Key words: supercritical water, native asphaltite, conversion products, composition
Natural asphaltite and the products of its conversion in supercritical water (400 °С, 40 MPa) are comparatively analyzed using a complex of methods including analyses of elemental and component compositions, pyrolytic and X-ray diffraction analyses, spectrophotometry, IR-, EPR-spectroscopy and gas chromatography/mass spectrometry. It is demonstrated that under indicated conversion conditions of asphaltite various products, such as gases, carbene-carboids; heavy, highly resinous and sulfur-rich petroleum are produced. The yields of the conversion products are roughly identical. The obtained petroleum and carbene-carboids are characterized by lower sulfur and oxygen content and higher content of nitrogen and paramagnetic centers as compared to the initial asphaltite. Components of the same names (oils, resins and asphaltenes) composing petroleum and asphaltite noticeably differ by the content of heteroatoms (elemental analysis), aromatic and carbonyl-containing structural fragments (IR-spectroscopy). The analysis of molecular compositions of hydrocarbon and heteroorganic compounds present in oils of the obtained petroleum evidence that compositions of nearly all classes of compounds substantially differ from those present in the initial asphaltite other reasons apart — due to the appearance of new compounds. The revealed differences are mainly caused by the generation of such compounds via thermal destruction of resin-asphaltene substances. The process prolongation from 0.5 to 1 hour causes noticeable changes both in the yields of the main groups of products and in the compositions of the most of analyzed compounds.
doi:10.1134/S1990793111080021