title: Upgrading of straw hydrolysate for production of hydrogen and phenols in a microbial electrolysis cell (MEC).
abstract: In a microbial electrolysis cell (MEC), hydrolysate produced by hydrothermal treatment of wheat straw was used for hydrogen production during selective recovery of phenols. The average H₂ production rate was 0.61 m³ H₂/m³ MEC·day and equivalent to a rate of 0.40 kg COD/m³ MEC·day. The microbial community in the anode biofilm was adapted by establishment of xylose-degrading bacteria of the Bacteriodetes phylum (16%) and Geobacter sulfurreducens (49%). During the process, 61% of the chemical oxygen demand was removed as hydrogen at 64% yield. The total energy production yield was 78% considering the energy content in the consumed compounds and the cell voltage of 0.7 V. The highest hydrogen production was equivalent to 0.8 kg COD/m³ MEC·day and was obtained at pH 7-8 and 25°C. Accumulation of 53% w/v phenolic compounds in the liquor was obtained by stepwise addition of the hydrolysate during simultaneous production of hydrogen from consumption of 95% for the hemicellulose and 100% of the fatty acids. Final calculations showed that hydrolysate produced from 1 kg wheat straw was upgraded by means of the MEC to 22 g hydrogen (266 L), 8 g xylan, and 9 g polyphenolics for potential utilization in biobased materials.
authors.affiliation: Technical University of Denmark, Roskilde, Denmark. athy@risoe.dtu.dk
authors.forename: Anders
authors.initials: A
authors.lastname: Thygesen
authors.forename: Massimo
authors.initials: M
authors.lastname: Marzorati
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
authors.forename: Anne Belinda
authors.initials: AB
authors.lastname: Thomsen
authors.forename: Willy
authors.initials: W
authors.lastname: Verstraete
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001674:Bioelectric Energy Sources; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004572:Electrolysis; D004591:Electrophoresis, Polyacrylamide Gel; D006859:Hydrogen / Q000378:metabolism*; D008969:Molecular Sequence Data; D009691:Nucleic Acid Denaturation; D010636:Phenols / Q000378:metabolism*; D010802:Phylogeny; D018547:Plant Stems / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010636:Phenols; D012336:RNA, Ribosomal, 16S; D006859:Hydrogen