Effect of coal type, residence time, and combustion configuration on the submicron aerosol composition and size distribution from pulverized coal combustion

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6969098

Linak, W P

Pulverized samples of Utah bituminous, Beulah (North Dakota) low Na lignite, Deulah high Na lignite and Texas (San Miguel) lignite coals were burned at a rate of 2.5 kg/hr in a laboratory furnace under various (overall fuel lean) combustion conditions. Particle size distributions (PSD) and size segregated particle filter samples were taken at various positions within the convection section. Temperature and gas concentrations were measured throughout. The evolution of the submicron PSD within the convection section for the four coals was similar, although the location of the initial particle mode at the convection section inlet varied with coal type. While stage combustion of the Utah bituminous coal had a variable effect on the volume of submicron aerosol produced, staged combustion of two of the three lignites (Beulah low Na and Texas) caused a definite increase in the submicron aerosol volume. Chemical analysis of the size segregated particle samples show the trace elements, As, Pb, Zn, and the major elements, Na and K to be enriched in the submicron aerosol. Auger depth profiles show these small particles to be comprised of a core enriched in Fe, Si, Ca and Mg and surface layers enriched in Na and K. These results point to a mechanism of homogeneous nucleation of low vapor pressure species followed by successive layering of progressively more volatile species. Volatile species are enriched in the submicron aerosol due to the large surface areas provided. Modeling efforts show that while coagulation may be the dominant mechanism to describe the aerosol evolving within the convection section, it cannot be used solely to predict the PSD. Another mechanism, presumably surface area dependent growth (condensation) must be included.

• Research Organization: Arizona Univ., Tucson (USA)
• OSTI ID: 6969098
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600 -- Coal
Lignite
& Peat-- Properties & Composition
014000* -- Coal
Lignite
& Peat-- Combustion
AEROSOL WASTES
AEROSOLS
ALKALI METALS
ALKALINE EARTH METALS
ARSENIC
ASH CONTENT
ASHES
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CALCIUM
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COLLOIDS
COMBUSTION
COMBUSTION KINETICS
DISPERSIONS
DISTRIBUTION
ELEMENTS
ENERGY SOURCES
ENRICHMENT
FLY ASH
FOSSIL FUELS
FUELS
IRON
KINETICS
LEAD
LIGNITE
MAGNESIUM
MATERIALS
MATHEMATICAL MODELS
METALS
MOISTURE
OXIDATION
PARTICLE SIZE
POTASSIUM
PULVERIZED FUELS
REACTION KINETICS
RESIDUES
SEMIMETALS
SILICON
SIZE
SODIUM
SOLS
STAGED COMBUSTION
SURFACE PROPERTIES
SYNTHESIS
THERMOCHEMICAL PROCESSES
TIME DEPENDENCE
TRACE AMOUNTS
TRANSITION ELEMENTS
WASTES
ZINC