CHARACTERIZATION OF COAL TARS PRODUCED UNDER DIFFERENT CARBONIZATION CONDITIONS BY FT-IR SPECTROSCOPY AND EXTROGRAPHY

Coal tars produced by carbonization of wet charges of one coal blend o n industrial and semi-industrial scales with different mean flue tempe ratures and from a preheated charge of the same blend were studied. Th ese tars were characterized by FT-i.r. and H-1 n.m.r. spectroscopy in addition to the standard analytical methods. They were also separated by extrography into fractions differing in chemical functionality, whi ch were examined by FT-i.r. spectroscopy and g.c.-m.s.. Differences we re mainly observed in the proportions of polynuclear aromatic hydrocar bons and nitrogen-containing heteroaromatics. The information can be u sed as an indicator of the severity of thermal cracking during tar for mation in a coke oven.