(Sup 1)H CRAMPS (Combined Rotation and Multiple-Pulse Spectrometry) NMR Investigation of the Organic Surface Composition and Organic Mineral Interactions of Chemically and Thermally Treated Asphalt Ridge Tar Sand: Final Topical Report

摘要

An exploratory investigation was conducted using the advanced NMR technique CRAMPS (combined rotation and multiple-pulse spectrometry) to provide information on the types of organic functionality via hydrogen types present on the surface of tar sand residues. The solvents hexane, toluene, and methylene chloride were used to extract the bitumen from the native tar sand. All three solvents removed essentially all of the bitumen from the mineral matrix. However, the solid-state sup 1 H NMR and diffuse reflectance infrared have shown the presence of a small amount of organic material still in contact with the mineral matrix. Tar sand residues after extraction with methylene chloride contain less organic material than the tar sand residues obtained after solvent extraction with hexane. The hydrogen spectra of the residues show a greater amount of aromatic hydrogens than aliphatic hydrogens. Of interest were the relatively large amounts of hydrogen caused by (1) alkyl hydrogens adjacent to ketone carbonyl functionality, (2) hydrogens of methylene groups bridged between aromatic rings, and/or (3) hydrogens of methyl and ethyl substituents on aromatic rings. The infrared data on the extracted tar sand residue also show a relatively large amount of ketone functionality. The spectra of the residues obtained from the isothermal and nonisothermal pyrolysis of the native tar sand show that a relatively large amount of bitumen still remains with the mineral matrix even at a temperature of 380 C (716 F). Above 400 C (752 F) the (sup 1)H spectra changed dramatically but still do not have the (sup 1)H resolution that was apparent in the spectra of the tar sand residues from solvent extraction. The major change in the (sup 1)H spectra of the tar sand residues after pyrolysis above 400 C was the loss of paraffinic hydrogens. 75 refs., 10 figs., 2 tabs. (ERA citation 14:002811)