Enhancing pyrolysis oils’ thermal stability by supercritical carbon dioxide as a solvent
Supercritical carbon dioxide can be used as a solvent and a reactant. Hrncic et al. stated that carbon dioxide can solve pyrolyis oils and mixtures that contained pyrolysis oil. If supercritical carbon dioxide can be used as a solvent for pyrolysis oils this would possibly lower the pyrolysis oil’s viscosity, slow down polymerization reaction velocity and thereby enhance its thermal stability before upgrading.
Gas solubility measurements were conducted for a variety of gases and media like ionic liquids or petroleum products. Thus an apparatus is under construction that is able to measure gas solubilities by the pressure decay of one gas within a reservoir cell while the gas is floating into an equilibrium cell that contains the pyrolysis oil. From a comparison of the measured values with values when no gas is solved follows the gas solubility. Since carbon dioxide has many advantages as a solvent because of its non-toxic and non-flammable properties and its readily accessible critical parameters (Tc = 31 ◦C, pc = 74 bar) it is even though pos ... mehrsible that it will react with components of the pyrolysis oil. It can also be discussed that it might enhance the hydrogen solubility within oils as certain gas solubilities in organic liquids can be increased in supercritical solvents. This can improve upgrading steps in hydrogen atmosphere.