"Prompted by the need of non-petroleum-based fuels, coal research has reemerged... Pyrolysis research... has gained... momentum because of its close connection to combustion, hydropyrolysis and liquification. Spectroscopic and other instrumental techniques are... producing... information about coal structure and pyrolysis mechanisms, while modeling efforts are breaking new ground in sorting out chemical and physical phenomena... [P]ostulates and assumptions of current work provide a meaningful starting point in... theoretical descriptions of greater validity and applicability."