烷烃中少量芳烃的模拟移动床吸附及模拟

在实验研究烷烃中少量芳烃的模拟移动床吸附动态过程及其条件的基础上 ,用模拟移动床吸附模型进行了模型化拟合计算 ,传质采用线性推动力模型 ,得出轴向扩散系数和总传质系数。结果表明 :模拟移动床吸附动态模型的计算值与实验值相符 ;用吸附动态模型计算得出的轴向扩散系数与由关联式计算出的值相一致 ,且与流速成正比 ;总传质系数随着进料流量的增加而增大 ;区域 和区域 中 ,总传质系数随着温度和质量分数的升高而逐渐增大。区域 和区域 中 ,总传质系数随着温度的升高和质量分数的降低而逐渐减小。在低流量下 ,区域 和区域 中的总传质系数远比区域 和区域 中的总传质系数小。以上实验与计算结果为在直链烷基苯的生产过程中 ,降低循环烷烃中芳构化物的含量 ,实现延长脱氢催化剂的寿命提供了技术基础。     

脱除烷烃中少量芳烃的模拟移动床吸附过程研究

研究了烷烃中少量芳烃的模拟移动床吸附动态过程,并在此基础上,用模拟移动床稳态和暂态吸附模型进行了拟合计算,传质采用线性推动力模型。结果表明:在文中的实验条件下,模拟移动床吸附分离过程可以达到将烷烃中的少量芳烃分离的目的。无论是稳态模型还是暂态模型的模拟计算结果都与实验值相符,且2个模型分别得到的轴向扩散系数和总传质系数相接近。在文中的实验条件下,总传质系数随切换时间的延长而减小。以上实验与计算结果为在直链烷基苯的生产过程中,降低循环烷烃中芳构化物的质量分数,实现延长脱氢催化剂的寿命提供了技术基础。     

固定床吸附烷烃中芳烃的模拟

本文在实验研究烷烃中少量芳烃的固定床吸附动态过程的基础上,进行模型化计算,分别用线性推动力和孔扩散两种固定床吸附模型,拟合得出总传质系数,液膜传质系数和孔扩散系数,两种模型的拟合计算结果表明：在本文的实验条件范围内,传质推动力可用线性推动力表示。总传质阻力由液膜传质阻力和颗粒相传质阻力的共同作用而形成,它随着温度,浓度和流量的降低而增加,孔扩散系数与流量无关。     

吸附法脱除烷烃中少量芳烃工业可行性分析

在实验研究烷烃中少量芳烃的吸附动态过程的基础上,确定该吸附净化过程的吸附一再生条件,探讨该过程实现的可行性,得到如下结论：从技术性能和技术经济这两个指标出发,对脱除循环烷烃中的少量芳烃的吸附分离过程,用固定床吸附过程来实现比用模拟移动床吸附过程来实现更具可行性,吸附法脱除循环烷烃中的少量芳烃具有设备投资少,能耗低的特点,有可能成为一种替代现行脱除少量芳烃的工艺方法,这些结果为在直链烷基苯的生产过程中,降低循环烷烃中芳构化物的含量,实现延长脱氢催化剂的寿命,提高烷基苯的产量提供了技术基础。     

模拟移动床吸附分离间二甲苯

采用多柱串联连续吸附流程,利用模拟移动床从混合二甲苯中分离间二甲苯。讨论了进料组成、吸附比、置换比、脱附比、温度、压力等因素对产品纯度的影响,产品质量分数达９９．５％以上     

模拟移动床吸附分离技术的研究与开发

本文简述了模拟移动床吸附分离技术研究和开发过程中的吸附剂、解吸剂体系评价、小试、中试及工业放大试验各阶段所需进行的工作和方法。     

移动床与固定床活性炭吸附处理有机废水的技术经济分析

本文着重从活性炭吸附机理上阐述了移动床和固定床吸附处理有机废水的区别,并结合国内外有关生产实践进行了分析比较,证明在技术和经济上,移动床吸附优于固定床。     

模拟移动床技术进展

综述了近年来模拟移动床技术多方面的进展。模拟移动床吸附分离已由石油化工领域逐步扩展到精细化工尤其是制药行业。模拟移动床模型和设计方法的研究更趋深入。模拟移动床反应器将反应和分离结合在一起,可以大大提高过程的效率,虽未进入实用但潜力很大。     

