Structural evolution of matched tar-char pairs in rapid pyrolysis experiments

• Published in: Fuel (Guildford) Vol. 70; no. 3; pp. 414 - 423
• Main Authors: Pugmire, Ronald J., Solum, Mark S., Grant, David M., Critchfield, Scott, Fletcher, Thomas H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.1991
• Subjects: char; pyrolysis; tar; tar; char; pyrolysis
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/0016-2361(91)90132-T

Solid-state 13C and 1H nuclear magnetic resonance (n.m.r.) spectroscopy techniques were used to investigate the relationship between the chemical structure of coal and the char particles and condensed tar vapours produced from coals of various ranks at rapid heating conditions. The 13C n.m.r. analysis of the coal chars indicated that significant amounts of aliphatic material were released from the coal during devolatilization with little initial change to the aromatic cluster size or number of cross-links per cluster. The evolution of the char structure following tar release was a function of the temperature history of the char. The structure of the primary tars were compared to the parent coal, and the gas phase evolution of the tar structure was followed with time.