In the present work, a new method based on 1 H NMR spectroscopy has been developed for the estimation of total aromatics and their distribution as mono-and polynuclear (di-ring plus) aromatics in diesel-range fuel products. Multipulse NMR techniques such as, distortionless enhancement by polarization transfer and 2-dimensional heteronuclear correlation have been applied for the unambiguous assignment of the 2.0-3.5 ppm region due to R-substituents on the aromatic ring in the 1 H NMR spectra. The estimation of polynuclear aromatics is based on the estimation of bridgehead aromatic (Ar b ) and substituted aromatic (Ar q ) carbons using equations developed. The proposed 1 H NMR-based method correlates very well with the standard IP-391/ 90-and mass-spectrometric-based method (R 2 ) 0.99).

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Jatropha curcas has been considered as a material of choice in India for the production of bio-diesel and a very large area has been planted in India. For better growth, Jatropha plants need extensive pruning once a year, and the pruning of a healthy two year old plant on an average gives about 4–6 kg of lignocellulosic material (LCM). Jatropha prunings can be available in significant amount on annual basis. These prunings have no other use and this material has potential to be an economical and suitable LCM for conversion to fermentable sugars, as these contain considerable amount of holocellulose. In this study, acid pretreatment of Jatropha pruning was carried out using dilute sulfuric acid. A wide range of variables, i.e., acid concentrations from 2.50% to 10.0%, temperature from 120 to 180 °C, and reaction time of 5–45 min were studied. Three response factors, namely, maximum xylose release, minimum inhibitors, and maximum enzymatic digestibility, were optimized by application Taguchi design. Pretreatment efficiency was determined by enzymatic saccharification and physico-chemical properties of both native and pretreated biomass analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. This study provides insights into the intricacies involved in conversion of this biomass to fermentable sugars. These studies indicate that Jatropha prunings can be converted economically into ethanol and can provide additional support to Jatropha based bio-diesel programme.