Impact of osmotic agent on the transport of components using forward osmosis to separate ethanol from aqueous solutions

Abstract

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. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4499–4507, 2017

Forward Osmosis as Concentration Process: Review of Opportunities and Challenges

“…Using a similar membrane, different results were obtained by Ambrosini et al who demonstrated the possibility to preferentially removing alcohol from a feed solution (dealcoholisation). This study performed with lower initial alcohol concentration in the feed (5%) described how draw selection can impact relative alcohol/water passage through the membrane, organic draw solutes being preferred to favour alcohol permeation [ 69 ]. The same research team also investigated the impact of membrane type (CTA and TFC membranes from HTI) on the separation process [ 70 ].…”

Beer aroma recovery and dealcoholisation by a two-step pervaporation process

“…Such beverages can be made using biological and physical methods. With the latter, several approaches have been reported including pervaporation , vacuum distillation , thin film evaporation , dialysis , reverse osmosis , spinning cone column distillation , osmotic distillation , membrane distillation and forward osmosis . All those methods have intrinsic disadvantages, the most common of which is the loss of aromatic volatile compounds, which usually exceed 75% of higher alcohols and 95% of esters , resulting in beer with reduced alcoholic, solvent and fruity aromas .…”