Hybrid biogas upgrading in a two-stage thermophilic reactor

摘要: Abstract The aim of this study is to propose a hybrid biogas upgrading configuration composed two-stage thermophilic reactors. Hydrogen directly injected in the first stage reactor. output gas from reactor (in-situ upgrade) subsequently transferred second upflow (ex-situ upgrade), which enriched hydrogenotrophic culture responsible for hydrogenation carbon dioxide methane. overall objective work was perform an initial methane enrichment in-situ reactor, avoiding deterioration process due elevated pH levels, and subsequently, complete ex-situ chamber. content reached on average 87% corresponding value 91%, with maximum 95%. A remarkable accumulation volatile fatty acids observed (in-situ) after 8 days continuous hydrogen injection reaching concentration 5.6 g/L. Nevertheless, adaptation period, system managed recover decreased 2.5 g/L. No drop recorded during period characterised by increased mainly consumption endogenous methanogens. effect microbial community both reactors analysed 16S rRNA gene amplicon sequencing. results demonstrated increment relative abundance methanogens homoacetogens while chamber simpler dominated