Coal-Gasification Technology Introduced In China
Could this new technology lead the way to a new and cleaner coal? Here’s Technology Review’s article about this.
The industrial boomtown of Dongguan in southeast China’s Pearl River Delta could soon host one of the country’s most sophisticated power plants, one that uses an unconventional coal-gasification technology to make the dirtiest coal behave like clean-burning natural gas. Its developers, Atlanta-based utility Southern Company and Houston-based engineering firmKBR, announced the licensing deal with Dongguan Power and Chemical Company this month.
Dongguan Power plans to implement the gasification scheme at an existing 120-megawatt natural-gas-fired power plant, turning it into an integrated gasification combined cycle (IGCC) plant that uses cheap, moisture-laden lignite coal. The retrofit should be operating in 2011. That will provide its developers with a demonstration to determine whether technology will work in larger IGCC plants and whether it is a process suitable to integrate carbon capture and storage technology, according to John Thompson, director of the Coal Transition Program for the Clean Air Task Force, a nonprofit environmental consulting firm based in Boston. “They want to show that this works,” says Thompson.
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.
Clean Technology, Environment, Infrastructure, Innovation, coal
