间歇萃取精馏制备高纯甲醇模拟与实验研究

针对工业甲醇制备高纯甲醇的间歇萃取精馏过程,建立了准稳态模型,采用Newton迭代法进行求解。模拟分析了影响高纯甲醇收率的溶剂流率、溶剂加入位置、回流比等因素,并通过实验验证了模型的准确性和可靠性。在实验与模拟计算的基础上,确定了工业甲醇制备高纯甲醇的最佳工艺条件:总理论板数35,萃取剂二甲基亚砜在第10块理论板加入,萃取剂与原料甲醇的体积比0.3,前馏分段回流比8,产品段回流比5,此时,高纯甲醇单程收率可达60%。

间歇精馏塔启动过程的流程模拟及混杂性分析

间歇精馏塔启动过程的流程模拟是通过一个动态混杂系统模型来描述的.通过分析模型中的混杂性问题,对非连续性特性进行了分类:即与启动过程状态转换有关的模型结构的不连续性;与物理过程有关的塔板动力学方程的切换.并针对动态模型所涉及的变量初始值问题,给出了不同类型变量的初值选取方法.最后通过基于gPROMS计算平台的仿真结果和实验结果的比较,验证了模型求解的有效性.

间歇精馏塔启动过程的模型化

Modeling of batch distillation has been mostly based on equilibrium model in previous studies.It leads to a large-scale differential algebraic equations (DAEs) system.Due to its dynamic nature,initialization of the system has been a problem.Batch distillation columns are frequently started up with different initial reboiler charges.A model to express startup behavior of batch columns starting from an empty cold state is proposed to handle this issue.Each tray will be described from a non-equilibrium phase in which only mass and energy transfer are taking place to an equilibrium phase in which the vapor-liquid equilibrium is reached.The switching point between these two phases is decided by the relationship of bubble-point temperature at the operating pressure.The liquid holdup of each tray is related to the geometry of the trays.The model is verified through experiment on a pilot batch plant with a bubble-cap tray column to separate a methanol-water mixture.

旋转填料床间歇精馏不稳态开工过程

为了深入了解三角形螺旋填料旋转床间歇精馏不稳态开工过程的影响因素及规律,以乙醇-水为实验物系进行实验和模型研究。改变料液浓度、再沸器加热功率和转速的开工实验结果表明,旋转填料床中强大的离心力和高效填料的协同作用使得间歇精馏不稳态开工过程得到极大强化、开工时间很短(30min左右),节能;在最佳转速下开工可使馏出液浓度最大,馏出液浓度随料液浓度和再沸器加热功率的增加而增大。旋转填料床间歇精馏过程在最佳转速和较大的再沸器加热功率下开工,效果最好;以平衡级理论为基础建立的数学模型能较好地描述该过程的不稳态开工规律,模拟值与实验值吻合良好,平均相对误差在2%以内。旋转填料床是强化间歇精馏过程的有效途径。