What say we clear the air … specifically of carbon dioxide, that nasty greenhouse gas pollutant; and when we do, we make a useful product as well … concrete.

An enterprising company, Blue Planet, is unleashing some really cool technology involving biomineralization, the process by which coral reefs and shellfish use carbon dioxide to make their mineral shells. It’s the same process that an oyster employs to make a pearl. One could opine it’s a “gem” of a process.

Quick refresher:
Conventional cement–Portland cement–is made primarily of calcium oxide; but at Blue Planet, their aim is to make a different kind of cement made primarily of calcium carbonate. Cement is the binder that makes concrete–which also contains aggregate, sand and water. About 5-7% of the planet’s greenhouse gas emissions comes from the making of concrete.

The Blue Planet process can feed off a nearby source of carbon dioxide like a natural gas-fired power plant and convert the carbon dioxide into calcium carbonate [limestone], at the rate of a ton of material every two hours. A pilot plant capable of producing 10,000 tons of material a year is being planned. Blue Planet hopes to clean the air and give conventionally produced concrete a run for its money. Famed actor, Leonardo DiCaprio serves on one of the advisory boards of Blue Planet.

Cement is used in many applications around the globe-man’s ubiquitous building material

At the University of California, a team is hard at work to also produce concrete using another interesting angle. They start with that pesky carbon dioxide and make a slurry of calcium hydroxide as a feedstock to 3D printers to form beams and other shapes for construction. Since conventional cement making is a great source of carbon dioxide, the U of C effort is aiming at using that carbon dioxide source to make more environmentally clean cement.

The University work is in its early stages, but shows promise. They can ultimately produce usable building shapes in about two hours, compared to waiting 30 days for conventional concrete to fully cure.

J.R. DeShazo, left, and Gaurav Sant show off a sample of the new building material they have created to replace concrete.

It’s worth noting that Mr. Edison revolutionized the traditional concrete-making process at the same time he was creating concrete homes, way back in 1910-1915. He increased the efficiency of cement making. Now, the use of carbon dioxide in the air and in combustion gases is being used to make concrete. I think I see a smile forming on Tom’s face. He was no friend of air pollution as he felt electric vehicles were a much cleaner form of transportation than gasoline vehicles; and he was also a big proponent of solar energy. Were he alive today, Edison would embrace this kind of air cleaning research!

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