模拟移动床吸附分离技术及其在分离果糖中的应用

一、前言 模拟移动床吸附分离技术是一种高效、先进的分离技术,它是由液相色谱技术发展而来的,它不仅最初已成功地应用于石油化学工业,即分离正构烷烃、对二甲苯等,而且用于从果葡糖中分离高纯果糖。目前,正在不断开发新的应用领域。 本文介绍它的原理及特点,以用于制取高纯果糖为例,说明由试验室开发至工业化所需进行的工作。     

模拟移动床吸附分离对甲乙苯工艺

为了实现C9芳烃中对甲乙苯资源的高效利用,以X型分子筛为吸附剂,以混合甲乙苯为原料,采用液相模拟移动床吸附工艺分离对甲乙苯(p-MEB)与邻甲乙苯(o-MEB)、间甲乙苯(m-MEB)。在操作温度为75℃、操作压力为0. 25 MPa的条件下,在液相模拟移动床吸附分离装置上考察了操作条件对p-MEB吸附分离过程的影响规律,获得优化的p-MEB吸附分离工艺条件为:模拟移动床区域分布采用6-3-4-3模式,切换时间900 s,分配比1. 1,循环比3. 5,脱附剂比9. 3。对于pMEB质量分数为20. 78%的C₉芳烃,优化分离工艺条件下得到的p-MEB质量分数为94. 52%,回收率达到90. 86%。     

模拟移动床吸附模型的计算应用

采用模拟移动床实现分子筛脱蜡过程是烷基苯生产中的一个重要环节。用模拟移动床动态吸附模型对分子筛脱蜡进行了模拟计算,探讨随时间改变流量的措施对提高分子筛脱蜡过程效率的影响。计算结果表明:进料量、脱附剂流量均随时间周期性地先慢后快变化的操作方式,可提高产量、减少脱附剂用量、节省能耗,同时正构烷烃的纯度及收率都能符合技术指标要求。这一结果为分子筛脱蜡过程的优化提供了更新的理论根据。     

Separation of multicomponent aromatic/aliphatic mixtures by simulated moving bed adsorption: Modeling and experiments

Simulated moving bed (SMB) adsorption has potential for efficient separation of many valuable chemical mixtures, but considerably less attention has been devoted to multicomponent feeds relative to binary mixtures. We take a rigorous experimental and modeling approach to study multicomponent separation of aromatics and aliphatics with a mesoporous silica adsorbent, which is relevant in many petrochemical applications such as separation of reformate and distillate streams. Our approach involves refining multicomponent adsorption, mass transfer, and SMB process parameters based upon detailed experimental inputs, with progressive addition of components. We develop a robust model that quantitatively predicts the influence of key operating parameters such as stream flow rates, desorbent/feed ratio, and switch time on the separation results and concentration profiles. The model is validated as a function of feed complexity by SMB experiments and column concentration profile measurements in a 16-column mini-plant. Furthermore, conditions for clear separation of each mixture are developed.     

The simulated moving-bed reactor for production of bisphenol A

Bisphenol A was produced from acetone and phenol over an ion-exchange resin catalyst at 50–90°C. Phenol was used as solvent. The reaction proceeded under the excess phenol condition. The reaction rate was proportional to the acetone concentration in the initial period of the reaction. After the acetone conversion exceeded approximately 50%, the reaction rate became lower than expected by the first-order reaction rate. This was ascribed to water adsorption onto the resin. Batch adsorption and breakthrough experiments showed that water was adsorbed approximately seven times stronger than acetone and that bisphenol A was not adsorbed. Using the reaction rate equation for bisphenol A production, the adsorption isotherms and overall mass transfer coefficients of the components, the numerical simulation of the 3-zone-type simulated moving-bed reactor was carried out. High resin flow rate was required in order to remove water out of the reaction zone, and a high liquid flow rate was also required to desorb water from the resin in the recovery zone. As far as the flow rates were set appropriately, water was successfully removed to prevent the catalyst deactivation and the long-term stable production of BPA was allowed.     

