Activated Carbon-Loaded Polydimethylsiloxane Membranes for the Pervaporation of 1-Butanol from Aqueous Solutions

Butanol has shown potential as an alternative biofuel. It can be obtained through ABE fermentation, which produces 1-butanol, ethanol and acetone. Pervaporation is a potential separation process, since it can be successfully applied to remove trace components such as butanol, which is toxic to the cells. The development of an effective membrane is the limiting factor for this technology. Activated carbon-containing polydimethylsiloxane membranes were prepared by varying the filler content up to 2 wt%. The resulting membranes were characterized for the separation of model solutions with 1-butanol, acetone, ethanol and water by pervaporation. The effects of activated carbon load (0, 1, 2 wt%) and temperature (25, 40, 55ºC) on flux and separation factor were evaluated. The addition of 1 wt% activated carbon increased membrane free volume, changed surface morphology and showed flux of 45 g/m2h, with separation factor for 1-butanol of 370, at 55ºC.

丁醇已展现出作为替代生物燃料的应用潜力。其可通过ABE发酵制备，该过程可生成1-丁醇、乙醇与丙酮。渗透汽化（Pervaporation）是一种颇具前景的分离工艺，因其可有效脱除诸如丁醇这类对细胞具有毒性的痕量组分。开发高性能分离膜是该技术实用化的核心限制因素。本研究通过调整填料添加量最高至2 wt%，制备了含活性炭的聚二甲基硅氧烷（polydimethylsiloxane）膜。随后采用渗透汽化法，对所制备膜在含有1-丁醇、丙酮、乙醇及水的模型溶液中的分离性能进行了表征。考察了活性炭负载量（0、1、2 wt%）与操作温度（25、40、55℃）对膜通量与分离因子的影响。当操作温度为55℃时，添加1 wt%活性炭可增大膜的自由体积、改变膜表面形貌，此时膜通量可达45 g/(m²·h)，对1-丁醇的分离因子达370。