Critical studies of the rapid pyrolysis and hydropyrolysis of coal. Final project report, January 1, 1977-June 30, 1982

Technical Report · Wed Sep 01 00:00:00 EDT 1982

OSTI ID:6924548

Howard, J B; Peters, W A

This report summarizes major findings from a study of the effects of reaction conditions on the rapid pyrolysis behavior of coal in inert and hydrogen atmospheres. The independent effects of final temperature (150 to 1100/sup 0/C), reaction time at final temperature (0 to 30 s), heating rate (10/sup 2/ to 10/sup 4/ /sup 0/C/s), total pressure (0.0001 to 100 atm), hydrogen partial pressure (0 to 69 atm), and particle size (45 to 1000 ..mu..m), on product yields and compositions were determined for a Montana lignite and a Pittsburgh No. 8 Seam bituminous coal. Kinetic data were obtained for formation of specific pyrolysis products from each coal. A new mass transfer model for rapid hydrogasification of softening coal was also formulated. Effects of native mineral matter and selected inorganic additives on the pyrolysis behavior of the Pittsburgh Seam coal and of a Wyodak subbituminous coal were also studied. Detailed project findings are included in papers appended to the main body of the report. Important results include: (1) temperature and residence time are major parameters in determining pyrolysis and hydropyrolysis behavior; (2) coal type is also important, since major differences are observed in the yields, compositions, and evolution kinetics of products from rapid pyrolysis of the bituminous coal and of the lignite; (3) hydrogen can react rapidly with decomposing coal during the early stages of pyrolysis and, under conditions minimizing the elevated temperature contacting of hydrogen and pyrolysis tars, methane accounts for most of the resulting increased conversion; (4) secondary reactions of tar have a major role in determining product yields, compositions, and evolution kinetics in pyrolysis of the bituminous coal; and (5) increased CO production and decreased tar evolution are obtained by treating the bituminous coal with lime or calcite before pyrolysis.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA)
• DOE Contract Number: AT01-76ET10693
• OSTI ID: 6924548
• Report Number(s): DOE/ET/10693-2295; FE-MIT-2295T26; ON: DE83000101
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
CALCIUM COMPOUNDS
CATALYTIC EFFECTS
COAL
HYDROGENATION
PYROLYSIS
BITUMINOUS COAL
CATALYSTS
CHEMICAL REACTIONS
COAL TAR
HEATING RATE
HYDROGEN
LIGNITE
PARTIAL PRESSURE
PARTICLE SIZE
PRESSURE DEPENDENCE
SUBBITUMINOUS COAL
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
YIELDS
ALKALINE EARTH METAL COMPOUNDS
BLACK COAL
BROWN COAL
CARBONACEOUS MATERIALS
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
MATERIALS
NONMETALS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
SIZE
TAR
THERMOCHEMICAL PROCESSES
010406* - Coal & Coal Products- Pyrolysis & Cracking- (-1987)