Theory-guided preparation of pore size tunable porous carbon for efficient adsorption and separation of the light hydrocarbons

Abstract

The efficient adsorption and separation of light hydrocarbons is considered to be the vital processes in petrochemicals. Therefore, it is important to design and develop efficient adsorbents. Herein, we investigated the detailed mechanistic effects of the pore size of porous carbon on the adsorption and separation performance of three light hydrocarbons based on GCMC simulations. The optimum pore size range for their adsorption and separation was determined. Accordingly, bamboo fibres-based porous carbons (BPCs) with tunable pore size distribution were prepared using bamboo fibres mixed with different ratios of KOH. The results display that C3H8 (0.7–1.6 nm) exhibits the wider optimal pore size range for adsorption compared to CH4 (0.7–0.8 nm) and C2H4 (0.7–1.2 nm). Meanwhile, the selectivity of C3H8/CH4 (C3H8/C2H4) depends primarily on the 1.0–1.6 nm (1.2–1.6 nm) pore size. Furthermore, BPCs with these optimal pore sizes exhibited excellent adsorption performance for CH4 (2.07 mmol/g), C2H4 (6.29 mmol/g) and C3H8 (12.23 mmol/g). Among them, BPC-4 possessed the greatest selective separation for C3H8/CH4 (11.1) and C3H8/C2H4 (2.3). This study achieved effective adsorption separation of light hydrocarbons, which would further guide the design direction regarding the pore size of light hydrocarbon adsorbents and provide new ideas for preparation of porous carbon materials.