Separation Of 1-Propanol From Aqueous Solution By Using Liquid-Liquid Extraction Method

1-Propanol is an important organic solvent,it is also an indispensable raw material for synthetic esters.And it is widely used in the fields of cosmetics and rubber synthesis.The dehydration of 1-propanol is an important step in obtaining high-purity 1-propanol.However,the mixtures of(1-propanol+water)can form minimum azeotrope at T=360.15 K.It is difficult to obtain high-purity 1-propanol by using traditional distillation method.Liquid–liquid extraction is an effective method to separate azeotropic mixtures.The key to this technology is the use of extract agents with high extraction performance.Dibutyl ether(DBE)and sec-butyl acetate(SBAC)have low water-solubility,low vapor pressure,and low volatility,which can better meet the principle of selecting extract agents.Thus,this paper explored the feasibility by using DBE and SBAC as extracting agents to extract1-propanol.Liquid-liquid equilibrium(LLE)of binary(water+DBE),(water+SBAC)systems and ternary(water+1-propanol+DBE),(water+1-propanol+SBAC)systems were measured at T=(293.15,298.15,303.15,308.15)K and p=100 kPa.Distribution coefficients and separation factors were used to assess the extraction performance of DBE and SBAC to extract1-propanol from aqueous solution.The separation factors of the ternary systems(water+1-propanol+DBE)and(water+1-propanol+SBAC)are(13.9449-144.4736)and(19.1353-92.5854),respectively.It means that both DBE and SBAC can be consider as good solvents for extracting 1-propanol from aqueous solution.In this work,the modified and extended UNIQUAC models were employed to correlate the experimental LLE data.The average rmsd values of correlated results of ternary systems are 0.63mol%and 1.55 mol%for the modified and extended UNIQUAC models,respectively.It is obvious that the two models both show good accuracy and applicability to calculate the experimental LLE.The consistency of the measured LLE data was ascertained by applying the Othmer-Tobias,Hand and Bachman equations.The values of R~2 for each equation are more than0.97.It further proves the high reliability of LLE data measured in this work.