Investigation of gas stripping and pervaporation for improved feasibility of two-stage butanol production process

摘要

Gas stripping and pervaporation are investigated for butanol recovery in a two-stage acetone-butanol-ethanol (ABE) fermentation process. The first stage is operated in a continuous mode and the second stage as a fed-batch. Gas stripping coupled to the second stage and operated intermittently enabled additional glucose feeding in the second stage and up to 59. g/L butanol and 73. g/L total ABE solvents in the condensate. Concentration of 167. g/L butanol and 269. g/L ABE in the permeate was measured in ex situ pervaporation experiments using a PDMS membrane at temperature of 37. °C and pressure of 10. mbars. The " operating window" tool is introduced to evaluate the feasibility of the existing ABE fermentations operated as continuous with cell recycle, as two-stages, with biomass immobilization or with integrated product removal. This tool enables the identification of the most favorable process configuration, which is the combination of cell immobilization and integrated product removal.