基于乙醇协同作用的柠檬油提取废液中挥发性芳香物的渗透汽化膜分离性能研究

Improving the Pervaporation Separation of Aromatic Components from Lemon Oil Processing Waste Liquid by the Synergistic Effect of Ethanol

采用涂布法自制了聚二甲基硅氧烷/聚偏氟乙烯树脂(Polydimethylsiloxane/Polyvinylidene Fluoride,PDMS/PVDF)渗透汽化复合膜,用于柠檬精油加工废液中挥发性芳香物的渗透汽化分离。考察了复合膜对橙花醇、α-松油醇和芳樟醇等三种柠檬精油废液中特征性芳香物的渗透汽化分离性能,结果显示,复合膜对3种化合物具有很好的分离选择性,但渗透通量均较低。添加乙醇对芳香物的分离效果有显著影响,当乙醇添加量为5%V/V时,橙花醇和芳樟醇的渗透通量较未加乙醇时提高了82.93%和127.76%,而α-松油醇的渗透通量则随着乙醇浓度的升高先升高后缓慢下降。测试了PDMS/PVDF复合膜对实际柠檬油废液中挥发性芳香物的分离效果,经渗透汽化处理6 h后,柠檬油废液中挥发性芳香物的种类及含量均明显降低,橙花醇、α-松油醇和芳樟醇的回收率分别为92.5%、93.37%、60.36%,应用效果良好。

A PDMS/PVDF pervaporation composite membrane was self-made via the coating method and used for separating volatile aromatic compounds from the waste liquid of lemon essential oil processing by pervaporation(PV).The PDMS/PVDF membrane was applied in the pervaporation separation of nerol,α-terpineol,and linalool,which are characteristic aroma components in lemon essential oil waste liquid.The results demonstrated that the PDMS/PVDF membrane had good separation selectivity for the three compounds,but the permeation flux was low.Addition of ethanol significantly affects the separation of aromatics.When the amount of ethanol added is 5%v/v,the permeation fluxes of nerol and linalool increase by 82.93%and 127.76%over those without ethanol.The permeation flux ofα-terpineol first increased and then decreased slowly with the increase in ethanol concentration.In addition,the performance of the PDMS/PVDF membrane in separating volatile aroma components in actual lemon oil waste liquid was tested.When the experiment was conducted for 6 h,the types and content of volatile aromatic compounds in the lemon oil waste liquid were significantly reduced.The recovery rates of nerol,α-terpineol,and linalool were 92.50%,93.37%,and 60.36%respectively.The results showed that the PDMS/PVDF membrane achieved better performance.