Key words: heavy oil, supercritical water-oxygen fluid, activated carbon, oxidation, heat release
The composition of oily fractions (OFs) obtained at the heavy sulfur-rich oil conversion
is studied by means of physical and chemical methods of analysis. The oil was supplied
from the top into the vertical tubular reactor packed with activated carbon (AC),
where supercritical water-oxygen fluid was pumped from the bottom through the AC
bed. The experiment was performed at 30 MPa, temperature of upper, middle and
bottom parts of the reactor equal to 673, 723 and 723 K, variable flow rate of oxygen
(0—3.5 g/min) and constant flow rate of oil and water (4 and 6 g/min, respectively).
Based on the temporal trends in the reactor wall temperature and the power of
resistance heaters it is revealed that due to heat generation during the combustion of
oil high-molecular components, accumulated in the AC bed, the conversion process
occurs in autothermal mode. The movement of the combustion front along the reactor
axis is detected. It is shown that isoprenoids and normal alkanes, 1-alkyl-2,3,6-
trimethylbenzenes, alkyl-derivatives of benzo- and dibenzothiophenes are the main
components of the crude oil OF. The yield of OFs, whose portion in the liquid products
exceeds 90 %, has an extreme dependence on the oxygen flow rate. As the latter increases
and the temperature of the reaction mixture rises due to a heat generation upon
combustion, the relative content of bi- and tricyclic aromatic hydrocarbons alkylderivatives,
as well as benzo- and dibenzothiophenes in the OFs of conversion products
increases too. The content of fractions boiling at T < 493 K in the OFs of the conversion
product increases by 2—3 times compared to the crude oil OF.
doi:10.1134/S1990793118070035