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U.S. Department of Energy
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Catalytic coal conversion support: use of laser flash-pyrolysis for structural analysis. Progress report, April 1-June 30, 1980

Technical Report ·
OSTI ID:5752427
Acid lignin was pyrolyzed and the pyrolysis products analyzed on the HP model 5830 GC/MS to increase our understanding of the pyrolysis process. Lignin is a high molecular weight polyphenol whose detailed structure is not known, but is believed to be constructed from phenylpropane derivatives. Consequently, if condensed ring compounds like indene and naphthalene are observed in the pyrolysis products of lignin, ring closure may be taking place during pyrolysis. The lignin was pyrolyzed with the Nd laser and the CO/sub 2/ laser, yielding significantly different pyrograms. Pyrolysis with the Nd laser yielded more than 30 products of which the major components are diacetylene and methoxyphenol. Acetylene was not detected. Pyrolysis with the CO/sub 2/ laser yielded more than 96 compounds. Products occurring in greater than 10 ..lambda.. relative abundance included benzene, toluene, styrene, and napthalene. Although both lasers produced CS/sub 2/, the CO/sub 2/ laser produced several sulfur-containing organics not observed with the Nd laser: thiophene, methylthiophenes, dimethylthiophenes, and benzothiophenes. The Nd laser produced acetylenic compounds not observed with the CO/sub 2/ laser: 1 buten-3-yne, diacetylene, and phenylacetylene. Similar aromatic and phenolic compounds were observed with both lasers. The presence of indene, naphthalene, and benzothiophene in the lower-energy CO/sub 2/ laser pyrolysis indicates that some ring-closing reactions are taking place. The greater amounts of acetylenic compounds produced by the Nd laser are most likely a result of the higher energy deposition by this laser.
Research Organization:
Los Alamos National Lab., NM (USA)
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
5752427
Report Number(s):
LA-9032-PR; ON: DE82004176
Country of Publication:
United States
Language:
English