COMPOSITIONAL STUDIES ON GAS OIL FRACTIONS USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Determination of chemical composition (hydrocarbon group type distribu tion) of distillates is of great relevance in predicting product quali ty. An h.p.l.c. method has been developed to determine total saturates , total aromatics and aromatic ring number distribution in straight-ru n gas oil fractions (250-370 degrees C) without prior separation, usin g refractive index and u.v. detectors. The absolute concentration of e ach hydrocarbon class type is determined from peak area percentages by applying response factors determined for each type, eliminating the e rror resulting from day-to-day fluctuation of operating parameters and non-reproducible injection etc. It is observed that all samples conta in nearly 70wt% saturates except Assam mix gas oil (56 wt%). Total aro matics (44%) and aromatic types (MA, DA and PA) are higher in Assam. C opyright (C) 1996 Elsevier Science Ltd.