Biogas from algae via anaerobic digestion

Abstract

Anaerobic digestion is a promising application of algal biomass for producing bioenergy while allowing recovery of inorganic nutrients (nitrogen and phosphorus) for reuse. Anaerobic digestion of algae requires pretreatment of the biomass and/or codigestion with carbon-rich cosubstrates, as discussed in this chapter. In the absence of pretreatment, the methane yield is reduced apparently because of the recalcitrance of the algal cell wall. Encouraging pretreatments and codigestion approaches have been developed but require validation at pilot-scale. Improved estimates of the energy demands of the various pretreatments are required to decide if a certain pretreatment is energetically worthwhile undertaking.