MRL and PLS Correlations between the 1H NMR Spectra of Vacuum Residues and the Deasphalting Conditions with the DMO Yields

The areas of signals present in 12 consecutive frequency bins of the 1H nuclear magnetic resonance (NMR) spectra of different vacuum residues (VRs) were correlated with the yield of the deasphalting/demetallization process (DEMEX) under fixed and variable conditions (antisolvent/load ratio and rectification temperature). Prediction models for the demetallized oil (DMO) obtained under variable process conditions generated by partial least squares (PLS) regression had R2 = 0.950 and the CV-q2 was 0.943. Models obtained with multiple linear regression (MLR) for the same process had R2 = 0.93 but with a significantly lower CV-q2 (0.608) value. The prediction models for the DMO yield under a set of fixed conditions was such that R2 = 0.930 for the PLS whereas for the MRL method it was 0.970. Again, the CV-q2 value was higher for the PLS (0.998) than for the MRL method (0.610). The proposed correlation methods are much faster and significantly less costly than the conventional ones used for predicting the yield of the DMO process.