Application of carbon biological sequestration technology in CCUS: Potential and optimization strategies for inorganic carbon absorption by plant root and CO2 carriers by biogas slurry

Abstract

Atmospheric CO₂ concentrations have surged to historically high levels, driving extreme weather events, biodiversity loss, and threats to food security. Carbon Capture, Utilization, and Storage (CCUS) is recognized as a critical pathway to mitigate these impacts, yet conventional physicochemical methods incur high energy demands and operational costs. Biological carbon sequestration—harnessing autotrophic organisms to convert inorganic CO₂ into organic biomass—offers a low-energy, clean alternative, but its large-scale deployment is hindered by limited fixation efficiency and technological maturity. This review synthesizes advances in CCUS with a focus on plant-based inorganic carbon uptake and novel CO₂ carriers for agricultural applications. We dissect the molecular and physiological mechanisms underpinning HCO₃⁻ absorption by plant roots and evaluate biogas slurry—a nutrient-rich byproduct of anaerobic digestion—as a dual-function carrier and fertilizer. Strategies to enhance slurry CO₂ loading, including pH elevation via biomass ash and biochar amendments, are discussed alongside their impacts on crop growth, soil health, and carbon retention. Lifecycle assessments demonstrate that biogas slurry–based sequestration reduces energy requirements by up to 65% and greenhouse-gas intensity by 67% compared to monoethanolamine capture. We outline tailored deployment scenarios across tropical, temperate, arid, and cold agroecosystems and propose research priorities—multisite field trials, optimization of carrier composites, comprehensive LCAs, and interdisciplinary collaboration—to drive the transition toward low-energy, high-value carbon biological sequestration in global agriculture.