IN a blow to clean coal development, the Kemper County power plant in the US has been forced to abandon lignite gasification and burn gas instead.
The plan had been to gasify 4.7m t/y of lignite from an adjoining mine, burn the resulting syngas to produce power and use the captured carbon dioxide for onshore enhanced oil recovery. Work began on the plant in 2010 with startup originally scheduled for 2014. Earlier this month, with costs ballooning US$4bn over budget to US$7.5bn, the local authority in Mississippi called for the plant to quit “unproven technology”, burn natural gas instead, and for shareholders not consumers to absorb the financial losses.
Southern Company, the plant owner, has now suspended operations of the gasification portion of the plant, noting that it is “the appropriate step to manage costs given the economics of the project”.
Described by Southern Company as state-of-the-art technology, the facility’s two gasifiers have successfully produced power from syngas but operators have struggled to keep the design running uninterrupted.
The technology chosen for the plant was an integrated gasification combined cycle design called TRIG, developed by Southern Company, KBR and the US Department of Energy. The design has been promoted on the basis that it can cost-effectively and efficiently process low-grade coal containing lots of moisture. KBR says the benefits over other designs include that it uses less water so is suitable for dry regions and less oxygen so saves energy.
The US has only nine large-scale CCS sites operating at commercial scale, according to data from the Global CCS Institute. The only one currently capturing carbon dioxide from coal is the Petra Nova post-combustion facility in Texas that started up in September last year.
