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Fluidized Bed Technology - An R&D Success Story

In the early 1990s, POWER magazine called the development of fluidized bed coal combustors "the commercial success story of the last decade in the power generation business." The success, perhaps the most significant advance in coal-fired boiler technology in a half century, was achieved largely through the technology program of the U.S. Department of Energy's Office of Fossil Energy (and its predecessors).

The Interior Department's Office of Coal Research, one of the forerunners of the Energy Department, began studying the fluidized bed combustion concept in the early 1960s.

The original goal was to develop a compact "package" coal boiler that could be pre-assembled at the factory and shipped to a plant site (a lower cost alternative to the costly onsite assembly of conventional boilers).

In the mid-1960s, the Government recognized that a fluidized bed boiler not only represented a potentially lower cost, more efficient way to burn coal, but also a much cleaner technology. The same turbulent, or "fluidizing," mixing of the coal to improve combustion also provided a way to inject sulfur-absorbing limestone to clean the coal while it burned.

A 500-kilowatt fluidized bed test plant built in Alexandria, Virginia, in 1965 probably could be called the "grandfather" of U.S. fluidized bed coal combustors. It provided much of the design data for a 30-megawatt prototype unit at the Monongahela Power Company's Rivesville, West Virginia, plant built in the mid-1970s.

The Georgetown University fluidized bed unit still operates today. The first commercially successful fluidized bed was an industrial-size atmospheric unit (equivalent to a 10-megawatt combustor) built with federal funds on the campus of Georgetown University in Washington, D.C., in 1979. The Georgetown unit currently still operates. Today, every major U.S. boiler manufacturer offers an atmospheric pressure fluidized bed system in its product line.

 

The Nucla fluidized bed power plant in Colorado was operated in DOE's Clean Coal Technology Program.The technology progressed into larger scale utility applications due, in large part, to Federal partnership programs with industry. The Colorado-Ute Electric Association project in Nucla, Colo., (now operated by Tri-State Generation and Transmission Association, Inc., of Denver) was one of the early demonstrations in the Clean Coal Technology Program. From this project came significant design improvements in utility-scale atmospheric fluidized bed technology, and as a result, commercial confidence in this advanced, low-polluting combustion system picked up considerably.

In 1996, the municipal power company serving Jacksonville, Fla., committed to the community to reduce pollutants from its Northside Station by at least 10 percent when it replaced two of the plant's obsolete and inefficient oil- and gas-fired units. JEA (the utility was originally called the Jacksonville Electric Authority) chose atmospheric fluidized bed technology to meet its pledge and at the same time generate significantly more power from the refurbished facility.

The Energy Department contributed more than $74 million to the JEA project as one of the original projects under its Clean Coal Technology Program. The federal funding went to install one of the two combustors. JEA converted a second boiler to the new technology entirely with its own funding.

Jacksonville, FL, now generates a large part of its electric power using fluidized bed combustion.On October 14, 2002, the utility declared the new technology to be fully operational. The two fluidized bed systems at the Northside Station each generate 300 megawatts of power, enough to light over 250,000 average households. At the time they went into operation, they were the largest fluidized bed combustors ever installed in a power plant. The editors of POWER magazine, one of the most widely read publications in the electric utility industry, presented the magazine's 2002 Powerplant Award to the Northside facility.

Following start-up of the JEA CFB combustor, four demonstration tests were completed as part of the Department of Energy's Clean Coal Technology Demonstration Program.  The first test burn began January 5, 2004, and was completed 11 days later.  The initial test used 100 percent Pittsburgh No. 8 coal.  The second test burn ran from January 16-31, 2004, and used 50 percent Pittsburgh No. 8 coal and 50 percent petroleum coke.  The third demonstration phase test burn using 100 percent Illinois No. 6 coal was completed June 1-10, 2004.  The fourth and final test ran from August 10 until August 12, 2004, and used 20 percent Pittsburgh No. 8 coal and 80 percent petroleum coke. 

All tests were conducted at 100 percent, 80 percent, 60 percent, and 40 percent of full load.  Emissions were monitored at each load level and were well below permitted values.

In July 2005, JEA completed its final report on the successful demonstration phase for its CFB combustion plant.

Today, more than $6 billion in domestic sales and nearly $3 billion in overseas sales have resulted from the U.S. public and private investment in circulating fluidized bed technology research, development and demonstration.