Seasonal variation of biogas upgrading coupled with digestate treatment in an outdoors pilot scale algal-bacterial photobioreactor

• DOI: 10.1016/j.biortech.2018.04.117
• Publication Date: 2018-04-30T08:33:31Z
• Authors: David Marín; Esther Posadas; Patricia Cano; Victor Pérez; Saúl Blanco; Raquel Lebrero; Raúl Muñoz
• Keywords: Digestate; Photobioreactor; Biogas

The yearly variations of the quality upgraded biogas and efficiency digestate treatment were evaluated in an outdoors pilot scale high rate algal pond (HRAP) interconnected to external absorption column (AC) via a conical settler. CO2 concentrations ranged from 0.7% August 11.9% December, while complete H2S removal was achieved regardless operational month. CH4 85.2% December 97.9% June, with limited O2 N2 stripping mediated by low recycling liquid/biogas ratio AC. Biomass productivity 0.0 g m−2 d−1 winter 22.5 summer. Finally, microalgae diversity severely reduced throughout year likely due increasing salinity cultivation broth HRAP induced process operation absence effluent.