Kinetics of Biochar Liquefaction

The renewable resource pyrolysis char hereinafter often referred to as biochar, produced by pyrolysis or hydrothermal carbonization, has promising properties for advanced upgrade. Technologies for the conversion of biochar to biofuels may therefore contribute to suffice the growing demand for fuel. Direct liquefaction of biochar is a conceivable way of producing biofuels. Direct liquefaction of biochar was carried out in a 450 ml batch reactor at a temperature of 425 °C with the hydrogen donor solvent tetralin. Biochar conversion of 84 % and an oil yield of 72 % were observed after 33 min of reaction time. Compared to fossil coal liquefaction, the hydrogenation of biochar leads to a diverse product distribution with more oil products and less intermediates. In process modeling, intermediates as well as products and residues of similar product properties according to their solubility in different organic solvents were identified. These product classes formed the basis for investigation of kinetics of biochar liquefaction. The reaction route network resulting from the reaction scheme was solved with a FORTRAN algorithm.