August 15, 2007

Global Monitor (August 2007)

POWER digest

On-line monitoring of catalyst life. The U.S. Department of Energy (DOE) has announced the availability of a tool for in-situ testing of the activity level of catalysts used by selective catalytic reduction (SCR) systems to control plants' NO_x emissions. In a press release, the DOE claimed that the Knoxcheck Online system will help "plant operators to more cost-effectively comply with NO_x emission regulations, including the new Clean Air Interstate Rule."

Fossil Energy Research Corp. (www.ferco.com) developed the technology, which can monitor catalyst activity in an SCR system without having to shut it down to obtain samples from different layers—the traditional approach. The Knoxcheck system was tested at full scale on one unit of Southern Company's Gorgas plant, and the results were "similar to those obtained from traditional laboratory testing of catalyst activity," according to the DOE.

The DOE added that linking the results from Knoxcheck to data from EPRI's CatReact catalyst management software "helped Southern Company make proactive decisions about the operation of the SCR system and [evaluate the] overall NO_x compliance on the unit."

Keeping track of remaining catalyst life is crucial to the economic operation of SCR systems because catalysts are a big part of such systems' overall cost. The ability of a catalyst to convert NO_x to benign chemicals degrades over time because its surface is prone to pluggage by flyash. In SCR systems with multiple layers of catalyst, each layer can degrade at a different rate.

Alstom and E.ON plan carbon capture demo. Alstom and E.ON are launching a 5-MW demonstration of CO₂ capture at a power plant in southern Sweden. The demonstration, at the Karlshamm plant, will use Alstom's chilled-ammonia technology and is expected to begin in 2008.

According to an Alstom press release, research suggests that the technology can remove up to 90% of the carbon dioxide in flue gas. The company also says that using chilled ammonia for this purpose consumes far less energy than competitive technologies. Alstom says its studies predict a 10% energy loss, vs. a nearly 30% loss for other post-combustion CO₂ capture techniques.

The Alstom-E.ON deal is reminiscent of an agreement between Alstom and American Electric Power for a test at a West Virginia coal-fired power plant that also has a 2008 start date. If the AEP test works, the Ohio-based utility holding company will build a full-scale plant in Oklahoma in 2011. Wisconsin Electric Power is also working with Alstom on a carbon capture demonstration at the former's Pleasant Prairie plant.

Siemens completes offshore UK wind project. Siemens Power Generation says it has finished installing 25 3.6-MW wind turbines at the Burbo Offshore wind farm in Liverpool Bay. The project will be operated by SeaScape Energy Ltd., and its power will be sold into the UK grid. SeaScape is owned by the Danish utility DONG Energy A/S.

Siemens said it got the job done in one and one-half months, "well ahead of schedule." The project is expected to enter commercial service by the end of the year. For its onshore operations in support of the project, Siemens leased 45,000 square meters in North Wales. The German power giant says it assembled the 65-meter-high steel turbine towers upright and then tested all of the turbines' internal components and the plant's electrical systems before loading the towers onto a specially designed vessel that took them 7.5 miles offshore.

On each trip, the vessel carried the housings, hubs, and blades of three turbines. According to Siemens, the average time it took to erect one turbine, weighing almost 500 tons, was less than half a day.

The Burbo wind farm was the first offshore wind project for Siemens and the first in a series of projects that have ordered the company's 3.6-MW turbine. The next delivery, of smaller units, will be to the Swedish utility Vattenfall. It hopes to have 48 Siemens 2.3-MW turbines with a total capacity of 110 MW generating power offshore of Malmö by the end of this year.