2,4-/2,6-二氨基甲苯在D151树脂上的吸附分离

从10种树脂中筛选出D151树脂对2,4-二氨基甲苯和2,6-二氨基甲苯的吸附分离及其热力学性质进行了研究。 测定了吸附等温线，Freundlich模型对实验的拟合度大于Langmuir模型，其相关系数大于0.99。 热力学研究结果表明，在293～313 K条件下，初始质量浓度为60～80 g/L时，2,4-二氨基甲苯的吸附焓变为-4.3490～-5.7558 kJ/mol，自由能变为-0.2911～-1.0346 kJ/mol,吸附熵变为-12.965～-16.150 J/(mol·K);而2,6-二氨基甲苯的吸附焓变为-2.9645～-3.6054 kJ/mol，自由能变为-0.1610～-0.6384 kJ/mol，吸附熵变为-7.939～-11.005 J/(mol·K)。 进一步研究了D151树脂对二氨基甲苯的动态吸附分离，可以将2,6-二氨基甲苯含量从20%提高至99.93%，将2,4-二氨基甲苯含量从80%提高至99.42%。

Adsorption Separation of 2,4-/2,6-Diaminotoluene on D151 Resin

The adsorption separation and thermodynamic behavior of 2,4-diaminotoluene and 2,6-diaminotoluene on macropore acrylic acid weak acid cation exchange resin(D151 resin), which was selected from ten resins, were investigated. The adsorption isotherms of 2,4-diaminotoluene and 2,6-diaminotoluene were measured. The result showed that the adsorption isotherm curves of 2,4-diaminotoluene and 2,6-diaminotoluene on D151 resin fitted Freundlich adsorption isotherm better than Langmuir with the correlation coefficient larger than 0.99. The study of thermodynamics showed that when the initial concentration of 2,4-diaminotoluene were 60～80 g/L within 293～313 K, the adsorption ΔH was -4.3490～-5.7558 kJ/mol, ΔG was -0.2911～-1.0346 kJ/mol, ΔS was -12.965～-16.150 J/(mol·K); and when the initial concentration of 2,6-diaminotoluene were 60～80 g/L within 293～313 K, adsorption ΔH was -2.9645～-3.6054 kJ/mol, ΔG was -0.1610～-0.6384 kJ/mol, and ΔS was -7.939～-11.005 J/(mol·K). The results show that the concentration of 2,6-diaminotoluene can be enriched from 20% to 99.93%, and 2,4-diaminotoluene can be increased from 80% to 99.42% with the dynamic adsorption separation.