Continuous removal of ethanol from dilute ethanol-water mixtures using hot microbubbles

Abstract

Highlights Continuous removal of ethanol from dilute mixtures using hot-microbubbles. Ethanol concentration maintained below the inhibition threshold for organism TM242. An ethanol productivity up to 14.9 g L −1 h −1 was supported by the stripping unit.

Ethanologenic fermentation by Parageobacillus thermoglucosidasius with continuous hot microbubble gas-stripping

“…4). Based on the total volume within the system and allowing for the ethanol remaining in the bioreactor gives an effective stripping rate of 0.83 g/L.h for stage II (based on the actual recovery, or 0.88 g/L.h based on assumed yields), which is significantly less than the stripping rates produced in our previous study with pure ethanol-water mixtures (~ 10-20 g/L.h) [27]. In addition to the low concentration driving force for mass transfer, this result is likely due to a combination of several factors.…”

“…The calculated average ethanol generation rates with operating parameters can be used to estimate the average ethanol concentration in the MSU (not measured), based on our previous work [27]. The design equation is,…”

Reprogramming a high robustGeobacillus thermoglucosidasiusfor efficient synthesis of polymer-grade lactic acid under extremely high temperature (60°C)

“…The copyright holder for this preprint this version posted April 14, 2023. ; https://doi.org/10.1101/2023.04.14.536835 doi: bioRxiv preprint promising compounds at elevated temperatures, such as bioethanol 18,47,[52][53][54][55] , isobutanol 56 , 2,3-butanediol 57 , terpenes 32 , and riboflavin 22,58 . However, the production of these compounds is limited to the laboratory and cannot be scaled up for industrial production, mainly because of low product titers.…”

Effects of Operational and Geometric Variables of a Bubble Column Bioreactor on Ethanol Stripping with CO2: Liquid and Gas-Phase Monitoring

“…This configuration avoids the adverse effect of the hot microbubbles in the physiology of the microorganism and allows the operation of the stripping unit under the optimum conditions in terms of liquid height in order to maintain an ethanol concentration below the inhibitory level, resulting in higher productivities. 35 On the other hand, the operation of the bioreactor with in situ stripping promotes the removal of heat from the cultivation broth together with ethanol and water, decreasing the cooling water consumption during the fermentation, which reduces costs associated with cooling water treatment and equipment maintenance, as reported by Almeida et al 13 However, further studies with technical and economic evaluation are required to compare the performance of ex situ and in situ stripping using both batch and continuous modes.…”