Process optimization studies for the dehydration of alcohol–water system by inorganic membrane based pervaporation separation using design of experiments (DOE)

• Published in: Separation and purification technology 2010-02, Vol.71 (2), p.192-199
• Main Authors: Wee, Shin Ling, Tye, Ching Thian, Bhatia, Subhash
• Format: Article
• Language: English
• Subjects: Alcohols; Alcohol–water mixture; Applied sciences; Ceramic membrane; Chemical engineering; Design of experiments (DOE); Exact sciences and technology; Flow rate; Flux; Membrane separation (reverse osmosis, dialysis...); Membranes; Optimization; Penetration; Permeation; Pervaporation; Selectivity
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2009.11.021

In the present study, commercial ceramic membrane from Pervatech BV was used to study the dehydration of isopropanol–water mixture by pervaporation. The effects of feed temperature, feed concentration, permeate pressure and feed flow rate on the membrane separation performance were studied by using design of experiments (DOE) coupled with response surface methodology (RSM). The center composite design (CCD) was used to obtain optimum process condition. The results showed that in order to obtain optimum permeation flux and selectivity, the temperature, feed concentration of alcohol, permeate pressure and feed flow rate were 75 °C, 94 wt%, 1 kPa and 84 dm 3/h, respectively. Under optimum operating condition, the permeation flux and selectivity was 2.41 kg/m 2 h and 1131, respectively. The optimum permeation flux of 9.16 kg/m 2 h was obtained at temperature of 90 °C with feed concentration 81 wt% alcohol, permeate pressure of 1 kPa and feed flow rate of 100 dm 3/h, respectively. However, the optimum selectivity of 1415 was observed at the temperature of 69 °C, feed concentration 96 wt% alcohol, 1 kPa permeate pressure and feed flow rate of 41.05 dm 3/h, respectively. The effect of operation time on the performance of the membrane was also investigated by running the pervaporation process for 8 h continuously. It was observed that the permeation flux changed with time but the selectivity remained nearly constant after 8 h of continuous pervaporation.