Cleavage and crosslinking of polymeric coal structures during pyrolysis. Final report [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 1992.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 59 pages : digital, PDF file
- Additional Creators:
- SRI International, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- The ultimate objective of this project was to develop a better understanding of volatiles production to help optimize the yield and character of condensable coproducts during coal pyrolysis or mild gasification. The specific objectives were to (1) Develop pyrolysis procedures that minimize secondary reactions; and (2) Develop coal pretreatments that current knowledge suggests will prorate bond scission or prevent retrograde reactions. Our approach was to study the pyrolysis of coals and tar-loaded coals by using several techniques that span a range of heating rates and pressures. Slow-heating pyrolyses were performed at low pressures in the inlet of a field ionization mass spectrometer and at atmospheric pressures in a thermogravimetric analyzer. Moderately rapid-heating pyrolyses were performed in a vacuum TGA apparatus and in sealed silica ampules heated in a molten-salt bath. The fastest heating rates were achieved with laser pyrolysis at about 30,000 X/s. The high tar yield seen in this work where the entire volume of the coal particle becomes hot and fluid at very nearly the same time, taken together with the evident non-vapor transport of the tar under these conditions, emphasizes the importance of better understanding the development of fluidity during coal heating. This specifically includes the profound effects--long-recognized but poorly understood that mild oxidation has in suppressing coal fluidity. It also includes the more recently recognized fact that heating in the presence of an inert gas produced substantially greater fluidity than does heating in the presence of combustion gases, even if the conditions are very fuel rich and all the oxygen itself has already been consumed when the coal particles are encountered.
- Report Numbers:
- E 1.99:doe/mc/23286--3093
- Other Subject(s):
- Published through SciTech Connect.
Malhotra, R.; McMillen, D.F.
- Type of Report and Period Covered Note:
- Final; 01/01/1987 - 12/31/1992
- Funding Information:
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