producing fuel-grade bioethanol. In general, the enrichment of
ethanol by a one-stage pervaporation process cannot result in fuelgrade
product. It will be shown how can be reached the endproduct
with the desired quality by means of consecutively applied
hydrophilic and hydrophobic pervaporation. To obtain a product
with about 99.5 wt% ethanol concentration, several stages can be
needed to be combined. The main task of this study is to predict the
energy demand of distillation and pervaporation under various
feed concentration, product concentrations and separation factor
values and to show under what conditions pervaporation can be a
viable alternative to distillation for producing fuel-grade ethanol.
In this paper
firstly the specific energy demand of distillation and
pervaporation is discussed for production of fuel-grade bioethanol,
applying the fermentation broth with different ethanol concentration
and then brief cost estimation of the production will be
given.