A new process stores carbon dioxide in precast concrete.

Greenhouse Gas, Sustainable Design Comments Off on A new process stores carbon dioxide in precast concrete.

A Canadian company says that it has developed a way for makers of precast concrete products to take all the carbon-dioxide emissions from their factories, as well as neighboring industrial facilities, and store them in the products that they produce by exposing those products to carbon-dioxide-rich flue gases during the curing process. Industry experts say that the technology is unproven but holds great potential if it works.

Concrete accounts for more than 5 percent of human-caused carbon-dioxide emissions annually, mostly because cement, the active ingredient in concrete, is made by baking limestone and clay powders under intense heat that is generally produced by the burning of fossil fuels. Making finished concrete products–by mixing cement with water, sand, and gravel–creates additional emissions because heat and steam are often used to accelerate the curing process.

But Robert Niven, founder of Halifax-based Carbon Sense Solutions, says that his company’s process would actually allow precast concrete to store carbon dioxide. The company takes advantage of a natural process; carbon dioxide is already reabsorbed in concrete products over hundreds of years from natural chemical reactions. Freshly mixed concrete is exposed to a stream of carbon-dioxide-rich flue gas, rapidly speeding up the reactions between the gas and the calcium-containing minerals in cement (which represents about 10 to 15 percent of the concrete’s volume). The technology also virtually eliminates the need for heat or steam, saving energy and emissions.

Work is expected to begin on a pilot plant in the province of Nova Scotia this summer, with preliminary results expected by the end of the year. If it works and is widely adopted, it has the potential to sequester or avoid 20 percent of all cement-industry carbon-dioxide emissions, says Niven. “If the technology is commercialized as planned, it will revolutionize concrete manufacturing and mitigate hundreds of megatons of carbon dioxide each year, while providing manufacturers with a cheaper, greener, and superior product.” He adds that 60 tons of carbon dioxide could be stored as solid limestone–or calcium carbonate–within every 1,000 tons of concrete produced. Further, he claims that the end product is more durable, more resistant to shrinking and cracking, and less permeable to water.

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The Cryosphere Today

Climate Change, Miscellaneous Comments Off on The Cryosphere Today

The Cryosphere Today is a website by University of Illinois devoted to the current state of our cryosphere. It gathers and re-represent the snow and ice data from the National Center for Environmental Prediction/NOAA. One can download the Sea Ice Animations from 1978-2006 and a custom apps for iPhone.

From Wikipedia:

“The cryosphere, derived from the Greek word kryo for “cold” or “too cold”, is the term which collectively describes the portions of the Earth’s surface where water is in solid form, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps and ice sheets, and frozen ground (which includes permafrost). The cryosphere is an integral part of the global climate system with important linkages and feedbacks generated through its influence on surface energy and moisture fluxes, clouds, precipitation, hydrology, and atmospheric and oceanic circulation. Through these feedback processes, the cryosphere plays a significant role in global climate and in climate model response to global change.”

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