Conversion of Pyrolysis Products into Volatile Fatty Acids with a Biochar-Packed Anaerobic Bioreactor


Küçükaǧa Y., Facchin A., Kara S., Naylr T. Y. , Scicchitano D., Rampelli S., ...More

Industrial and Engineering Chemistry Research, vol.61, no.45, pp.16624-16634, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 61 Issue: 45
  • Publication Date: 2022
  • Doi Number: 10.1021/acs.iecr.2c02810
  • Journal Name: Industrial and Engineering Chemistry Research
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Applied Science & Technology Source, Aqualine, Chemical Abstracts Core, Chimica, Compendex, Computer & Applied Sciences, zbMATH, DIALNET
  • Page Numbers: pp.16624-16634
  • Kocaeli University Affiliated: No

Abstract

© 2022 American Chemical Society. All rights reserved.The coupling of pyrolysis and acidogenic fermentation was here proposed as a new hybrid thermochemical-biological method to circumvent the hydrolysis bottleneck within lignocellulose valorization schemes. Pyrolysis products of fir sawdust, that is, the water-soluble (WS) fraction together with CO-rich syngas, were tested as feedstock for volatile fatty acid (VFA) production. WS/syngas conversion to VFA was particularly challenging due to the combined effect of the substrate (WS/syngas) and product (VFA) inhibition. To solve such an issue, a new type of bioreactor, based on packed biochar and a new acclimatization/bioaugmentation procedure consisting of co-feeding WS/syngas and glucose were developed and tested. The gradual switch from glucose to WS was monitored through various analytical techniques, observing the transition toward a "pyrotrophic" microbial mixed culture able to convert WS/syngas into VFA. Even without selective inhibition of methanogens, the main fermentation products were VFA (mainly acetic, butyric, and caproic acid), whose profile was a function of the WS/glucose ratio. Although the achieved volumetric productivity was lower (<0.6 gCOD L-1d-1) than that observed in sugar fermentation, bioaugmented pyrotrophs could convert headspace CO, most of GC-MS detectable compounds (e.g., anhydrosugars), and a significant portion of non-GC-MS detectable compounds of WS (e.g., oligomers with MW < 1.45 kDa).