Membrane‐assisted vapor stripping: energy efficient hybrid distillation–vapor permeation process for alcohol–water separation

Abstract

BACKGROUND: Energy efficient alternatives to distillation for alcohol recovery from dilute solution are needed to improve biofuel sustainability. A process integrating steam stripping with a vapor compression step and a vapor permeation membrane separation step is proposed. The objective of this work is to estimate the energy and process costs required to make a fuel grade ethanol (0.5 wt% water) from 1 and 5 wt% ethanol aqueous streams using the proposed process.

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).…”

Extremophiles in biofuel synthesis

“…One of these is that most strains are sensitive to high ethanol concentrations [4,25]. This could be overcome by the continuous removal of ethanol as it is being produced, facilitated by the high volatility of the product at higher temperatures [25,71], or by engineering a strain tolerant to higher ethanol concentrations. Another negative aspect is the low ethanol yields produced, due to the formation of by-products such as lactate and acetate [25,70].…”

Poly(vinyl alcohol)/ZIF‐8‐NH2 mixed matrix membranes for ethanol dehydration via pervaporation

“…The typical separation process involves distillation near to the azeotropic point, followed by zeolite 3A adsorption or a steam membrane process using organic or zeolite 4A membranes. [8][9][10] However, this process is generally operated under high temperature and consumes a lot of heat energy. Alternatively, pervaporation process is a very promising technology as it can be operated under moderate working conditions.…”