Hydrocarbon Composition of the Products of Thermal and Catalytic Cracking of Asphaltenes Obtained in Supercritical Water

The hydrocarbon composition of oils from asphaltene cracking products was studied. The experiments were carried out in three different modes: without additives (a control experiment without water and catalyst), in supercritical water without catalyst, and in supercritical water with an iron oxide–based catalyst. Cracking was carried out in a reactor at 450°C; the experiment duration was 60 min, and the catalyst was obtained in situ from iron(III) tris(acetylacetonate). Individual hydrocarbon composition of oils isolated from cracking products was determined by gas chromatography–mass spectrometry (GC–MS) analysis using a Shimadzu GCMS-QP5050A quadrupole system. The hydrocarbon composition of asphaltene cracking products obtained in supercritical water differed in qualitative and quantitative characteristics from the products obtained without water. Upon asphaltene cracking in water, the composition changed significantly compared to that in the control experiment, and an increase in the fraction of saturated hydrocarbons was noted. In cracking products obtained in an aqueous medium with the addition of a catalyst, saturated hydrocarbons also predominated, while the concentration of phthalates, alkenes, and sulfur-containing compounds increased significantly.