The effects of beneficiation on ash formation in a pilot-scale combustor

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:171595

Strobel, T M; Hurley, J P; Chow, O K; Levasseur, A A

Ash formed during coal combustion in a utility boiler can deposit and impede heat transfer, thus decreasing the efficiency of the system. Coal cleaning is used to decrease the amount of mineral matter in coal, which may minimize deposition problems. In order to study the effects of coal cleaning on coal combustion, the U.S. Department of Energy Pittsburgh Energy Technology Center has contracted with Combustion Engineering Inc. for a multi-year project to determine the combustion characteristics of beneficiated coal-based fuels. The specific objectives of the program are (1) to develop an engineering database that will provide detailed information on the properties of approximately fifteen beneficiated coal-based fuels (BCFs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) to apply this technical database to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. This paper focuses on the effect of beneficiation on fly ash particle size, chemical composition, and deposition of Upper Freeport, Pittsburgh No. 8, and Illinois No. 5 beneficiated products produced by the selective microagglomerate process (1). These products were tested in ABB Power Plant Laboratories Fireside Performance Test Facility (FPTF) at 3.0 x 10{sub 6} to 4.0 x 10{sub 6} Btu/hr under standard and staged low-NO{sub x} firing conditions. Bulk ash particulate and deposit compositions were determined by x-ray fluorescence (XRF) and crystalline phases by x-ray diffraction (XRD). Computer-controlled scanning electron microscopy (CCSEM) was used to quantity the composition and size distributions of coal minerals and fly ash particles with sectioned diameters between 1 and 100 {mu}m (2). The CCSEM provides detailed information on size and composition of individual particles that can be useful for interpreting ash behavior during combustion.

• Research Organization: Coal and Slurry Technology Association, Washington, DC (United States); USDOE Pittsburgh Energy Technology Center, PA (United States)
• OSTI ID: 171595
• Report Number(s): CONF-950313--; ON: TI96120227
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ASHES
BOILERS
CHEMICAL COMPOSITION
CLEANING
COAL
COAL PREPARATION
COMBUSTION
COMBUSTORS
PARTICLE SIZE
PILOT PLANTS
SYNTHESIS