FUEL 83 |
| Carbon dioxide sequestration has become important due to fossil fuel consumption and the warming effect of carbon dioxide in the environment. Without drastic changes in the generation, consumption, and source of energy, sequestration is likely to be needed to abate global warming. While there is no single solution to this problem, mineral carbonation is a method that can form stable carbonates and sequester carbon dioxide for geologic time frames. The most energetically and cost effective method to form mineral carbonates is to dissolve a starting mineral in acid use this solution to prepare a scrubbing agent for flue gas. The most abundant starting material for such an operation is serpentine. The layered silica structure in serpentine causes the dissolution to proceed incongruently which leaves a high-silica-content, amorphous diffusion layer behind. Researchers have demonstrated that incorporation of an attrition-type grinding during the digestion can greatly speed the extraction process. However, practical operating conditions and an adequate rate model had not been developed. Early findings have shown that a model which accounts for surface charge, surface reaction, ash layer diffusion, particle size distribution, material balance, and solution equilibrium can adequately describe the extraction profile under batch operating conditions. With this model, it was revealed that the attrition-type grinding is not sufficient to keep the serpentine surfaces clear of the high-silica-content diffusion layer, but rather has the effect of lowering the layer's effective diffusivity.ity. |
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Carbon Capture and Storage
1:25 PM-4:55 PM, Tuesday, August 19, 2008 Doubletree -- Symphony Blrm, Oral
Sci-Mix
Division of Fuel Chemistry |