Influence of Crude Source on the Structural Indices of Short Residue

Production of bitumen for paving purposes is a complex operation at the refinery considering the variability in the crude source. At any instant of time, refineries process a blend of different crudes, and the associated process parameters are varied in real time to maximize the throughput of the lighter ends. Such changes influence the chemical composition of the short residue. To quantify such changes, three different crude sources (Arab Mix, Kuwait, and Assam) were identified, and FTIR spectroscopy was used to characterize them. The variability across different crudes and different short residue obtained from the respective crudes and the relation between the crude and the short residue were quantified in terms of the structural indices such as factor of aliphaticity, aromaticity index, carbonyl index, sulfoxide index, and condensation indices. It was seen that the structural indices from crude oil to short residue were related and the relationship varied between the three different crude sources. Inter-relationships among different indices such as aliphaticity, aromaticity, branching, and condensation were observed, and the relationship among the crude and short residue for these indices was reported.