Synthetic Methodologies and Structural Engineering of Biomass-Derived Adsorbents for CO₂ Capture

Developing sustainable, scalable, low-cost adsorbents constitutes a core prerequisite to realize practically viable CO₂ capture technologies. Biomass-derived porous carbons represent attractive candidate sorbents owing to renewable raw feedstocks, tailorable pore architecture, intrinsic hydrophobic character, and moderate regeneration energy demand. This review adopts a methodology- and engineering-driven perspective to examine rational design principles, scalable fabrication routes, and structural engineering strategies of biomass-derived adsorbents for high-efficiency CO₂ capture. Material-level links between manufacturing pathways, physicochemical features, and resultant CO₂ adsorption performance are critically analyzed, covering a broad suite of carbonization, activation, and surface-modification approaches. Beyond material characteristics, engineering-relevant aspects are addressed, including pelletization of powdered sorbents, reactor configuration, and practical implementation within PSA (pressure swing adsorption), VSA (vacuum swing adsorption), and TSA (temperature swing adsorption) cyclic adsorption workflows for industrial-scale deployment. Key existing bottlenecks are outlined, such as lack of standardized synthesis workflows, insufficient anti-contamination performance, barriers for large-scale manufacturing, and absence of unified performance-assessment benchmarks. Corresponding future research avenues are suggested to promote the translation of lab-scale biomass-derived adsorbent research toward real-world CO₂-capture practice.