(69d) Carbon Nanotube Membranes for Separation of Fuels from Water

The application of carbon nanotube (CNT) membranes for the separation of water miscible fuels like alcohols from water is discussed. Previously separating alcohols like ethanol or butanol from water has been achieved through distillation followed by molecular sieves, an energy intensive thermal process typically requiring the combustion of fossil fuels. CNT membranes have recently been shown to achieve the same separation with much lower energy requirements. The CNT membranes are alcohol selective, permeating alcohols while rejecting water transport, in room temperature pervaporation and vapor permeation modes of operation. Very high alcohol concentrations, in some cases anhydrous alcohols, are achieved in single pass extractions using only vacuum and condensation. Experimental data at the pilot scale will be discussed, including data from the direct air capture and conversion of CO2 to transportation fuels.