Molecular composition of Tanitoharm coal liquid light distillates was thoroughly analyzed using GC-MS, NMR and IR techniques for the identification of nitrogen compounds in the hydrotreated coal liquid. The remaining nitrogen species after the hydrotreatment were concentrated by narrow cut distillation to be identified as (1) decahydro-pyrrolo [2,1,5-de] quinolizine and (2) tetradecahydro-9b-aza-cyclopenta [def] phenanthrene that stayed refractory for HDN in the hydrotreatment.
