摘要
基于COSMO-RS,以碳酸二甲酯(DMC)选择度为考察指标,研究了离子液体在分离甲醇-DMC体系中的应用;通过与实验数据对比,验证了COSMO-RS预测离子液体分离能力的准确性。通过对26种阴离子与27种阳离子组成的702种离子液体进行筛选以及对表面电荷密度分布进行分析,探讨了阴阳离子对共沸物分离效果的影响,并筛选出5种对DMC选择度较高的阴离子,选择度顺序为[PF_6]>[Tf_2N]>[BTI]>[B(CN)_4]>[BF_4];阳离子对DMC选择度影响较小,但碳链或支链增加能提高离子液体对DMC的选择度。根据筛选结果,离子液体[hmim][PF_6]在甲醇-DMC共沸物分离中具有一定的应用前景。
Based on the COSMO-RS theory, ionic liquids were used as extractants for the separation of the methanol and dimethylcarbonate（DMC） system. It was confirmed that COSMO-RS could accurately predict the separation capacity of the ionic liquids by the contrast between the predicted data and the experimental data. The influences of cations and anions on the separation of the azeotrope of methanol and DMC were investigated based on 702 ionic liquids（consisted of 26 kinds of anions and 27 kinds of cations） and the surface charge density distribution, in which five kinds of anions showed the excellent selectivity to DMC, and the order was ranked as follows [ PF6 ] 〉 [ Tf2N ] 〉 [ BTI ] 〉 [ B（CN）4 ] 〉 [ BF4 ]. The influences of the cations on the selectivity were less than those of the anions. The selectivity to DMC increased with the increase of both the length of alkyl chain and the number of side chains. According to the screening results, [ hmim ] [ PF6 ] showed its potential in the separation process of the methanol-DMC azeotrope.
出处
《石油化工》
CAS
CSCD
北大核心
2016年第12期1499-1505,共7页
Petrochemical Technology
