BCS - New and improved approach to algae based carbon capture and utilisation

Microalgae (and cyanobacteria) are a promising source of third-generation biomass, which does not compete with agricultural land for food production. Known for their high solar-to-biomass efficiencies, microalgae can be coupled with industrial processes to capture and utilise point-source CO2 emissions to feed a multitude of industries, ranging from high-value food supplements, animal feed, bio-fertiliser or other biorefinery feedstocks. Despite this, large-scale commercial algae cultivation is mostly limited to a small number of high-value products, due to the high costs of conventional photobioreactor designs. A major technical barrier is the intermittent availability of sunlight (or spare electricity) versus the need for continuous CO2 capture from industrial emitters.

To address this challenge, we present a new two-stage approach to algae-based carbon capture and utilisation, which separates CO2 capture from algae growth. Our approach facilitates carbon transport and distribution, allows the use of alternative, more efficient photobioreactor configurations, and enables temporary storage of carbon to balance out fluctuations in CO2 production and algae growth. Decoupling CO2 capture from algae growth, and its simultaneous oxygen production, opens up new applications such as CO2 removal from flammable gases, such as biogas.

Our initial analysis suggests that algae-based CCU would be most suitable for small-to-medium size CO2 emitters, without access to national carbon capture infrastructure, to produce additional value-streams to complement existing operations.