Carbon Looping: Updated report Feb 11, 2013 The following is a portion of an updated report on carbon looping. If anything is going to propel coal forward it will be a discovery such as this...even though it will take time to put into use.
'In contrast, the Ohio State researchers mix pulverized coal with beads of iron oxide, a compound akin to rusty iron. They do this in a reactor heated to about 1,650°F, and the coal inside reacts to produce carbon dioxide and water in the form of steam.
With the proper equipment, the steam cools into liquid water, leaving pure carbon dioxide, which can be sequestered or used for enhanced oil recovery.
After the reaction is complete, the hot iron beads are transferred to a second reactor, where they undergo combustion. This combustion is different from, say, burning a charcoal briquette, in that it produces no flame. But the hot iron beads nevertheless react with air and produce heat—“the same amount of heat as if you would have burned coal,” Fan said. That heat boils water to produce steam, which drives a turbine that produces electricity.
At that point, the iron beads are now partially rusted again—that is, they have oxygen attached—and they’re returned to the first reactor to react with more coal. It’s this recycling that gives “looping” techniques their name.
Because carbon dioxide separation occurs essentially as part of the combustion process, “the ‘capture’ energy requirements are almost negligible,” and far less than amine scrubbing, Fan said. That could dramatically lower the cost, he added.
Coal-direct chemical looping has another advantage over burning coal, Fan said. Iron burns at 2,000°F, far lower than the 4,500°F needed to burn coal, and at this lower temperature nitrogen in the air does not form nitrogen oxides.
That means that compared with flue gas from burning coal, levels of nitrogen oxides are much lower in the flue gas, which means “there’s much less to scrub,” Fan said.'
for full detail: https://www.midwestenergynews.com/2013/02/11/ohio-states-carbon-capture-breakthrough-still-has-long-road-to-adoption/
Sharpei