Large-particle coal devolatilization and tar production from lump coal. Volumes I and II

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1981

OSTI ID:6179867

Kalson, P A

Theoretical and experimental studies of coal devolatilization and tar production were carried out. The fundamental chemical and physical processes which occur during coal devolatilization were examined in the theoretical study. The study includes all large-particle conditions (i.e. those for which physical effects are important) as well as lump coal devolatilization. Single lumps or a small number of lumps of coal were lowered into a pre-heated 1-inch diameter stainless steel pipe through which hot nitrogen was flowing. Heating of the coal was by convection from the gas flowing past the sample and by radiation from the walls. Tar yields were obtained for the devolatilization of a caking Pittsburgh No. 8 high-volatile. A bituminous coal in the range of 15 to 50 psia. Tar yields were generally higher than those in a fixed-bed gasifier; the differencs between the experimental devolatilizer and the fixed-bed gasifier were discussed. Tar yield increased from 9.1% to 13.3% when the superficial gas velocity was increased from 0.3 to 2.4 m/s. Tar yield underwent a broad maximum at around 500/sup 0/C and coke decreased with temperature over the range of 430 to 550/sup 0/C. There appears to be a reduction in tar yield with an increase in lump size from 3 to 15 g (1.7 to 2.8 cm), although the difference over the range employed was comparable to the data variability. No effect of pressure on tar yield was observed because of the limited range employed in this study. Tar production peaked earlier than gas production, and the products of tar decomposition were coke and gas in the ratio of 4 to 1.

• Research Organization: Michigan Univ., Ann Arbor (USA)
• OSTI ID: 6179867
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010406* -- Coal & Coal Products-- Pyrolysis & Cracking-- (-1987)
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
DECOMPOSITION
DEVOLATILIZATION
ENERGY SOURCES
FOSSIL FUELS
FUELS
HEATING
MATERIALS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PACKED BED
PARTICLE SIZE
PRODUCTION
SIZE
TAR