초록
The anaerobic digestion of lipid-extracted Nannochloropsis at different substrate to inoculum ratios (SIR), biomass concentrations and after thermal hydrolysis pre-treatments exhibited higher CH<SUB>4</SUB> production rates than its non-extracted counterpart. Thermal pretreatment supported a CH<SUB>4</SUB> productivity enhancement of 40% for the non-extracted Nannochloropsis and 15% for the lipid-extracted Nannochloropsis. The higher initial rates of CH<SUB>4</SUB> production for the extracted microalgae, together with this lower extent of enhancement by thermal hydrolysis, suggested that lipid-extraction constituted itself a pretreatment to increase the biochemical CH<SUB>4</SUB> potential of microalgae. From an energy balance viewpoint, the minimum microalgae concentration necessary to achieve an energy-sufficient thermal hydrolysis process depends directly on the CH<SUB>4</SUB> productivity of the pre-treated microalgae.