In-situ biogas upgrading in thermophilic granular UASB reactor: key factors affecting the hydrogen mass transfer rate.
Biological biogas upgrading coupling CO2with external H2to form biomethane opens new avenues for sustainable biofuel production. For developing this technology, efficient H2to liquid transfer is fundamental. This study proposes an innovative setup for in-situ biogas upgrading converting the CO2in the biogas into CH4, via hydrogenotrophic methanogenesis. The setup consisted of a granular reactor connected to a separate chamber, where H2was injected. Different packing materials (rashig rings and alumina ceramic sponge) were tested to increase gas-liquid mass transfer. This aspect was optimized by liquid and gas recirculation and chamber configuration. It was shown that by distributing H2through a metallic diffuser followed by ceramic sponge in a separate chamber, having a volume of 25% of the reactor, and by applying a mild gas recirculation, CO2content in the biogas dropped from 42 to 10% and the final biogas was upgraded from 58 to 82% CH4content.
Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
Ilaria
I
Bassani
Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark. Electronic address: panak@env.dtu.dk.
Panagiotis G
PG
Kougias
Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
Irini
I
Angelidaki
D056804:Biofuels; D019149:Bioreactors; D006859:Hydrogen / Q000737:chemistry; D008697:Methane / Q000737:chemistry
D056804:Biofuels; D006859:Hydrogen; D008697:Methane
Anaerobic digestion; Gas-liquid mass transfer rate; Granules; Hydrogen; In-situ biogas upgrading; UASB