MDEA/正丁醇/水溶液的CO_(2)平衡溶解度和吸收热实验研究  

Experimental study on CO_(2) equilibrium solubility and absorption heat of MDEA/n-butanol/aqueous solution

作　　者：唐建峰[1,2] 许义飞 桑伟 陈洁 孙培源[1,2] 王铭 TANG Jianfeng;XU Yifei;SANG Wei;CHEN Jie;SUN Peiyuan;WANG Ming(College of Pipeline and Civil Engineering,China University of Petroleum(East China),Qingdao 266580,Shandong,China;Shandong Provincial Key Laboratory of Oil and Gas Storage and Transportation Safety,China University of Petroleum(East China),Qingdao 266580,Shandong,China)

机构地区：[1]中国石油大学(华东)储运与建筑工程学院,山东青岛266580 [2]中国石油大学(华东)山东省油气储运安全省级重点实验室,山东青岛266580

出　　处：《低碳化学与化工》2023年第3期123-129,共7页Low-Carbon Chemistry and Chemical Engineering

摘　　要：在胺/物理溶剂/水相变吸收体系中,由于物理溶剂取代了相变吸收剂中的部分水,导致溶液的物化性质发生改变,从而影响了溶液的热力学性能。采用静态平衡法和绝热量热法对物理溶剂型液液相变吸收剂N-甲基二乙醇胺(MDEA)/正丁醇/水溶液在不同吸收温度和溶液配比下的CO_(2)平衡溶解度和吸收热变化规律进行了分析。结果表明,与CO_(2)的化学溶解度相比,吸收温度的升高对CO_(2)物理溶解度的负面影响更大;溶液富相黏度随着MDEA含量(质量分数,下同)或正丁醇含量的增加而不断增加,导致气液相间的传质阻力不断上升,当溶液中CO_(2)溶解度超过1.0 mol/mol时,溶液中正丁醇含量越高,其平衡溶液度曲线越平缓。溶液的反应热随着吸收温度的升高而增加,当吸收温度超过333.15 K时,在水的作用下MDEA与CO_(2)的反应将向逆反应方向移动;当CO_(2)溶解度低于0.3 mol/mol时,溶液的化学吸收占据主导地位,导致不同正丁醇含量的溶液反应热基本一致;当CO_(2)溶解度超过0.3mol/mol时,物理溶剂溶解CO_(2)的优势得以体现,使得吸收热下降的幅度增大。In the amine/physical solvent/water phase change absorption system,the physicochemical properties of the solution are changed because the physical solvent replaces part of the water in the phase change absorbent,which affects the thermodynamic properties of the solution.The static equilibrium method and adiabatic calorimetry method were used to analyze the CO_(2) equilibrium solubility and absorption heat of the physical solvent liquid-liquid phase change absorbent N-methyldiethanolamine(MDEA)/n-butanol/aqueous solution at different absorption temperatures and solution ratios.The results show that compared with the chemical solubility of CO_(2),the increase of absorption temperature has a greater negative effect on the physical solubility of CO_(2).The rich phase viscosity of the solution increases with the increase of MDEA content(mass fraction,the same below)or n-butanol content,resulting in the increase of mass transfer resistance between gas and liquid phases.When the CO_(2) solubility in the solution exceeds 1.0 mol/mol,the higher the content of n-butanol in the solution,the flatter the equilibrium solubility curve.The reaction heat of the solution increases with the increase of the absorption temperature.When the absorption temperature exceeds 333.15 K,the reaction between MDEA and CO_(2) will move in the reverse direction under the action of water.When the CO_(2) solubility is lower than 0.3 mol/mol,the chemical absorption of the solution dominates,resulting in a consistent reaction heat of the solution at different n-butanol contents.When the CO_(2) solubility exceeds 0.3 mol/mol,the advantage of physical solvent to dissolve CO_(2) is reflected,which increases the decrease of absorption heat.

关 键 词：相变吸收剂 CO_(2)溶解度 吸收热 N-甲基二乙醇胺 正丁醇 

分 类 号：TQ51[化学工程] X511[环境科学与工程—环境工程]