Sweeping Gas Membrane Distillation (SGMD) as an Alternative for Integration of Bioethanol Processing: Study on a Commercial Membrane and Operating Parameters

This article considers the application of the sweeping gas membrane distillation process (SGMD) for direct separation of ethanol-water using a flat sheet PTFE membrane. It also studies the effect of operating parameters including feed concentration, feed temperature, feed flow rate, and sweeping gas flow rate on the permeation flux and selectivity of ethanol/water. The results showed that the increase in feed temperature increases in permeate flux and selectivity. Selectivities of 18.5 to 25 were achieved using dilute feeds within the temperature range of 35 to 55°C. However, by increasing the feed concentration by more than 5 wt.%, the selectivity was decreased. The increase in permeation flux and ethanol selectivity at higher feed flow rates was mainly due to the reduction of polarization effects. Moreover, the PTFE membrane was characterized by AFM. The results showed that the present process could be used as a stand-alone technique for bioethanol process integration. Keywords: Ethanol-water mixtureMorphologyPermeate fluxPTFE membraneSweeping gas membrane distillation (SGMD) Acknowledgment The authors thank the Young Researchers and Elites Club (Omidieh Branch, Islamic Azad University) for its financial support of this work. Notes Note: HF: hollow fiber; FS: Flat sheet. a Reported by the manufacturer. b @ 23°C for air with methanol. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gcec.