Abstract:The short path distillation has been widely used in purification and refining of food additives for its advantages of short heating time, high separation efficiency and preservation of the natural actives. Accurate prediction of separation purity and separation efficiency play an important role in parameters optimization and experiment design of short path distillation process. The citronellal was separated from citronella oil by short path distillation in this work and the corresponding multicomponent mass transfer model, which simulated the separation process, was established based on Langmuir-Kundsen equation. The effects of different process conditions on the purity and separation efficiency of citronellal were predicted, and the simulation results were consistent with the experimental data. The results showed that the separation of citronellal was mainly processed in the front, nearly middle part of the evaporator (z/L = 0.5), with a ultimate separation efficiency of 60%. Increasing feeding rate, decreasing evaporating temperature or evaporation area was beneficial for the purification of citronellal, while reduced the separation efficiency. Based on the results of purity and separation efficiency of citronellal, the optimum process conditions were as follows: feeding rate, 4~5 mL/min; temperature, 65~70 ℃.
