Combustion of CWF agglomerates from pulverized or micronized bituminous coal, carbon black, and diesel soot

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Combustion and Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(94)90173-2· OSTI ID:6852423

Atal, A; Levendis, Y A ^[1]

---

1. Northeastern Univ., Boston, MA (United States). Dept. of Mechanical Engineering

Fundamental studies were conducted to explore the role of coal grind size on the combustion characteristics of coal-water fuel (CWF) agglomerates. The agglomerates were prepared from bituminous coals of two different grind sizes: (40 [mu]m, and 4[mu]m) mean size as well as blends thereof. Additional experiments were performed with predried agglomerates from water slurries of carbon black or diesel soot. All agglomerates were in the size range of 150--900 [mu]m and were either plain or impregnated with calcium magnesium acetate (CMA). Upon heating and devolatilization, the bituminous coal agglomerates studied were found to melt, mildly swell, and form cenospheric structures. Individual pulverized coal particles also form small cenospheres themselves, superimposed on large agglomerate-derived cenospheres. Combustion of CWF agglomerates, in the size range examined, occurred with distinct volatile and char combustion phases with the latter burning in a diffusion-controlled mode. The combustion behavior of pulverized and micronized coal agglomerates of the same size was strikingly similar. The presence of dissolved CMA accelerated setting of the slurries and, upon water evaporation it suppressed melting and cenospheres formation of the coal particles and agglomerates alike. Also, CMA mildly influence the agglomerate combustion behavior, causing both larger volatile flames and char temperatures that peaked at the first half of the burnout period and decreased thereafter, but did not substantially affect the char burnout time. Carbon black and diesel soot agglomerates did not form cenospheres and the latter burned a little hotter and faster but, basically, their combustion was similar to that of CWF chars. Bulk fragmentation was consistently observed only in the case of CMA-impregnated carbon black agglomerates.

• OSTI ID: 6852423
• Journal Information: Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 98:4; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
02 PETROLEUM
025000 -- Petroleum-- Combustion
ADDITIVES
AGGLOMERATION
BITUMINOUS COAL
BLACK COAL
CARBON
CARBON BLACK
CARBONACEOUS MATERIALS
CHEMICAL REACTION KINETICS
COAL
COMBUSTION KINETICS
DIESEL FUELS
DISPERSIONS
DISTILLATES
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUEL SLURRIES
FUELS
GAS OILS
HYDROGEN COMPOUNDS
KINETICS
LIQUID FUELS
MATERIALS
MICROSPHERES
MIXTURES
NONMETALS
OXYGEN COMPOUNDS
PARTICLE SIZE
PETROLEUM
PETROLEUM DISTILLATES
PETROLEUM FRACTIONS
PETROLEUM PRODUCTS
REACTION KINETICS
SIZE
SLURRIES
SOOT
SUSPENSIONS
WATER