Transferable hydrogen by 1H nuclear magnetic resonance spectroscopy - Vital structural aspects of petroleum heavier ends (370-660 °C) feed stocks

In the present work, a direct and convenient method has been developed based on 1H Nuclear Magnetic Resonance (NMR) spectroscopic technique for the estimation of Transferable Hydrogen (TH), a necessary structural parameter of petroleum heavier ends feed stocks used for the various hydro processing techniques. The potential of the 1H NMR spectroscopic technique has been exploited for the identification and assignment of the signals in the chemical shift region corresponding to hydroaromatics. The method is based on the differentiation of α-hydrogen of hydroaromatics from the α-hydrogen of alkyl subtituents to aromatics in the chemical shift region of 2.45-4.45 ppm by the application of two dimensional (2D) NMR spectroscopic techniques. The derivation of mathematical equations based on this information allows the direct estimation of TH in the samples as such without their prior separation into aromatic and saturated fractions. This methodology is being utilized for monitoring the quality/selection of feed stocks for the production of desired value added products.