Molecular Representation of Petroleum Vacuum Resid

Abstract

A novel methodology was extended for modeling the detailed composition of petroleum heavy vacuum resid fractions. The resid molecules were organized in terms of basic structural attributes: cores, intercore linkages, and side chains. The identities of the structural attributes were determined both from the extrapolation of chemical characteristics of light petroleum and the analysis of detailed mass spectrometric measurement of heavy resid fragmentation products. A building block library was constructed containing ∼600 attributes. The molecular composition was constructed by the combination of attributes, or building blocks, into discrete molecules. The quantitative abundance of each molecule was determined by the juxtaposition of a set of structural attribute probability density functions (PDFs) constraining pure hydrocarbon and heteroatom mixtures. Quantitative structure–property relationships (QSPRs) were applied to calculate the bulk properties of both the constructed molecules and the mixture. The adjustable parameters of the PDFs were determined using an optimization loop that employed an objective function that contained a term for each of the available analytical data points. The resulting optimal molecular compositions were in good agreement with the experimental structural information.

Lumped reaction kinetic models for pyrolysis of heavy oil in the presence of supercritical water

“…Although prominent progress has been made in structure oriented lumping, the lumping based on the traditional SARS separation has the advantages of the simple form and the clear definition of transformation . According to the reaction network recommended by Yasar et al, a simplified network involving the condensation of maltenes to asphaltenes and the condensation of asphaltenes to coke and gas as illustrated in Figure was adopted .…”

Insight into the structural features of Zhaotong lignite using multiple techniques

“…As a non-destructive technology, XPS analysis cannot provide detailed information on nitrogen occurrences in coals at molecular level. Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS), which possesses ultrahigh resolving power (>300,000) and mass accuracy (<1 ppm), has been widely used to characterize oxygen-and nitrogen-containing compounds in complex mixtures, such as petroleum [19][20][21], coal-derived liquids [22][23][24][25][26][27], and bio-oils [28,29]. Rathsack et al [23] investigated molecular composition of the liquid products from pyrolysis of a German lignite using electrospray ionization (ESI) FT-ICR MS. Their results exhibit that compounds detected are dominated by O x (x = 1-12) species and possible structures were proposed based on double bond equivalent (DBE, i.e., rings plus double bonds).…”

Identification of basic nitrogen compounds in ethanol-soluble portion from Zhaotong lignite ethanolysis by positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

“…Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) proved to be a powerful technique for molecular characterization of extremely complex samples, such as petroleum [20][21][22][23], coal-derived liquids [24][25][26][27][28], pyrolysis bio-oils [29][30][31], and dissolved organic matter in waste water [32]. It has an ultrahigh broadband mass resolving power (exceeding 200,000) and mass accuracy (<1 ppm), allowing for baseline resolution of closely spaced isobaric species as well as distinct assignment of a unique elemental composition to each mass spectral peak.…”