Reduction of Wastewater Discharge toward Second-Generation Acetone–Butanol–Ethanol Production: Broth Recycling by the Fermentation–Pervaporation Hybrid Process

Abstract

To reduce the butanol fermentation wastewater (BFW) discharge and to address the difficulties in BFW treatment, a novel fermentation–pervaporation hybrid process was performed. After each batch of acetone–butanol–ethanol (ABE) fermentation, ABE in the fermentation broth was ex situ separated by pervaporation. The retentate was used as the buffer and the solution for the following batches of enzymatic hydrolysis and fermentation, respectively. Results showed that there were little negative influences of the phenols and acid inhibitors on the fermentation performances using the recycled BFW. Benefits from the process for BFW discharge reduction were obvious. After 4 cycles of BFW, ∼86% of the BFW was saved. Over 94% of ABE with concentrations of 42.5–50.2 g/L was recovered by pervaporation. Therefore, the novel process can effectively eliminate the disadvantage of large BFW discharge in the ABE fermentation processes.

Sequential catalytic lignin valorization and bioethanol production: an integrated biorefinery strategy

“…Generally, the pulp was mixed with 0.05 M H 3 PO 4 /KH 2 PO 4 buffer (adjusted pH to 4.8) at a solid to liquid ratio of 6 wt% or 12 wt%. The cellulase loading rate was 20 FPU/g (of glucan) [ 59 ]. After 72 h hydrolysis at 50 °C and 180 rpm, the liquid fraction was harvested by filtration and used as a substrate for bioethanol fermentation.…”

A new concept for total components conversion of lignocellulosic biomass: a promising direction for clean and sustainable production in its bio‐refinery

“…In recent decades, wastewater reuse has become a wise and promising alternative for industrial wastewater treatment . Recently, it was shown that the fermentation–pervaporation hybrid process could be used for ex situ separation of ABE in fermentation broth and the remaining broth could be applied for further enzymatic hydrolysis and fermentation, thus most of ABE fermentation wastewater could be saved . Furthermore, the ABE fermentation wastewater after treatment by absorption could be used for ABE fermentation again, and therefore the amount of wastewater could be reduced greatly …”

Recent Progress in Separation Membranes and Their Fermentation Coupled Processes for Biobutanol Recovery

“…The membrane materials should not only have good permeability (flux) and selectivity (separation factor), but also stability . In terms of the produced solvents’ (e.g., butanol) toxicity on the microbial cells, in situ solvent removal from the fermenter is favorable for enhancing the fermentation productivity. , Different from the sole biomass fermentation, in biobutanol fermentation integrated with the pervaporation process, the pervaporation membrane can selectively concentrate the fermented solvents in the permeate side, and meanwhile the nutrients and microorganism cells are retained in the fermentation broth …”

“…27,28 Different from the sole biomass fermentation, in biobutanol fermentation integrated with the pervaporation process, the pervaporation membrane can selectively concentrate the fermented solvents in the permeate side, and meanwhile the nutrients and microorganism cells are retained in the fermentation broth. 29 This review aims to present recent progresses in biobutanol production from the fermentation broth with different feedstocks by membrane pervaporation separation technology. Over the past decade, much work has been carried out to design and fabricate pervaporation membranes to enhance butanol/water property and membrane stability.…”