Investigation of the coal devolatilization: kinetics and product characterization

Technical Report · Wed Sep 01 04:00:00 EDT 1982

OSTI ID:6040376

Freihaut, J D; Seery, D J; Zabielski, M F

The objectives of this program are to develop an operational understanding and model of coal devolatization with respect to the relative influence of the following parameters: chemical characteristics of the parent coal, ambient pressure, applied heating rate, and final temperature achieved by the coal particles. Tar formation and release is given particular attention since previous investigations (DOE Contract ET-78-C-01-3167) indicated tar evolution to be an important aspect of coal devolatilization that is often given insufficient attention. This investigation indicated that the tar formation phase of coal devolatilization occurs very early in the transient heating phase of coal devolatilization. For mvBit and lower rank coals, tar formation can occur at temperatures as low as 450/sup 0/C. Under the ambient pressure conditions, tar evolution precedes light gas evolution for bituminous coals. In these conditions the tar evolution rate appears to heat transfer controlled. As ambient pressure is increased the tar yields are significantly decreased, indicating a transition to mass transfer control of tar evolution. Tar yields and thermal stability of tar species are highly dependent on the chemical characteristics of the parent coal. Coals of the same ASTM rank but of varying aromaticity have different tar yields and tars of varying degrees of thermal stability. In this connection, infrared characteristics of the parent coal are of immediate assistance in predicting the tar evolution behavior of a coal. Char and light gas yields are coupled to the fate of primary tars in the tar evolution process. A first approximation model of coal devolatilization is presented with the stated reservations that more detailed studies of heat and mass transfer effects on tar evolution are needed.

• Research Organization: United Technologies Research Center, East Hartford, CT (USA)
• DOE Contract Number: AC21-81MC16221
• OSTI ID: 6040376
• Report Number(s): DOE/MC/16221-1372; ON: DE83008270
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010406* -- Coal & Coal Products-- Pyrolysis & Cracking-- (-1987)
010600 -- Coal
Lignite
& Peat-- Properties & Composition
CARBONACEOUS MATERIALS
CHARS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
COAL
COAL RANK
COAL TAR
DATA
DEVOLATILIZATION
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDS
FOSSIL FUELS
FUELS
GASES
HEATING RATE
INFORMATION
INFRARED SPECTRA
KINETICS
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PYROLYSIS PRODUCTS
PYROLYTIC GASES
REACTION KINETICS
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
TAR
TEMPERATURE DEPENDENCE
YIELDS