Carbon nanotube enhanced membrane distillation with air sparging for economic separation of biofuels from fermentation products

Carbon Nanotube Enhanced Membrane Distillation with Air Sparging forEconomic Separation of Biofuels from Fermentation ProductsPI: Cheng Li NanoSepex Inc. Newark NJ 07103The objective of this project is to develop carbon nanotube (CNT) enhanced membranedistillation (MD) for the recovery of ethanol in biofuel industry. In MD a hydrophobic porousmembrane separates a warm fermentation product feed and a permeate stream.As thefermentation products pass on the membrane the ethanol is partially transformed to its vapor.The hydrophobicity of the membrane prevents the aqueous solution from entering the membrane.However freed from hydrogen bonding the ethanol passes through and is collected as aconcentrate. The novel membrane referred to as carbon nanotube immobilized membrane(CNIM) will be developed by immobilizing functionalized CNTs into membrane pores toselectively transport ethanol vapor. The CNIM along with a modified MD process thatincorporates air sparging (or CNIM-MD) will be used for the economic recovery of biofuels. Ourpreliminary data shows that the CNIM-MD can be carried out at relatively low temperatureso o between 40 to 70 C as compared to 80 to 90 C for thermal distillation. CNIM-MD will lead tothe lowering of capital expenditure operating cost and it will facilitate the recovery of ethanolfrom low concertation waste streams. Its low temperature operation will allow the utilization ofindustrial waste heat and solar energy and prevent the formation of harmful byproducts duringbiofuel processing. The proposed tasks are: 1. Membrane development based on CNTfunctionalization; 2. Ethanol recovery via CNIM-MD with air sparging; 3. Configuration ofCNIM-MD modules for maximizing recovery and process design; 4.Integration of CNIM-MDwith thermal distillation and pervaporative dehydration.