Saturday, August 23, 2008

Carbon Sequestration ...

... new technique for storing carbon dioxide identified.
In his small-scale reactor, Van Essendelft grinds a serpentine rock mixed with water and acid. The combination of grinding and chemical action (mainly the acid) breaks down serpentine into magnesium and silica, which is essentially sand. He then adds ammonia and pumps CO2 in. The ammonia neutralizes the acid, allowing the CO2 to dissolve and react with magnesium, forming magnesium carbonate.

Magnesium carbonate is similar to chalk and has several applications. For example, Van Essendelft says, it could be used instead of limestone to produce cement.
This would be an interesting means of carbon sequestration for anaerobic digestion (AD) on-farm. You already have a surplus of ammonia from the animal waste, and about 35% of the bio-gas from AD is carbon dioxide.

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