Hydrogen and ammonia production from organic wastes

February 20th, 2024

We are trialling microbial strains, organic waste feedstocks and thermal hydrolysis in the production of hydrogen and ammonia via fermentation.

Project lead

Dr Andrew Beath, andrew.beath@csiro.au

Lead researchers

Anna Kaksonen, anna.kaksonen@csiro.au

Maneesha Ginige, maneesha.ginige@csiro.au

Ka Yu Cheng, kayu.cheng@csiro.au

Shaokun Song, shaokun.song@csiro.au

Challenge

Value recovery from biosolids can play a vital role in closing the loop for nutrients, water and energy used in our food and agriculture sector. We are investigating the potential for biological hydrogen production from organic wastes (biosolids, bagasse, sorghum, abattoir waste), thermally hydrolysed with concentrated solar thermal heat.

What we are doing

Leveraging CSIRO expertise in dark fermentation and applied industrial heat research, the multidisciplinary team is conducting trials using a selection of microbial strains and organic wastes to investigate an integrated approach to improve dark fermentation for hydrogen and ammonia production. Key features include:

The hydrolysis and dark fermentation process

  • Dark fermentation is microbially catalysed fermentative conversion of organic substrates to hydrogen in the absence of light and electron acceptors. It can be facilitated by a large range of microorganisms that differ in their optimal growth conditions.
  • The laboratory experiments evaluate whether thermal hydrolysis improves biological hydrogen generation rates and yields from selected organic waste materials. Thermal hydrolysis breaks down complex organic substrates making them more bioavailable for dark fermentation. Moreover, at elevated temperatures the thermal hydrolysis may also eliminate any unwanted hydrogen-consuming microbes, potentially improving hydrogen yields and production rates.
  • Strategies are developed to optimise metabolic pathways for enhanced biohydrogen production.
  • Concentrated solar thermal heat is considered for the thermal requirements of the process. This stage of the project is focused on investigating the potential benefits of thermal hydrolysis as a pre-treatment.

Waste to energy projects typically rely on cost effective access to waste residues (feedstocks) that are transported to a processing plant of sufficient scale to ensure economic feasibility. The integrated process also requires access to technically feasible and economically sourced heat with concentrated solar thermal energy a good option for regional areas.

Given these conditions, Mackay in Queensland, with an average yearly direct normal irradiance (DNI) of approximately 20 MWh/m2, has been chosen as a case study site. Apart from having a moderate source of solar irradiance, the site also has a reasonable size of population (> 80,000 people) that generates large quantities of municipal sewage sludge. This municipal waste stream, together with other biosolid waste streams such as bagasse, sorghum and abattoir wastewater generated from the surrounding agriculture and food industry, will be considered as the waste feedstocks in this project.

Outcomes to date

  • The project has demonstrated uneven distribution of biogas between headspace and gas collection device with maximum of 30% difference.
  • Experiments with continuous flow bioreactor showed critical factors affecting the yields of biological hydrogen production during dark fermentation.
  • Approaches were developed to enhance hydrogen yield and shift metabolic pathways.

Lessons learned

  • Gas measurements in both head space and gas collection device are required to ensure representative biogas production determination.
  • Loss of electron carrier from the bioreactor can decrease hydrogen yields.
  • Excess biomass concentration during dark fermentation can result in supersaturation of hydrogen and affect metabolic pathways.

Project finish date

June 2024

Relevant project publications

  1. Cheng, KY; Kaksonen, A; Cord-Ruwisch, R. Bioelectrochemical system for ammonia recovery from wastewater and concomitant production of high purity hydrogen gas. Asia-Pacific Conference on Biotechnology for Waste Conversion (BioWC 2016), Hong Kong, 6-8 December 2016.
  2. Cheng, KY; Cord-Ruwisch, R; Kaksonen, A. Bioelectrochemical ammonia recovery and high-purity hydrogen production from synthetic municipal wastewater. 10th IWA Leading Edge Conference on Water and Waste Water Technologies, Bordeaux, France, 3–6 June 2013.
  3. Beath, AC; Sun Y; Meybodi MA. Integration of concentrated solar thermal energy with biogas production and use. Asia-Pacific Solar Research Conference (APSRC 2021), Sydney, 15-16 December 2021.
  4. Cheng KY; Kaksonen, A; Cord-Ruwisch, R (2022) Bioelectrochemical extraction of ammonium from low-strength wastewater with concomitant generation of high-purity hydrogen. Environmental Technology, 1-12. doi.org/10.1080/09593330.2022.2141663
  5. Song S, Ginige MP, Cheng KY, Qie T, Peacock CS, Kaksonen AH. 2023. Dynamics of gas distribution in batch-scale fermentation experiments: The unpredictive distribution of biogas between headspace and gas collection device. Journal of Cleaner Production 400: 136641.
  6. Kaksonen AH, Cheng KY, Ginige M, Song S, Beath A. 2023. Prospects and pitfalls for biological hydrogen production. The third International Forum on Hydrogen Production Technologies (HyPT-3), held virtually 12-15 September 2023.
  7. Kaksonen AH, Beath A, Song S, Ginige M, Cheng KY, Wylie J, Hossain MI, Hurtado-McCormick V, Chaudry S, Boxall N, Morris C, Ashton J, Nagaraj V. 2023. Bio-based solutions for decarbonisation. Third John Glover Symposium 2023: Decarbonising the WA economy. Perth 6-7 October 2023.
  8. Song S. 2024. New insights into biohydrogen production through dark fermentation: A in-depth investigation with a pure culture. PhD Thesis submitted to the University of Western Australia.

HyResearch record

Hydrogen and NH3 from organics – HyResearch (csiro.au)