Non-catalytic liquefaction of bitumen with hydrothermal/solvothermal process

Bitumen was mainly obtained as a residue of the petroleum refining process. In fact, bitumen is of great importance to the chemical industry because of the wide variety of special properties, which has favored the development of a wide field of applications. The development of process has been proposed to recover chemical resources from bitumen that can accomplish the destruction of the bitumen into harmless to produce useful compounds. In this work, an upgrading process for bitumen and its model compounds were investigated in supercritical water and solvothermal process by using batch reactor. It was well known that water at the hydrothermal condition is considered a promising and an environmentally acceptable solvent for a wide variety of chemical reactions such as organic syntheses and decomposition of hazardous wastes into harmless compounds. The experiments were conducted at temperature of 673 K and at various reaction pressures. Instead of water, benzyl alcohol (BZA) was used as a solvent in solvothermal process at temperatures of 523–573 K. The chemical species in the liquid products were analyzed by gas chromatography mass spectrometry. The effect of pressure and reaction time on the decomposition process was presented. Ultimate analysis of solid residue was also conducted using a CHN analyzer. Moreover, this method could become an efficient method for upgrading bitumen into harmless and high yield of valuable chemical intermediates on the basis of the experimental results.

TG analysis of bitumen before treatment by using supercritical water or subcritical BZA (TG/DTA; SII nanotechnology; EXSTAR-6000).Figure optionsDownload as PowerPoint slideHighlights
► Pentane, hexane, heptane, and dodecane were used as solvents to determine the content of maltene and asphaltene in bitumen.
► Upgrading of bitumen was carried out in supercritical water at 673 K and solvothermal treatment with BZA as a solvent at 523–573 K.
► The products were analyzed by GC-MS, MALDI-TOF-MS, FTIR, TG/DTA, and elemental analysis.