【作者】 周倩；

【导师】 袁俊生；

【作者基本信息】 河北工业大学 ， 化学工程， 2011， 硕士

【摘要】 离子交换法由于具有良好的选择性和较高的产品回收率,在海水提钾领域已得到广泛应用。随着离子交换设备的不断发展与更新,连续离子交换技术开始应用于海水提钾工艺中。计算机技术的迅猛发展使连续离子交换分离技术进行模拟研究成为可能。由于数学模型的设计和优化不受实验条件的限制,因此更有利于分离过程复杂机理的研究。连续离子交换法海水提钾过程模拟研究是以单柱吸附和洗脱过程的模拟为基础进行的,因此本文分别对单柱吸附和洗脱过程进行模拟研究,考察不同操作参数和因素对实验的影响,为连续离子交换法海水提钾工艺的模拟研究提供理论支持与参考。通过查阅文献选取数学模型和模拟所需的相关参数,在此基础上利用COMSOL仿真模拟软件对单柱钾离子吸附和洗脱过程分别进行模拟。将模拟结果与实验结果相对照,可见平衡扩散模型的模拟效果要优于理想模型。在单柱吸附模拟过程中,选定进料浓度、柱长、柱径和离子交换等温线方程的基础上,随着孔隙率的减小,穿透曲线的穿透时间基本保持不变,保留时间不断增大;而随着传质系数的增大,穿透曲线的穿透时间不断减小,保留时间基本不变;不同流速对穿透曲线的影响较为复杂,随着进料流速的增大,穿透时间不断减小,保留时间也不断减小。单柱洗脱模拟过程与吸附类似,但所得结果有不同。孔隙率的变化对模拟结果的影响不大,但使流出曲线发生平移的总趋势还是存在的,不影响其穿透时间;而随着传质系数的增大,穿透时间减小的速率不断减小。更多还原

【Abstract】 The ion exchange method has been widely used in the field of extracting potassium from seawater, owning to the good selectivity and high product recovery. With the development of the ion exchange device, the technology of continuous ion exchange has applied to the process of extracting potassium from seawater. The rapid development of computer technology has made the simulation of continuous ion exchange possible. Design and optimization of mathematical models without restriction of experimental conditions, therefore, are propitious to the study of the complex mechanism of separation. Based on the simulation of batch adsorption and elution process, simulation of extraction potassium process from seawater by continuous ion exchange was researched. In this paper, the simulations of batch adsorption and elution process were studied, while the effects of different operating parameters and factors were investigated. The above research will provide theoretical support and reference for the simulation of extraction potassium process from seawater by continuous ion exchange.The mathematical models and simulation parameters were selected by referring to the literature. Base on the above, the simulations of batch adsorption and elution process were carried out with COMSOL software. Contrasting the simulation results with experiment data, it can been shown that the equilibrium diffusion model is better than the ideal model.When the feed concentration, length and diameter of column, and ion-exchange isotherm equation are selected, the process of batch adsorption was simulated through the mathematical model. It can be seen with the porosity decreases the penetration time of the breakthrough curve remain unchanged and retention time increasing. With the increasing of mass transfer coefficients, the through time of the curve gradually decreased and retention time basically unchanged. This paper also study the effect of different velocity on breakthrough curve, the results found the influence is very complicated. It was as follow with the increasing of incoming velocity, the through time and retention time also will decrease.The simulation of elution process is similar to the adsorption process, but the results are different. With the change in porosity, the results of simulation have little influence. The trend of making the elution curve translation still exists, but the penetration time was not been influenced. With the increasing of mass transfer coefficients, the rate of the penetrate time continuously decreased.更多还原