Characteristics of chars produced by pyrolysis following rapid heating of pulverized coal. [104 references]

Technical Report · Tue Feb 01 00:00:00 EST 1977

DOI:https://doi.org/10.2172/5029849· OSTI ID:5029849

Nsakala, N.; Essenhigh, R. H.

A 5.08-cm id pyrolysis furnace has been used to study pyrolysis following rapid heating of size graded pulverized coal particles as a function of isothermal pyrolysis time (0.018 to 1.025 second), particle size (50 to 181 ..mu..m), and parent coal (three lignites). The following experimental conditions were kept constant: Coal feed rate approximately equal to 0.5 g/min; volumetric flow rate of nitrogen temperature = 808/sup 0/C, and pressure = atmospheric. Under these conditions the heating rate of the coal particles in the pyrolysis furnace was of the order of 8 x 10/sup 3/ /sup 0/C/second. The experimental results show: (i) a monotonic change in the physical properties of chars with increasing pyrolysis time; (ii) some dependence of weight loss (i.e. VM yield) on particle size; (iii) that the three lignites undergo pyrolysis to a comparable extent, presumably because of their similar initial chemical composition; (iv) an appreciable influence of temperature and heating rate on weight loss in the Parr VM crucible; and (v) a significant influence of the mode of pyrolysis (i.e. entrained vs fluid bed) on the nature of the char produced. The results from a theoretical treatment of the problem of gas-solid interactions suggest that, in the pyrolysis furnace, all coal particles smaller than 200 ..mu..m in diameter are heated from their initial room temperature to the predetermined gas temperature of 808/sup 0/C so fast that no appreciable gradient is established between their surface and their center.

• Research Organization: Pennsylvania State Univ., University Park (USA). Coal Research Section
• Sponsoring Organization: USDOE
• DOE Contract Number: EX-76-C-01-2030
• OSTI ID: 5029849
• Report Number(s): FE-2030-TR2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
CHARS
PHYSICAL PROPERTIES
COAL
PYROLYSIS
DENSITY
HEATING RATE
INFRARED SPECTROMETERS
MICROSTRUCTURE
POROSIMETERS
POROSITY
SURFACES
X-RAY DIFFRACTION
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DECOMPOSITION
DIFFRACTION
ENERGY SOURCES
FOSSIL FUELS
FUELS
MEASURING INSTRUMENTS
SCATTERING
SPECTROMETERS
010406* - Coal & Coal Products- Pyrolysis & Cracking- (-1987)
010600 - Coal
Lignite
& Peat- Properties & Composition