Acetone-butanol-ethanol fermentation products recovery: Challenges and opportunities

Nowadays, global warming is one of the most significant concerns in modern societies, which entails considerable costs to the environment, health, economy, etc. Fossil fuels play an essential role in this phenomenon and finding an alternative for them has been the research topic for the past few decades. Among the array of options available, biofuel stands out as a highly effective and environmentally sustainable alternative. Biobutanol presents properties like high heating value, low volatility, high viscosity, and low corrosion. Additionally, it is a much safer option for use, and its ability to blend with gasoline and other fuels turns it into a suitable and promising renewable alternative. Biobutanol can be produced from the agricultural industry's residues by the acetone-butanol-ethanol (ABE) fermentation process. The separation and purification of biobutanol from the fermentation broth account for 40 % of the plant budget, which is notable. Various separation techniques like liquid-liquid extraction, membrane perstraction, gas stripping, vacuum flash, membrane pervaporation, thermopervaporation, reverse osmosis, adsorption, etc., are applied. A befitting separation method must produce sufficient butanol concentration in the output and reduce the final product's cost so biobutanol can compete economically with other fuels. This work reviewed the existing processes for the separation and purification of butanol from ABE fermentation, including advanced methods. All methods will be discussed in detail considering environmental and economic parameters and each technique's superiors and challenges.