Simultaneous production and recovery of volatile fatty acids from fermentation process using an electrochemically assisted up-flow granular sludge bed reactor

Juan Castilla-Archilla*, Danfei Zeng, Yifeng Zhang*, Piet N.L. Lens

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

108 Downloads (Pure)

Abstract

A continuous production and in-line recovery of volatile fatty acids (VFAs) was developed by coupling an electrochemical cell (EC) to the recycling line of an up-flow anaerobic sludge bed (UASB) reactor. The use of an easy fermentable feedstock (glucose) was proposed for a fast production of VFAs. The EC allowed the simultaneous recovery of VFAs while producing alkali equivalent and hydrogen brought to the reactor, allowing to decrease caustic addition and promoting VFA production. Duplicate systems were used with glucose at an initial concentration of 15 g/L for Phases I to III, and increased to 60 g/L in a stepwise manner during Phase IV to VI. The EC was connected using 3.5 V to the UASB reactor at Phase III (15 g/L glucose, hydraulic retention time (HRT): 24 h), decreasing by 46% the VFA concentration in the reactor mixed liquor and the sodium hydroxide consumption by 49%. The highest VFA concentration in the anode chamber was 4.6 times higher than in the reactor. The highest caproic acid production achieved corresponded to 6.01 g/L during Phase IV (30 g/L glucose, HRT: 24 h). At the end of the trial, the voltage was increased up to 6.0 V and the water addition in the anode chamber was stopped to build up the VFA concentration, reaching 27.80 and 28.05 g/L for EC1 and EC2, respectively. The coupled UASB-EC system showed promising results in terms of good recovery of the VFAs from the fermentation broth, decrease of the alkali demand and caproic acid production.
Original languageEnglish
Article number109568
JournalJournal of Environmental Chemical Engineering
Volume11
Issue number2
Number of pages10
ISSN2213-3437
DOIs
Publication statusPublished - 2023

Bibliographical note

Funding: This work was supported by the Science Foundation Ireland (SFI) Research Professorship Programme Innovative Energy Technologies for Biofuels, Bioenergy and a Sustainable Irish Bioeconomy (IETSBIO3, award no. 15/RP/2763) and the Research Infrastructure research grant Platform for Biofuel Analysis (Grant Number 16/RI/3401) as well as the National University of Ireland, Galway by the Thomas Crawford Hayes Award Research & Travel Fund 2021.

Keywords

  • Up-flow anaerobic sludge bed
  • High strength feedstock
  • Acidogenesis
  • Electrochemical cell
  • Volatile fatty acid recovery

Fingerprint

Dive into the research topics of 'Simultaneous production and recovery of volatile fatty acids from fermentation process using an electrochemically assisted up-flow granular sludge bed reactor'. Together they form a unique fingerprint.

Cite this