Publication: Integrating Algae with Bioenergy Carbon Capture and Storage (ABECCS) Increases Sustainability

Bioenergy Carbon Capture and Storage (BECCS) has been proposed to reduce atmospheric CO₂ concentrations, but concerns remain about competition for arable land and freshwater. The synergistic integration of algae production, which does not require arable land or freshwater, with BECCS (called “ABECCS”) can reduce CO₂ emissions without competing with agriculture. This study presents a techno-economic and life-cycle assessment for co-locating a 121-ha algae facility with a 2,680-ha eucalyptus forest for BECCS. The eucalyptus biomass fuels combined heat and power generation (CHP) with subsequent amine based carbon capture and storage (CCS). A portion of the captured CO₂ is used for growing algae and the remainder is sequestered. Biomass combustion supplies CO₂, heat, and electricity, thus increasing the range of sites suitable for algae cultivation. Economic, energetic, and environmental impacts are considered. The system yields as much protein as soybeans while generating 61.5 TJ of electricity and sequestering 29,600 t of CO₂ per year. More energy is generated than consumed and the freshwater footprint is roughly equal to that for soybeans. Financial break-even is achieved for product value combinations ranging from 1) algal biomass sold for $1,780/t without a carbon credit to 2) algal biomass sold for $100/t with a carbon credit of $396/t. Sensitivity analysis shows significant reductions to the cost of carbon sequestration are possible. The ABECCS system represents a unique technology for negative emissions without reducing protein production or increasing water demand, and should therefore be included in the suite of technologies being considered to address global sustainability.

Beal CB, Archibald I, Huntley ME, Greene CH, Johnson ZI (2018) Integrating Algae with Bioenergy Carbon Capture and Storage (ABECCS) Increases Sustainability. Earth’s Future. DOI: 10.1002/2017EF000704