[1S02m] 02. AFOB - Part 1

10:00 AM - 10:25 AM JST(1:00 AM - 1:25 AM UTC)

[1AFOB-01-KL] Microalgae-driven Negative Carbon, C2X pathways, and Carbon Circularity - Current advances and future challenges

○Jo-Shu Chang¹ (1. Tunghai University (Taiwan))

Keywords:

Bio-based chemicals,Biofuels,Biorefinery,Carbon capture and utilization,Circular bioeconomy

Microalgae represent a highly promising yet underutilized biological platform for carbon capture and utilization (CCU), with growing relevance for achieving net-negative emissions in integrated energy and industrial systems. Through photosynthesis, microalgae can fix CO₂ at rates 20-100 times higher than terrestrial plants and directly utilize carbon from diverse sources, including ambient air, industrial flue gas, biogas, and fermentation off-gas. Importantly, microalgal CCU extends beyond carbon sequestration alone, as the resulting biomass provides a renewable feedstock rich in carbohydrates, proteins, lipids, and pigments, enabling the co-production of biofuels, chemicals, materials, and high-value bioproducts that can displace fossil-derived counterparts and enhance carbon retention along the value chain. Large-scale demonstrations, including the world’s first ton-scale microalgal CCU facility using blast furnace flue gas from a steel-making factory and subsequent hectare-level biorefinery pilot plants at National Cheng Kung University, have established the technical feasibility of industrial deployment. More recently, the development of microalgae-bacteria consortia has enabled the simultaneous capture of carbon and the removal of nitrogen and phosphorus from industrial and livestock wastewaters, further strengthening circular bioeconomy linkages and reducing the environmental footprint of wastewater treatment. Nevertheless, the large-scale commercialization of microalgae-based CCU remains constrained by energy-intensive cultivation and harvesting processes, land-use requirements, and comparatively slower CO₂ uptake kinetics relative to physicochemical capture technologies. This presentation discusses system-level strategies to overcome these barriers, including the integration of chemical absorption with biological fixation and the use of sustainable carbon and nutrient sources to enhance CCU efficiency, economic viability, and product value.