Efficient nicotine separation from tobacco extract using a cellulose-based high-surface-area adsorbent

Efficient nicotine separation technology not only facilitates developing reduced-harm tobacco products but also enables converting nicotine from a "health hazard" to a "high-value chemical". Herein, a simple and green dissolution–regeneration process was used to convert microcrystalline cellulose (MCC) into high-performance regenerated cellulose (RC), enabling efficient nicotine separation from tobacco extract. Structural characterization confirmed the crystalline transition from cellulose I to cellulose II and a 21.20 % reduction in crystallinity. Meanwhile, the specific surface area increased dramatically to 223.00 m²/g, yielding a porous structure with highly exposed hydroxyl groups. RC’s adsorption capacity (30.80 mg/g) was 26.78-fold that of MCC (1.15 mg/g), primarily due to the synergistic effects of increased surface area and crystalline form transition, with the former contributing more significantly (3.77-fold vs. 1.85-fold). Adsorption followed pseudo-second-order kinetics and fitted the Langmuir model, achieving equilibrium within 30 min with a maximum capacity of 34.31 mg/g. Thermodynamic analysis revealed the process to be spontaneous and exothermic. RC’s adsorption capacity decreased with increasing water content, attributed to competitive adsorption by water molecules. At 29.38 % water content, 75.71 % of the adsorption capacity was lost, but solvent regeneration restored 95.39 % of it. Mechanistic studies indicated that hydrogen bonding was dominant, with pyridinic nitrogen as the preferred binding site. Column separation with gradient elution achieved a 98.48 % nicotine recovery, with nicotine content in the separated product exceeding 97.52 %, and performance remained at 95.45 % after five cycles. This study presents a novel green adsorbent for efficient nicotine separation and offers insights into the development of cellulose-based materials for purifying natural products.