Biological Hydrogen Gas Production from Food Waste as a Sustainable Fuel for Future Transportation

In the global search for the right alternative energy sources for a more sustainable future, hydrogen production has stood out as a strong contender. Hydrogen gas (H₂) is well-known as one of the cleanest and most sustainable energy sources, one that mainly yields only water vapor as a byproduct. Additionally, H₂ generates triple the amount of energy compared to hydrocarbon fuels. H₂ can be synthesized from several technologies, but currently only 1% of H₂ production is generated from biomass. Biological H₂ production generated from anaerobic digestion is a fraction of the 1%. This study aims to enhance biological H₂ production from anaerobic digesters by increasing H₂ forming microbial abundance using batch experiments. Carbon substrate availability and conversion in the anaerobic processes were achieved by chemical oxygen demand and volatile fatty acids analysis. The capability of the matrix to neutralize acids in the reactors was assessed using alkalinity assay, and ammonium toxicity was monitored by ammonium measurements. H₂ content was also investigated throughout the study. The study's results demonstrate two critical outcomes, (i) food waste as substrate yielded the highest H₂ gas fraction in biogas compared to other substrates fed (primary sludge, waste activated sludge and mixed sludge with or without food waste), and (ii) under normal operating condition of anaerobic digesters, increasing hydrogen forming bacterial populations, including Clostridium spp., Lactococcus spp. and Lactobacillus spp. did not prolong biological H₂ recovery due to H₂ being taken up by other bacteria for methane (CH₄) formation. The experiment was operated under the most optimal condition for CH₄ formation as suggested by wastewater operational manuals. Therefore, CH₄-forming bacteria possessed more advantages than other microbial populations, including H₂-forming groups, and rapidly utilized H₂ prior to methane synthesis. This study demonstrates H₂ energy renewed from food waste anaerobic digestion systems delivers opportunities to maximize California’s cap-and-trade program through zero carbon fuel production and utilization.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References;
  • Pagination: 32p

Subject/Index Terms

Filing Info

  • Accession Number: 01853345
  • Record Type: Publication
  • Report/Paper Numbers: 22-35, CA-MTI-2141
  • Contract Numbers: ZSB12017-SJAUX
  • Files: NTL, TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jul 29 2022 9:17AM