Products of conversion of sulfur-rich native asphaltite in supercritical water

Natural asphaltite and the products of its conversion in supercritical water (400°C, 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 and EPR spectroscopy, and gas chromatography/mass spectrometry. It is demonstrated that the asphaltite conversion under the indicated conditions results in the formation of various products, such as gases, carbene-carboids, as well as heavy, highly resinous, and sulfur-rich petroleums. The yields of the conversion products are roughly identical. The obtained petroleum and carbene-carboids are characterized by lower sulfur and oxygen contents and a 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), as well as 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 attests to the fact that the compositions of nearly all classes of compounds substantially differ from those present in the initial asphaltite; among other reasons, due to the emergence of new compounds. The revealed differences are mainly caused by the generation of such compounds upon thermal destruction of resin-asphaltene substances in which they were present in a bound state. The prolongation of the process from 0.5 to 1 h results in noticeable changes both in the yields of the main products and in the compositions of most compounds analyzed.