Tuesday, September 29, 2009

China Pioneers Commercial IGCC Coal to Gas

While the Obama administration and the Pelosi Congress are doing everything possible to prevent viable new baseload energy production in the US, China is developing technology originally invented in the US and the west. With IGCC, even the dirtiest forms of coal can be used cleanly. Given China's record of coal pollution, we can only hope they hurry to install IGCC in all of their coal power plants.
Southern and KBR's gasification design can use dirty coal because, compared to other gasification reactors, it uses a relatively slow, low-temperature process. Conventional gasifiers, such as General Electric's and Shell's, rely on temperatures around 1,500 ºC to turn finely ground coal into a combustible mixture of carbon monoxide and hydrogen known as syngas. Unfortunately, such temperatures melt ash and other mineral contaminants in the coal, forming a glassy slag that eventually eats through the ceramic tiles that protect the reactors' steel walls. Even reactors using high-quality coal have to be taken out of service for installation of new tiles at least every three years. They are thus ill-adapted for lower-quality coals that would produce several times more slag.

Dongguan's gasifier will sidestep those issues by operating at just 925 ºC to 980 ºC, below the contaminant melting temperature, explains Randall Rush, Southern Company's general manager for gasification systems. Coal nevertheless gasifies completely at these lower temperatures because it spends twice as long in Southern and KBR's process.

The technology is an adaptation of the fluidized catalytic cracking employed in refineries since the 1940s, which processes petroleum by "transporting" it around a loop along with solid catalyst particles. In the gasification reactor, the incoming feed of fresh coal is transported with a looping flow of solid coal contaminants, primarily ash. The hot mass drives off most of the coal's energy content as syngas. The solids left over simply join the flow. __TechnologyReview
Al Fin engineers have long recommended the use of IGCC (integrated gasification combined cycle) plus CHP (combined heat and power) for using coal. The fact that even the lowest quality coal can be consumed cleanly using this highly efficient technology, greatly expands the useful coal reserves worldwide.

Extra!!!: Here is a fascinating look into the much ballyhooed wind energy movement in China. More wind means more coal. As simple as that. Denmark's experience should have been enough to prove to die-hard airheads that utility scale wind power is much more expensive than virtually any other form of energy, due to the need for constant backup power. Utility scale storage would help, but would not totally solve the problem. Think baseload.

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