精馏系统内真空度对生物油模型化合物蒸馏特性的影响

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

利用小试精馏装置对生物油模型化合物进行蒸馏实验,通过调节系统的真空度将生物油模型化合物分别在常压和减压状态下进行蒸馏,分析并总结了馏分中各组分的变化规律。结果表明,随着系统内真空度的不断升高,生物油模型化合物的总馏出率不断增加且结焦率不断降低,水分更容易被蒸出,馏分中有机物的初馏温度降低而馏出率增加。因此,增大真空度可有效分离生物油模型化合物的组分并降低蒸馏的能量损耗;当真空度为−0.08 MPa时,生物油模型化合物的蒸馏效果最好,其中,乙酸和糠醛的馏出率分别可达99.50%和65.88%、苯酚和愈创木酚的馏出率为25.19%和26.17%,均超过25%。

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 show that the total distillate rate of bio-oil model compounds increases,the coking rate decreases,the moisture is more likely to be evaporated,the initial distillation temperature of organics in the fraction decreases,and the distillate rate increases with the rise in the vacuum degree of 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 is optimum.The distillate rate of acetic acid and furfural can reach 99.50%and 65.88%,respectively,and the distillate rates of phenol and guaiacol are both over 25%.