Influence of vacuum degrees in rectification system on distillation characteristics of bio-oil model compounds

The batch distillation experiments of bio-oil model compounds were carried out in a pilot rectification column. The distilled fractions of bio-oil model compounds at atmospheric pressure and vacuum distillation were compared by changing the vacuum degree in the system, and the variations of each component in the fractions were analyzed and summarized. The results showed that the total distillate rate of bio-oil model compounds increased and the coking rate decreased, the water was more likely to be evaporated, the initial distillation temperature of organics in the fraction decreased and the distillation rate increased with the decrease of vacuum degree in the system. Therefore, increasing the vacuum degrees can effectively separate the components of the bio-oil model compounds and reduce the energy loss. When the vacuum degree is −0.08 MPa, the distillation effect of the bio-oil model compounds are optimum. The distillation rates of acetic acid and furfural can reach 99.50% and 65.88%, and the distillation rates of phenol and guaiacol both exceed 25%.