Partial Least-Squares (PLS) Correlation between Refined Product Yields and Physicochemical Properties with the ¹H Nuclear Magnetic Resonance (NMR) Spectra of Colombian Crude Oils

Abstract

A method was developed, in which the integral areas of resonance signals in 12 regions of the 1 H nuclear magnetic resonance (NMR) spectra of 5 widely different Colombian crudes and a crude mixture were correlated with selected physicochemical properties and standard distillation cut yields. The crudes used ranged from very light to heavy aromatics, thus covering a wide range of chemical compositions. The relationship between the NMR spectra and the properties of interest was obtained with the partial least-squares (PLS) algorithm. High correlation values were obtained for all of the PLS models used. The R 2 values of the prediction models for the physicochemical properties and SimDis results were >0.95, while the CV- q 2 values fluctuated between 0.74 and 0.99. The properties of an unknown crude or crude mixtures can be obtained from their 1 H NMR spectra and the use of the PLS models developed in this work. The correlation method is very fast (1 h instead of several weeks) and much less costly than the conventional ones.