Grant: Applied Research and Development Grants - Level 2

The enterprise EBI Énergie (EBI) converts biogas collected from landfill cells into renewable natural gas (RNG). The biogas has high H2S content and the enterprise must remove it in two phases. The first phase is a biological desulphurization process which decrease the H2S concentration from an average of 1500 ppm to around 30 ppmv. In a second chemical adsorption phase, EBI polishes the biogas to reach the quality which must have to be injected in a gas pipeline. EBI started up the operation of biological desulphurization process two years ago due to an unexpected increase of H2S in raw biogas from historical 400 ppmv to up to 1500 ppmv. The last concentration stayed stable and EBI was obligated to install a pretreatment unit to decrease operating costs for biogas upgrading. The biological desulphurization process presents high removal efficiency if it is well operated. The bioprocess is almost completely automated, except for microbiological parameters. The enterprise would like to develop biological indicators, such as metabolomic factors, which let to know the good state of microbial population. This is very important for EBI because the enterprise was obligated to stop the bioprocess due to accumulation of elementary sulfur and biomass in the packed bed of adsorption tower which clogged the bed. The stop of this bioprocess represents high expenses for EBI, because must flare the untreated biogas during the changing of packing material. The results of this project will let to determine the wright and wrong regions for operating parameters linked with main indicators. Measures to correct deviations of indicators will be tested at laboratory scale. This will be helpful to develop protocols to operate the bioprocess under robust and stable operating mode.