosphere. It could also help to boost new infrastructures and industry aiming to clean the planet. Whole cities and homes can be built with CO2-based concrete and give a big rest to our atmosphere.
Blue Planet already applied its creation to a new terminal at the San Francisco International Airport. A study from Stanford University followed the whole process, concluding that Blue Planet's CO2-based concrete could decrease CO2 emissions by over 48%, when compared to traditional concrete.
Turning our carbon footprint into a carbon fingerprint
Concrete is the second most consumed product on the planet after water. Yet, when we hear about climate change we immediately bring airplanes, red meat and turning the lights off to the top of the list. Producing concrete has its consequences and they are quite significant.
Producing concrete from CO2 uptake may change the whole scenario. Likewise, other materials can follow the same method. Plastic and fuel, for instance, can be made from captured CO2.
There are so many ways we can go to make our planet safe from climate change.
Let's make that change, one road, building and city at a time.
Keywords: Blue Planet, concrete, CO2,