Under an ARC Linkage Project (LP100100128, 2010-2015), an ARC Discovery Project (DP140100621, 2014-2016) and direct research contracts (2015) with Biogas Energy Pty Ltd (www.biogasenergy.com.au) a synthetic phenazine called neutral red (2-amino-8-dimethylamino-3-methylphenazine) has been shown to enhance methane production from food waste fed methanogenic cultures. In 2015 Biogas Energy granted permission to UNSW Sydney to publish findings from supported research efforts regarding the application of electrochemical amendments to the anaerobic digestion of renewable organic feedstocks. The findings were published in the high impact Royal Society for Chemistry journal Energy and Environmental Science.
Under physiological conditions and above solubility limits neutral red precipitates in a crystalline form that attracts electrons at a mid point potential of +69 mV (SHE) and delivers electrons to the membrane bound heterodisulfide reductase enzyme of methanogenic Archaea at -325 mV. This enhances the ability of these methane producing microbes to generate proton motive force and hence energy for proliferation and methane production. The result is a large increase in cell numbers and methane production independent of the reduced organic feedstock.
Knowledge gaps remain relating to fundamental biochemical and microbiological aspects of the phenomenon and applied aspects relating to anaerobic digestors and landfill scenarios. Whilst the approach has been tested in the field in a submerged coal seam 80 mbgs in the Western Coalfields of NSW, it has not yet been tested in the context of bioreactor or landfill infrastructure.
Biogas Energy Pty Ltd is seeking partnerships to further develop the technology for domestic, medium and industrial scale anaerobic digestion applications.