Highly efficient separation of butanol from acetone-butanol-ethanol solutions using integrated pervaporation-fractional condensation and superwetting membrane

Bio-butanol stands as a notable alternative fuel, predominantly produced through the acetone-butanol-ethanol (ABE) fermentation of saccharide substrates. However, the low concentration, intricate mixture, and azeotropic characteristics of the fermentation byproducts pose significant challenges, making the traditional separation process of biobutanol energy-intensive and expensive, thus hindering its industrial-scale application. This study introduces an innovative and eco-friendly separation process that integrates a pervaporation-fractional condensation (PV-FC) with a superwetting membrane (SWM). The PV-FC efficiently extracts ABE from the solution and effectively isolates n-butanol from acetone and ethanol, enabling Condenser 1 to yield a product primarily composed of n-butanol and water. Subsequently, in the SWM process, n-butanol and water are separated through salt-enhanced phase separation. Notably, n-butanol rapidly permeates through the membrane due to its nonpolar interactions with the SWM, resulting in an exceptionally high n-butanol content of 99.2 wt%. By integrating PV-FC and SWM, we have successfully achieved an environmentally friendly and efficient n-butanol separation process, offering substantial promise for practical n-butanol production.