Seaweed Valorization through Anaerobic Digestion

Abstract: 
  • Anaerobic Digestion is an exothermal four-step breakdown of a wide range of biomass(carbs, protein, fat) into C1/C2molecules, reversing photosynthesis (=a mechanical cow)
  • Methanogenesis, the last of the four steps, requiresmcractivity only found inArchae, and releasesmethane as value product into the gas phase, lowering the thermodynamic cost of separation
  • AD is rate limited byArchaeagrowth rates (doubling times) to 20d HRT
  • Seaweed is largely an inconvenient, high-ash, high-salt substrate with challenging logistics andmoderate conversion performance as feed, and hence as AD substrate, while competing withabundant terrestrial biomass that is now left unused to decompose, with easier to accessibility
  • Various LCA models have shown irrecoverable CI scores (+120-+150 g CO2eq/ MJ)
  • Key value drivers for CNG are ecosystem services, i.e. methane and pollution avoidance or carbonsequestration, resulting in renewable fuel production (i.e. LCFS, REDD2), and not merely thecommodity revenue
  • Price is a function of amount, form, location, use, time and environmental attributes
  • Conversion rates of 60-80% leave biomass digestate as burden and boon
Author(s): 
Michael R. Schuppenhauer
Attachment: 
PDF icon Seaweed Valorization through Anaerobic Digestion.pdf
Article Source: 
BSE
Category: 
Ecological Services
Seaweed composition