Understanding the dewatering of fermentation-based 1,3-propanediol with acetone before cyclohexanone synthesis

Abstract

Acetone can be produced by microbial fermentation using Clostridium acetobutylicum (acetone-n-butanol-ethanol fermentation, ABE fermentation), but it provides a mixture of acetone, 1-butanol, and ethanol. N-butanol and ethanol can be used as biofuels, but high-value applications of acetone generally require upgrading. Bio-based 1,3-propanediol is more readily produced by fermentation and separated at higher titers and has been used industrially. Therefore, the coupled upgrading of the two fermentation products can provide another avenue for high-value utilization of acetone. In this paper, salting-out extraction of 1,3-propanediol with acetone was carried out, and 1,3-propanediol and acetone would spontaneously form an organic phase, thus reducing the energy consumption in the 1,3-propanediol separation process. As the double alkylation reaction of acetone with equivalent 1,3-propanediol would generate cyclohexanone, the extraction of 1,3-propanediol with acetone can provide new insight into the process intensification (removing water, salt and water concentrated in the aqueous phase) for the 1,3-propanediol separation and conversion.