MDEA脱硫液的表面张力研究

Investigation of the Surface Tension for MDEA Desulfurization Liquid

N-甲基二乙醇胺（MDEA）水溶液的表面张力是硫化氢醇胺吸收工艺的一个重要参数.用德国KUASS K11全自动界面张力仪的铂金板法测定了288.15～348.15K全浓度范围内的MDEA水溶液的表面张力,并用经验公式对实验数据进行了拟合,拟合曲线与实验值吻合良好.在此基础上对MDEA的热力学性质（表面熵,表面焓）进行了进一步分析,结果表明,表面熵在摩尔分数为0.016 5以下时熵变化较快,在0.016 5～0.184 7之间变化不明显,但随着摩尔分数的继续增加表面熵呈下降趋势.表面焓在摩尔分数为0.060 8以下和0.184 7～0.260 6之间变化较快,在0.060 8～0.184 7和0.260 6以上时焙变化趋于缓慢.

The surface tension of N-methyldiethanolamine （MDEA） aqueous solution is an important parameter for the hydrogen sulfide absorption technology by alcohol amine aqueous solutions. The surface tensions of MDEA aqueous solution were measured by using the platinum plate method of German KUASS Kll automatic interfacial tension-meter from 288. 15 to 348. 15K. The empirical formula was used to correlate the experimental data, and the simulation values have a good agreement with the experimental ones. Based on these experiments, the thermodynamic properties of MDEA （surface entropy, surface enthalpy） were further analyzed. The results showed that the change of the surface entropy and enthalpy were related to the mole fraction. When the mole fraction was less than 0. 016 5, the surface entropy changed faster; it didn＇t change obviously while the mole fraction was between 0.016 5 - 0. 184 7, and with the increase of the mole fraction, the surface entropy tended to decline. For the surface enthalpy, it changed faster when the mole fraction was less than0. 060 8 and between 0. 184 7 - 0. 260 6, and the change speed tended to fall when the mole fraction was between 0. 060 8 - 0. 184 7 and more than 0. 260 6.