Algae-derived N-doped porous carbons with ultrahigh specific surface area for highly selective separation of light hydrocarbons

Light hydrocarbons are important alternative energy sources and raw materials, thus developing efficient adsorbents is of great importance for separating each C1/C2/C3 component in a pressure swing adsorption (PSA) process. Herein, we selected low-cost and ultrafast-growing algae as the precursor and applied the facile one-pot method to prepare N-doped porous carbons. The obtained algae-derived N-doped porous carbons (ANPCs) showed ultrahigh specific surfaces areas of 1437–3177 m² g⁻¹, large pore volumes of 0.637–2.18 cm³ g⁻¹, and rich N-heteroatom content of 1.74–10.37 wt%. Moreover, the ANPC samples exhibited outstanding C₃H₈ (11.5 mmol g⁻¹), C₃H₆ (11.3 mmol g⁻¹), C₂H₆ (6.84 mmol g⁻¹), and C₂H₄ (5.71 mmol g⁻¹) adsorption capacities with excellent IAST separation selectivities of C3/C1 (189), C2/C1 (15.3), and C3/C2 (9.81) at 298 K and 1.0 bar. Impressively, ANPC-1-800 showed the C₂H₆-selective adsorption feature that is much more favorable in C₂H₄/C₂H₆ separation. Furthermore, the detailed evaluation of VSA working parameters, dynamic breakthrough experiment, and adsorption cycle experiment confirmed that the ANPCs are potent and promising adsorbents for practical light hydrocarbon separation.