Patent ID: 9490109
Filing Date: 2016-11-08
CPC Classification: G01N,H01J

Claim Text:
1. A method to determine the model-of-composition of a sample of petroleum resid comprising: (a) separating the resid sample into asphaltenes and deasphalted oils (DAO) and separating the deasphalted oils (DAO) into chemical meaningful classes including saturates, aromatics, sulfides and polars; wherein said aromatics are separated into aromatic ring class fractions including 1-ring aromatics (ARC1), 2-ring aromatics (ARC2), 3-ring aromatics (ARC3), 4-ring+ aromatics (ARC4+); (b) obtaining molecular ions or pseudo molecular ions of each of the asphaltenes, separated DAO and separated classes using a combination of Atmospheric Pressure Photoionization (APPI) or Atmospheric Pressure Chemical Ionization (APCI) and Field Desorption/Field Ionization and Electrospray Ionization (ESI) in high resolution mass spectrometry; wherein using ESI includes using positive ion electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (PEST FTICR-MS) to ionize basic nitrogen molecules and by means of negative ion electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (NEST FTICR-MS) to ionize acidic molecules; (c) determining elemental formula and assigning structure of said molecular ions or pseudo molecular ions and quantifying their corresponding concentrations in the asphaltenes, separated DAO and separated fractions from the high resolution mass spectrometry; and (d) combining compositions of separated fractions from act (c); (e) directly measuring bulk properties, average structures, and molecular weight distribution of the resid, asphaltenes and separated DAO and separated fractions; (f) minimally adjusting the molecular compositions obtained from acts (a)-(d) to match the properties the directly measured by act (e) to obtain a model-of-composition.