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 07103.The objective of this project is to develop carbon nanotube (CNT) enhanced membrane distillation(MD) for the recovery of ethanol in biofuel industry. In MD a hydrophobic porous membraneseparates a warm fermentation product feed and a permeate stream.As the fermentation productspass on the membrane ethanol is partially transformed to its vapor.The hydrophobicity of themembrane prevents the aqueous solution from entering the membrane. However freed fromhydrogen bonding the ethanol passes through and are collected as a concentrate. The novelmembrane referred to as carbon nanotube enhanced membrane (CNEM) will be developed byimmobilizing functionalized CNTs into membrane pores to selectively transport ethanol vapors.The CNEM along with a modified MD process that incorporates air sparging (or CNEM-MD) willbe used for the economic recovery of biofuels. Our preliminary data shows that the CNEM-MDo o can be carried out at relatively low temperatures between 40 to 75 C as compared to 78 to 117 Cfor thermal distillation. CNEM-MD will lead to the lowering of capital expenditure operating costand it will facilitate the recovery of ethanol from low concertation waste streams. Its lowtemperature operation will allow the utilization of industrial waste heat and solar energy andprevent the formation of harmful byproducts during biofuel processing. The proposed tasks are: 1.Fabrication of large area membranes for ethanol separation; 2) Development of large spiral woundCNEM-MD modules with integrated air sparging; 3). System development at pilot plant scale; and4) Field Demonstration at biofuel production plant.