AIChE Journal, Vol.63, No.10, 4499-4507, 2017
Impact of osmotic agent on the transport of components using forward osmosis to separate ethanol from aqueous solutions
The separation of low molecular weight organic compounds such as the ethanol from aqueous solutions represents an important area to be investigated and increment the range of applications of forward osmosis. This investigation assesses the effects of using different draw solutes for ethanol separation from dilute aqueous solutions. The influence of glucose, sucrose, sodium chloride, and magnesium chloride was evaluated in terms of total permeate, reverse solute and ethanol fluxes. Inorganic solutes promoted higher total permeate and ethanol fluxes than the organic solutes (2.5 and 1.5 times higher in average, respectively) for the same molar concentration, while presenting only 1.1 times higher reverse solute fluxes. Despite the lower ethanol flux promoted by the organic draw solutes, these osmotic agents promoted higher concentration of ethanol in the total permeate flux, suggesting that they can also be alternatives for specific processes. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 4499-4507, 2017
Keywords:ethanol;water separation;membrane separation processes;osmotic agents;osmotic pressure;draw solute