No abstract

Graphene-based laminate membranes have been theoretically predicted to selectively transport ethanol from ethanol-water solution while blocking water. Here, we report robust angstromchannel graphene membranes (ACGMs) fabricated by intercalating carbon sheets derived from chitosan into thermally-reduced graphene oxide (GO) sheets. ACGMs with robust and continuous slitshaped pores (an average pore size of 3.9 Å) were investigated for the dehydration of ethanol. Surprisingly, only water permeates through ACGMs in the presence of aqueous ethanol solution. For the water-ethanol mixture containing 90 wt.% ethanol, water can selectively permeate through ACGMs with a water flux of 63.8 ± 3.2 kg m -2 h -1 at 20 °C and 389.1±19.4 kg m -2 h -1 at 60 °C, which are over two orders of magnitude higher than those of conventional pervaporation membranes. This means that ACGMs can effectively operate at room temperature. Moreover, the ethanol can be fast concentrated to high purity (up to 99.9 wt.%). Therefore, ACGMs are very promising for production of bioethanol with high efficiency, thus improving its process sustainability.

No abstract

No abstract