Combustion-based hybrid systems use coal as fuel, and employ combustion technologies in combination with a gas turbine in a number combined cycle configurations. One of these hybrid systems is known by its acronym: CHIPPS, for: ‘combustion-based high-performance power system.’ CHIPPS is a coal-fueled technology that is suited for repowering units that have boilers in good condition, as it continues the use of the existing furnace and steam tubes. This paper describes a conceptual evaluation to establish the feasibility of using CHIPPS technology to repower an existing coal-fired steam plant. The H.F. Lee power plant, owned by CP&L Progress Energy, is located on the Neuse River, just outside Goldsboro, North Carolina. CHIPPS would repower Unit 2, a 1950’s era non-reheat steam unit, one of the three units at this site. If CHIPPS repowering proved feasible for Unit 2, it would likely be a good choice for a wide range of other similar units throughout the U.S. CHIPPS retains the use of the existing Unit 2 furnace and steam turbine/generator, but adds a combustion turbine to increase energy efficiency in a way that makes this coal-fired plant nearly as efficient as a combined cycle power plant that would otherwise use more expensive natural gas. The CHIPPs technology concept used employs a Foster Wheeler circulating fluidized bed partial gasifier that would supply syngas to a General Electric 6B combustion turbine. Only a portion of the coal is gasified to syngas. The remaining coal energy is transferred as char to the lower of three boiler burner rows of the existing Unit 2 furnace that would be fitted with special burners for the char. The upper two rows are not changed and continue to burn coal from the existing mills. With CHIPPS: • Output is expected to increase from 78,520 kW to 139,750 kW, • 7 percent less fuel would be needed per kWh generated, • Environmental improvement would become exemplary, however, • Cost is high, about $214,606,000; Unit 2 is too small for attractive economics, and a non-reheat unit leads to only modest efficiency improvement. Future CHIPPS repowering might be better suited for a larger reheat steam plant instead of at H.F. Lee Unit 2. This paper summarizes the CHIPPS repowering power plant concept and describes: • An overview of the CHIPPS process; • A description of the existing H.F. Lee Unit 2; • An estimate of the performance improvements expected with Unit 2 repowered with CHIPPS; • An estimate of the environmental performance expectation from the unit with CHIPPS; and, • An estimate of the expected costs to upgrade the unit. Significant conclusions and suggestions for where this class of hybrid combustion technologies might best be applied.

Semi-dense phase pneumatic delivery and injection of calcium and sodium sorbents, and microfine powdered coal, at various sidewall elevations of an online operating coal-fired power plant, was investigated for the express purpose of developing an in-furnace, economic multipollutant reduction methodology for NO x , SO 2 & Hg. The 154 MWe tangentially-fired furnace that was selected for a full-scale demonstration, was recently retrofitted for NO x reduction with a high velocity rotating-opposed over-fire air system. The ROFA system, a Mobotec USA technology, has a proven track record of breaking up laminar flow along furnace walls, thereby enhancing the mix of all constituents of combustion. The knowledge gained from injecting sorbents and micronized coal into well mixed combustion gasses with significant improvement in particulate retention time, should serve well the goals of an in-furnace multi-pollutant reduction technology; that of reducing back-end cleanup costs on a wide variety of pollutants, on a cost per ton basis, by first accomplishing significant in-furnace reductions of all pollutants.