Eco-Cement Removes CO2 from the Air!
by on 03.18.05
Cement gets a bad rep for the colossal amount of energy it takes to manufacture it. Eco-Cement earns its first point for using lower temperatures in production. With these lower energy requirements, it’s easier to use wind, solar, or other renewable energy sources. OK, good, but is that all? Nope. According to developer John Harrison, Eco-Cement turns “virtually any solid waste” into concrete—a great way to reduce landfill junk. The concrete (which can be pressed into blocks or poured) can be recycled, too. And it gets even better: Eco-Cement actually absorbs carbon dioxide from the air for up to a year, made possible by the addition of magnesium oxide into the material. How cool is that? Because the cement must stay semi-porous to facilitate CO2 absorption, it’s not the highest-strength concrete available, but low-strength concrete is enough for two-thirds of projects. There are even tricks in place for obtaining the magnesium from energy-production waste. Reduced energy to produce, reduced waste in landfills, and reduced CO2 in the air: sounds like a full score to us. Thanks to Jess Macfarlane for the tip! Via ABC Online ::TecEco [by KK]
I've read this ecocrete a couple of times and can't figure out the science behind it. I don't think it quite works like the hype says. I mean, you have to push CO2 through it to trap the CO2. This is how carbon sequestering works. But the CO2 just stays in the concrete. I think this is alot more hype than substance, but that is just my gut instinct. Concrete is not a CO2 generator, but making the portland cement for the concrete is. A more intresting solution that I have seen is sequestering CO2 from the point source of the cement kiln. This would be relatively easy, but you still have to in effect landfill the CO2. I think currently the prefered method is mineralization, which I think is what ECOcrete is trying to do.
Magnesium hydroxide is probably hygroscopic (pulling moisture out of air). If it is included in the concrete, the hydroxyl ion will be mobile and very slowly reacting with carbonic acid, created by hygroscopic properties of substrate, to form immobile magnesium carbonate. At some point the hydroxide is exhausted completely, eliminating the function of C02 removal. Knowing the half life of the function is critical to evaluating cost effectiveness.
dude. you guys are like scientists.
Where can I buy eco-cement in or around San Antonio, Texas?