A three-zone simulated moving-bed for separation of immunoglobulin Y

Separation of immunoglobulin Y (IgY) from hen eggs is an interesting topic for investigating antibody purification. Understanding of IgY separation by chromatography is necessary to prepare antibody. IgY preparation in SMB was simulated by Aspen chromatography and was experimented by assembling a 3-zone simulated moving bed (SMB). With change of stream flow rates, the SMB performance was studied. Simulation of IgY batch HPLC chromatography was also done and confirmed by HPLC experiments. Based on these, good operating conditions of SMB chromatography were determined. Three-zone SMB equipment was set up by connecting three C₁₈-HPLC columns, four HPLC pumps, and six multiposition valves. Batch chromatography of IgY was conducted to determine the isotherms of IgY and contaminating impurity. The outlet streams of SMB, raffinate and extract were sampled and analyzed by analytical HPLC system. The adsorption isotherms of IgY and impurity were determined as H _IgY =0.1 and H _impure =1.1. The highest experimental purity of IgY from SMB was obtained as 98% for the operating parameters of Q _feed =0.2mL/min, Q _desorbent =0.31 mL/min, Q _extract =0.2 mL/min, Q _raffinate =0.3 mL/min, and switching time=8.47 min.     

绝热固定床反应器甲醇脱水合成二甲醚的实验和模型研究

One-dimensional heterogeneous plug flow model was employed to model an adiabatic fixed-bed reactor for the catalytic dehydration of methanol to dimethyl ether. Longitudinal temperature and conversion profiles predicted by this model were compared to those experimentally measured in a bench scale reactor. The reactor was packed with 1.5 mm γ-Al2O3 pellets as dehydration catalyst and operated in a temperature range of 543-603 K at an atmospheric pressure. Also, the effects of weight hourly space velocity (WHSV) and temperature on methanol conversion were investigated. According to the results, the maximum conversion is obtained at 603.15 K with WHSV of 72.87 h－1.     

Fixed-bed adsorption with nonplug flow: Perturbation solution for constant pattern behavior

Adsorption of a dilute solute from a fluid in nonplug flow through a fixed bed is investigated via a perturbation approach. The continuity equation for fixed-bed adsorption with axial dispersion is solved for the constant pattern concentration profile with the axial velocity characterized by a general axisymmetric function and the system having no resistances to external or intraparticle mass transfer. The isotherm is slightly favorable (i.e., concave downward) in order to justify the assumption that axial gradients of concentration are independent of the radial coordinate in the bed, as in the classical problem of Taylor diffusion. A series expansion of a general isotherm is used to treat adsorption equilibrium. The solution reveals the formation of a radial gradient of fluid-phase concentration and breakthrough behavior at the bed outlet dependent on the nonlinearity of the isotherm and the magnitude of the nonplug-flow-velocity profile. The results can be used to predict the breadth of the breakthrough wave of many chromatographic-type processes for packed beds and slightly favorable isotherms.     

半连续式密实移动床离子交换装置吸附K+特性

在一套半连续式密实移动床离子交换装置上,以001×7强酸型阳离子交换树脂作为吸附剂,研究了钾离子的吸附特性。结果显示,密实移动床离子交换柱全柱的钾离子吸附率能够达到99.71％及以上,排放树脂的吸附饱和度达90.76％;同一套装置,在进料条件和进出料控制要求相同的情况下,采用半连续式密实移动床操作的吸附时间为固定床操作的3/8。研究结果为密实移动床的操作和结构优化提供了参考依据,并表明该装置在离子交换领域具有广阔的应用前景。     

应用模拟移动床分离技术提高企业效益

模拟移动床分离技术具有分离专一性强、洗脱剂消耗量小、可连续生产、自动化程度高等优点.这些优点为工业生产带来了巨大的经济效益和操作便利性,比如,缩短分离流程,降低分离工艺的劳动强度和生产成本、增强对有效成份提取的专一性,提高产品收率和品质、改善生产环境,实现清洁生产、从废物中提取高附加值产品等.     

二甲苯模拟移动床分离过程建模与仿真

模拟移动床（SMB）是混合二甲苯分离的重要技术。模拟移动床区域回流比是决定产品质量的关键参数。在真实移动床（TMB）建模方法基础上,结合实际工况数据,建立了模拟移动床吸附分离过程机理模型,并通过分析区域回流比对产品质量的影响,得到不同产品质量要求以及进料品质的情况下区域回流比的操作区间。仿真结果表明,TMB建模方法能较好地描述模拟移动床实际工况。基于机理模型对操作区间的分析结果可以为模拟移动床分离过程的工艺设计和操作提供指导意见。