Enrichment of aromatic compounds during the high-pressure reactive distillation of bio-oil

The bio-oil produced from the renewable biomass is a sustainable source of aromatic compounds. The aromatic compounds in bio-oil would generally contribute to the coke formation during its further processing, which is a bottleneck problem for its further application due to the complex composition of bio-oil. In this study, the distribution and reaction of aromatic compounds during the high-pressure reactive distillation of bio-oil are investigated to achieve the enrichment of aromatic compounds to the distillate fraction. It is found that pressure could help transfer aromatic compounds into the distillate fraction. In addition, the increase of pressure could contribute to the reduction of polymerisation and the production of aromatic monomers due to the hydrothermal environment. Besides the process parameters, methanol could also be used to inhibit the polymerisation of aromatic compounds. Furthermore, the transfer of aromatic compounds could also be intensified using Ca(OH)₂ based on the acidity of phenolic compounds.