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

Abstract

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 technoeconomic and life‐cycle assessment for colocating a 121‐ha algae facility with a 2,680‐ha eucalyptus forest for BECCS. The eucalyptus biomass fuels combined heat and power (CHP) generation 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 that include 1) algal biomass sold for $1,400/t (fishmeal replacement) with a $68/t carbon credit and 2) algal biomass sold for $600/t (soymeal replacement) with a $278/t carbon credit. 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.

Investigating the BECCS resource nexus: delivering sustainable negative emissions

“…In order to obtain the same result while avoiding competition with other uses of agricultural residues, using high productivity-high carbon content biomass such as algae, could be a promising alternative. 48 A second important trade-off exists between water use and land use change: minimising water use for BECCS might result in high land use change, particularly when the availabilities of marginal land and crop residues are constrained. This conclusion builds upon the previous contribution of Heck et al, 5 where this potential compromise was first alluded to.…”

Direct capture and conversion of CO2 from air by growing a cyanobacterial consortium at pH up to 11.2

“…The technical, economical and environmental feasibility of negative emission technologies (NET) (Bui et al, 2018), such as BECCS, are currently under debate (Scott & Geden, 2018;Van Vuuren, Hof, Van Sluisveld, & Riahi, 2017;Xenias & Whitmarsh, 2018). To overcome this problem, several studies have proposed the use of biofuels/bioenergy derived from phototrophic microorganisms (instead of plants) as a means to simultaneously displace fossil fuels and capture carbon dioxide from the atmosphere (Beal, Archibald, Huntley, Greene, & Johnson, 2018;Vadlamani, Pendyala, Viamajala, & Varanasi, 2019;Wijffels & Barbosa, 2010). To overcome this problem, several studies have proposed the use of biofuels/bioenergy derived from phototrophic microorganisms (instead of plants) as a means to simultaneously displace fossil fuels and capture carbon dioxide from the atmosphere (Beal, Archibald, Huntley, Greene, & Johnson, 2018;Vadlamani, Pendyala, Viamajala, & Varanasi, 2019;Wijffels & Barbosa, 2010).…”

“…For example, BECCS would require a large amount of arable land (~990 Mha; Bui et al, 2018), competing with food production (Ingram et al, 2015). To overcome this problem, several studies have proposed the use of biofuels/bioenergy derived from phototrophic microorganisms (instead of plants) as a means to simultaneously displace fossil fuels and capture carbon dioxide from the atmosphere (Beal, Archibald, Huntley, Greene, & Johnson, 2018;Vadlamani, Pendyala, Viamajala, & Varanasi, 2019;Wijffels & Barbosa, 2010).…”

When are negative emissions negative emissions?

“…targets, which refers to greenhouse gases that are physically removed from the atmosphere. Some LCAs 23,24 further conflate these terms by lumping together physical removal and assumed avoidance of greenhouse gases while other LCAs simply use the term negative emissions to refer to avoided emissions without any removal of atmospheric greenhouse gases at all. 23,26,27 The full list of LCAs in the review that conflate the term negative emissions with avoided emissions is available in the supplemental information.…”