DMAC水溶液乙酸吸附分离过程  

Adsorption separation process of acetic acid in DMAC aqueous solution

作　　者：李海凤[1] 王成习[1] 

机构地区：[1]浙江大学化学工程与生物工程学院,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2016年第9期1725-1729,1745,共6页Journal of Zhejiang University：Engineering Science

摘　　要：采用大孔弱碱性阴离子交换树脂D301G吸附分离N,N-二甲基乙酰胺(DMAC)水溶液中低浓度的乙酸.通过静态实验,研究溶液中DMAC的质量分数对吸附结果的影响,分析D301G树脂对乙酸的吸附热力学和动力学过程.结果表明,DMAC的存在降低了D301G树脂的平衡吸附量,但D301G树脂对于低浓度的乙酸仍具有良好的吸附与再生性能.D301G树脂对乙酸的吸附符合Langmuir等温吸附方程.通过热力学分析得到吸附热力学参数吉布斯自由能变、吸附焓变、吸附熵变均小于0.说明该吸附过程为自发进行、放热、熵减小的过程.对吸附过程采用准一级动力学方程和准二级动力学方程进行拟合,发现准二级动力学方程更适合描述D301G树脂对乙酸的吸附过程.Macroporous weakly basic anion exchange resin D301G was used to separate acetic acid in low concentration of N , N-dimethylacetamide aqueous solution. The influence of DMAC, adsorption thermo-dynamics and kinetics were investigated by static adsorption experiments. Results show that the existence of DMAC can decrease the equilibrium adsorption capacity, but resin D301G still has a good adsorption and regeneration performance for acetic acid in low concentration. The adsorption behavior of acetic acid on resin D301G can be described reasonably well by Langmuir equation. Thermodynamic analysis suggests that Gibbs free energy, adsorption enthalpy and entropy decrease are all below zero, which indicates that the adsorption process is a spontaneously exothermic reaction with entropy decrease. The kinetics data is fitted to pseudo-first-order model and pseudo-second-order model, respectively, which shows that the ad-sorption process of acetic acid on resin D301G can be described well by pseudo-second-order model.

关 键 词：离子交换树脂 DMAC 乙酸 吸附分离 

分 类 号：TQ028.3[化学工程]