Study On Composition And Structure Of Residues From Several Sources

The chemical composition and structure of residues of PL19-3R and Oil sand bitumen OSR series were studied by means of physical instrument analysis combined with chemical oxidation degradation.The percentage of saturates, aromatics, resins and asphaltenes obtained from residue samples were investigated. By means of the modified Brown-Ladner's method, the average structural parameters of the residues and their fractions were calculated based on proton magnetic resonance spectroscopy combined with infrared spectroscopy, elementary analysis and average molecular weight determination. The results show that the residues of PL19-3R series possess high resins content but low asphaltenes content, and the residues of Oil sand bitumen OSR series possess quite low saturates content, quite high asphaltenes content, and relative low resins content. The saturates content and aromatics content of residues both decrease and the resins content increases after direct solvent deasphalting, while the asphaltenes content of PL19-3R residues changes slightly and the asphaltenes content of Oil sand bitumen OSR residues increases. The saturates content and aromatics content both decrease remarkably and the asphaltenes content increases remarkably after first visbreaking and then solvent deasphalting, while it effects the resins content of PL19-3R residues slightly and the resins content of Oil sand bitumen OSR residues also decreases obviously. The H/C atomic ratios of residues of two series are quite low. Especially the H/C of Oil sand bitumen OSR residues is less than 1.4 entirely. The aromaticty fA and the average molecular weight increase, the fraction of paraffinic carbon fP and the H/C atomic ratios decrease in the order of saturates, aromatics, resins and asphaltenes.The analysis of GC-MS for RICO oxidation products indicates that PL19-3R and Oil sand bitumen OSR series residue samples possess C6~C29 and C5~C25 n-alkyl side chains attached to aromatic carbons separately. They also possess C2~C7 and C2~C8 polymethylene moieties linking two aromatic units separately. Futher more, various benzenepolycarboxylic acids (from di- to hexacarboxylic acids) were detected from the RICO products of all the residue samples, which indicates that the presence of pericondensed aromatic structures. Quantitative analysis indicates that the orders of the content of all kinds of n-alkyl side chains of PL19-3R and Oil sand bitumen OSR series residue samples are D#>4#>E#>C#>B#>A# and 03#>02#>2#>1#>3#, and the result of aromaticty by the quantitative analysis of n-alkyl side chains is accord with the result calculated from average structural parameters. The orders of the content of all kinds of polymethylene moieties are D#>E#>B#>4#>C#>A# and 03#>02#>1#>2#>3#, which indicates the abundance of aromatic structures connected by polymethylene bridges is different. In addition, D#>A#>4#>E#>B#>C# and 03# > 02# > 1# > 2# > 3# are the orders of the content of various methyl benzenepolycarboxylates (from di- to hexacarboxylic acids), which reflects the abundance and condensation of aromatic units are different.The analysis of carbon mass distribution about all the residue samples shows that the carbon mass in CO2 and organic phase is the most. The analysis result of ESI-MS confirms that the analysis result of GC-MS is credible.