Molecular Representation of Molecular Distillation Cuts of Vacuum Residue by Spectrometry Ultra-High Resolution and Conventional Analytic

Abstract

A set of 200 representative molecules for a Vacuum residue (VR) fractionated with molecular distillation (MD) was obtained. A built in-house wiped film molecular distillation unit that operates in continuous mode at pressures below 1E-5 Pa was used to fractionate a Colombian heavy VR, four cuts were obtained changing the temperature of the system. First, each cut was characterized by conventional analytical, using conventional standardized methodologies (ASTM Methods). Second, each cut was characterized by ultra-high mass resolution spectrometry, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), combination of positive electrospray ionization ((+)ESI), negative electrospray ionization ((-)ESI) and positive atmospheric pressure photoionization ((+)APPI). Information obtained was employed for reconstruction and generation of set molecules that represents the original vacuum residue by contribution methods. A multi-feed strategy was used; it was based on a same set of representative molecules for each cut of MD but changing its composition among them. Optimization of molecular composition was obtained with simulated annealing. The error in estimation of bulk properties was lower than five percent when the FT-ICR-MS data was incorporated as input information.