The Chatham demonstration: From design to operation of a 20m3/d membrane-based ethanol dewatering system

Reducing the Energy Demand of Cellulosic Ethanol through Salt Extractive Distillation Enabled by Electrodialysis

“…However, there is a drastic increase in the distillation energy demand as the ethanol concentration in the fermentation broth from cellulosic sources is relatively low (30,(37)(38)(39).…”

“…However, there are several key challenges in various areas of the biochemical conversion process that need to be addressed (3,8,9,11,25). In the product recovery area, the main disadvantage is the dilute nature of the fermentation broth with ethanol concentration varying from about 3 to 6 wt%, (2, 9, 10, 14, 26-29) compared to about 10 to 15 wt% for corn-ethanol (30)(31)(32)(33)(34). Recovering ethanol from fermentation broth and purifying to fuel grade is difficult and energy intensive because of the dilute nature of the fermentation broth and the challenging water-ethanol vapor liquid equilibrium (VLE) with an azeotrope at about 96 wt% ethanol and tangential approach of the water-ethanol equilibrium curve to the 45° line at high ethanol concentrations in the familiar y-x VLE diagram representation.…”

Reducing the energy demand of corn‐based fuel ethanol through salt extractive distillation enabled by electrodialysis

“…The state of the art technique used in the fuel ethanol industry to produce fuel ethanol is distillation close to the azeotropic composition followed by dehydration in a molecular sieve based adsorption unit 10,16,19,20 or, in some cases, distillation followed by dehydration with membrane vapor permeation. 15,21 Membrane-assisted vapor stripping was tested at the pilot scale level for producing fuel ethanol from a dilute ethanol feed (5 wt %), representing fermentation broth obtained from lignocellulosic feedstocks. 22,23 Green field facilities for producing fuel ethanol from lignocellulosic feedstocks are expected to be built to meet the requirements of EISA.…”

“…10,[15][16][17][18] The fermentation broth contains many components besides water and ethanol: unfermented biomass, microorganisms, proteins, oils, and volatile organics. Recovering ethanol from fermentation broth and purifying to fuel grade is difficult and energy intensive because of the dilute nature of the fermentation broth and the challenging water-ethanol vapor liquid equilibrium (VLE) with an azeotrope at about 96 wt % ethanol and tangential approach of the water-ethanol equilibrium curve to the 45 line at high ethanol concentrations in the familiar y-x VLE diagram representation.…”

Bioethanol Production from Steam Explosion Pretreated Straw

“…Membrane separation processes need much less energy for ethanol separation but are not in operation on an industrial scale. First results from a pilot plant using the Siftek TM membrane technology show a reduction of the energy required for dehydration of about 50% (Côté et al, 2010). Process and heat integration techniques also play an important role in energy saving in the bioethanol process (Alzate & Toro, 2006;Wingren et al, 2008).…”