2004 Volume 83 Issue 1 Pages 56-63
Using gas-chromatography, the authors developed a unique technique called ‘NPgram’ to characterize the hydrocarbon fuel oil. The notation ‘NPgram’ stands for Normal Paraffin gram.
It is obtained by plotting the weight percent of a group of hydrocarbons, which are located within the range of retention values of two successive normal paraffins (Cn-1 and Cn), against the carbon number (n). As the carbon number (n) corresponds to the boiling point range of a group of compounds, NPgram (C-NPgram) actually represents a boiling point distribution, when it is applied for fuel oils composed of aliphatic compounds.
In this work we applied this C-NPgram technique to characterize coal derived oils which are mostly composed of aromatics. And analogous to C-NPgram, the carbon number distributions of S, N, Cl and O-compounds in coal derived oils were also shown. We defined them by ‘S-NPgram’, ‘N-NPgram’, ‘Cl-NPgram’ and ‘O-NPgram’. The NPgrams of these heterogeneous compounds were obtained by plotting the amount of heterogeneous compounds determined by a GC-AED (Atomic Emission Detector) against the carbon number (n).