by AF 0902j3 — September 5, 2008—Stanford Professor Brent Constantz said he has invented a green cement that could eliminate the huge amounts of carbon dioxide spewed into the atmosphere by the manufacturers of the everyday cement used in concrete.
His vision of eliminating a large source of the world’s greenhouse gas has gained traction with both investors and environmentalists. The Calera Corp. has a pilot factory in California that is producing the cement in small batches, according to a story in the San Francisco Chronicle.
And Carl Pope, executive director of the Sierra Club, says it could be “a game changer” if Constantz can do it quickly, on a big scale and at a decent price.
For every ton of ordinary cement, known as Portland cement, a ton of air-polluting carbon dioxide is released during production. Worldwide, 2.5 billion tons of cement are manufactured each year, creating about 5 percent of the Earth’s carbon dioxide emissions.
Constantz claims his new approach not only generates zero carbon dioxide, but also reduces the amount greenhouse gases power plants emit by sequestering it inside the cement.
Constantz takes exhaust gas and bubbles it through seawater. The chemical process creates the key ingredient for his green cement and allows him to sequester a half ton of carbon dioxide from the smokestacks in every ton of cement he makes. For more information, see the San Francisco Chronicle Web site.
