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Biogas upgrading from vinasse digesters: a comparison between an anoxic biotrickling filter and an algal‐bacterial photobioreactor
Author(s) -
Lebrero Raquel,
ToledoCervantes Alma,
Muñoz Raúl,
del Nery Valéria,
Foresti Eugenio
Publication year - 2016
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4843
Subject(s) - biogas , photobioreactor , pulp and paper industry , digestate , environmental science , effluent , bioreactor , waste management , anoxic waters , chemistry , anaerobic digestion , biofuel , environmental engineering , environmental chemistry , engineering , methane , organic chemistry
BACKGROUND Biological technologies for biogas upgrading such as anoxic biotrickling filters ( BTF ) and algal–bacterial photobioreactors ( PBR ) constitute a cost‐effective, environmentally friendly alternative to conventional physical–chemical methods. Nonetheless, there is a lack of studies comparing their performance when treating real biogas. RESULTS A H 2 S removal efficiency >98% was consistently recorded in both systems, with elimination capacities up to 26 and 12.4 g S‐ H 2 S m −3 h −1 in the BTF and PBR , respectively, at empty bed residence times ( EBRTs ) of ∼ 30 min. Both bioreactors demonstrated a high robustness towards fluctuations in biogas composition and flowrate, maintaining nearly complete desulfurization despite the variations in sulfur load and EBRT . The BTF also showed an immediate recovery from a 15 days operational shut‐down, and the ability to utilize the nutrients from nitrate‐supplemented digestate during biogas desulfurization. In addition, the PBR supported an average CO 2 removal of 23.0 ± 11.8%, increasing to 62% at higher pH of 8.1, with a carbon fixation rate of 285 mg CO 2 L −1 d −1 . CONCLUSIONS The BTF was confirmed as a robust technology for the desulfurization of real biogas, even when supplemented with effluent from the digester. High H 2 S removal was also achieved in the PBR , the CO 2 fixation capacity of microalgae enhancing biogas purification. © 2015 Society of Chemical Industry