Perpustakaan Digital ITB

Recently, membrane pervaporation has gained acceptance by the chemical industry as an effective process for separation and recovery of liquid mixtures. It is currently best identified with dehydration of liquid hydrocarbons to obtain high-purity organics, most notably ethanol. It can easily be integrated into distillation, to separate water-ethanol azeotrope mixture that always be the problem in distillation. The objective of this research are to design and construct pervaporation prototype, study of the direct effect of temperature and downstream pressure on pervaporation performance, and to develop pervaporation unit based on theoretical calculation. The membrane used in this study is commercial hydrophilic crosslinked Poly(vynil alcohol) or PVA composite membrane. Although the cast membrane may be packed in module in several geometris, plate and frame is generally used. The effective membrane area used in this study is 98 cm2 per stage in multistage design. The operating parameters were varied in the range between 25 to 70oC for temperature and 5 to 30 mbar for permeate pressure. The temperature and downstream pressure strongly influence the pervaporation characteristic. Solubility and diffusifity of the feed components in membranes are generally influence by temperature and downstream pressure. The visual appearance of temperature effect is membrane swelling. The permeation rate increases significantly for each 10oC temperature increment. The optimum condition of this experiment was obtained at temperature 50oC and permeate pressure 5 mbar. The flux and selectivity at optimum condition were 0.505 kg/m2.h and 30, respectively. The enrichment of ethanol from 95.6 wt % to 99.5 wt % (Q = 0.6 I/h) was obtained using 1.1 stages with 1078 cm2 total membrane area.