Evaluation of marine biomass as a source of methane in batch tests: A lab-scale study

Marine biomass is considered an important feedstock for anaerobic digestion to generate energy; however, its utilization as an energy source is still minimal around the world. In the current study, the biochemical methane potential test was used to evaluate energy recovery from seaweed, brown algae, green algae, and fish viscera as substrates for methane production. Cumulative CH4 yields of 256 ± 28 and 179 ± 35 mL CH4/g VS were observed using green and brown algae, respectively, after 60 days of digestion. The CH4 content of the biogas was approximately 70% for both substrates. Lower CH4 yields of 127 ± 20 and 102 ± 25 mL CH4/g VS were observed using fish viscera and seaweed, respectively. Given that 44 ± 15% of the TCOD was converted to CH4, a longer adaption period or pretreatment of the marine biomass is necessary to fully convert the TCOD to CH4. ► The BMP test was used to evaluate energy recovery from marine biomass. ► Cumulative CH4 yields of 256 ± 28 mL CH4/g VS was observed using green algae. ► Using brown algae cumulative CH4 yields of 179 ± 35 mL CH4/g VS was observed. ► Lower CH4 yields of and 102 ± 25 mL CH4/g VS was observed using seaweed.