传统溶剂分离含氮化合物的分子识别与萃取剂优选OA

Nitrogen-containing compounds,which are ubiquitous in coal tar and diesel streams,represent species with both environmental concerns and high-value potential.Conventional hydrodenitrogenation is limited by high energy consumption and the degradation of valuable heterocyclic structures.To address these limitations,this study focused on economically viable and scalable traditional solvent systems for nitrogen removal.Using the COSMO-RS simulation,we conducted systematic solvent pre-screening and mechanistic analysis.Infinite dilution activity coefficients were employed to quantify solubility,selectivity,and a comprehensive performance index,thereby allowing the separation behaviors and driving forces to be elucidated.The results revealed that hydrogen-bonding interactions governed the separation efficiency.Among amide solvents,N,N-dimethylformamide(DMF)showed the best performance for basic nitrogen compounds,whereas N-methyl-2-pyrrolidone(NMP)performed optimally for non-basic species.In acidic media,sulfuric acid(H2SO4)outperformed hydrochloric acid(HCl)for both substrate types.Molecular surface charge distribution analysis indicateed that the key mechanisms involveed directed N-H…O=C hydrogen bonding and an enhanced mass-transfer process facilitated by a protonation-coupled hydrogen-bond network.Based on these insights,practical solvent-selection guidelines were proposed:Solvents with well-defined donor-acceptor sites,strong interaction capability,and the ability to form stable hydrogen-bonding networks should be prioritized.This study provided a quantitative basis for rapid solvent screening and formulation in nitrogen-containing systems and offered a practical pathway toward molecular-structure-preserving separation and valorization of heterocyclic nitrogen compounds.