A Non-linear Non-ideal Model of Simulated Moving Bed Chromatography for Chiral Separations

A non-linear non-ideal model, taking into account non-linear competitive isotherms, axial dispersion, film mass transfer, intraparticle diffusion, and port periodic switching, was developed to simulate the dynamics of simulated moving bed chromatography (SMBC). The model equations were solved by a new efficient numerical technique of orthogonal collocation on finite elements with periodical movement of concentration vector. The simulated SMBC performance is in accordance with the experimental results reported in the literature for separation of l,1'-bi-2-naphthol enantiomers using SMBC. This model is useful for design, operation, optimization and scale-up of non-linear SMBC for chiral separations with significant non-ideal effects, especially for high solute concentration and small intraparticle diffusion coefficient or large chiral stationary phase particle.

Mathematical modeling of salt-gradient ion-exchange simulated moving bed chromatography for protein separations

The salt-gradient operation mode used in ion-exchange simulated moving bed chromatography (SMBC) can improve the efficiency of protein separations. A detailed model that takes into account any kind of adsorption/ion-exchange equilibrium, salt gradient, size exclusion, mass transfer resistance, and port periodic switching mechanism, was developed to simulate the complex dynamics. The model predictions were verified by the experimental data on upward and downward gradients for protein separations reported in the literature. All design and operating parameters (number, configuration, length and diameter of columns, particle size, switching period, flow rates of feed, raffinate, desorbent and extract, protein concentrations in feed, different salt concentrations in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale-up of salt-gradient ion-exchange SMBC for protein separations.

Separation of phosphatidylcholine from soybean phospholipids by simulated moving bed

A simulated moving bed (SMB), equipped with eight silica-gel columns, was used to separate phosphatidylcholine (PC) from soybean phospholipids. The effects of flow rate in Sections 2 (Q2) and 3 (Q3), switching time, feed flow rate and feed concentration on the operating performance parameters: purity, recovery, productivity and desorbent consumption were studied. Operating conditions leading to more than 90% purity in both outlet streams have been identified, together with those achieving optimal performance. Regions leading to complete separation are observed and explained theoretically. As the mass-transfer effect was not considered, the triangle theory only gives initial guesses for the optimal operating conditions.

Effect of Temperature Variation on the Separation of Sesamin and Sesamolin by Simulated Moving Bed

In this work, sesamin and sesamolin is separated and purified by SMB （simulated moving bed） chromatography. Purity of sesamin and sesamolin can reach 99.2% and 99.9 %, and they can be recovered by 99.9% and 99.4%, respectively. Concentrations of the extract and raffinate was monitored and periodical change of the concentration was observed on experiment. Effects of non-linear adsorption, dead volume, and temperature on the separation are reviewed by the triangle theory to explain the periodical change of concentration. It is found that dead volume has little effect, and temperature fluctuation significantly affects thc separation by SMB. The temperature seriously affects the robust operation of SMB due to the change of Henry＇s constant, which will change the selectivity and restrain the productivity. Although the productivity in this study is only 0.0416 g/L-hr, the cost of the stationary phase used in this study is much lower than that of packed in analytical column. By using this stationary phase, the authors are still able to separate the mixture of sesamin and sesmolin. This will economically attract attention for the application of SMB to purify bioactive compounds on developing botanical drugs.

Numerical Simulation of Asynchronous Simulated Moving Bed Chromatography

Asynchronous simulated moving bed chromatography (ASMBC), known also as the 'VARICOL' process, is more efficient and flexible than the well-known and traditional simulated moving bed chromatography (SMBC). A detailed model of ASMBC, taking account of non-linear competitive isotherms, mass transfer parameters, and complex port switching schedule parameters, was developed to simulate the complex dynamics of ASMBC.The simulated performance is in close agreement with the experimental data of chiral separation reported in the literature. The simulation results show that ASMBC can achieve the performance similar to SMBC with fewer columns and can achieve better performance than SMBC with the same total column number. All design and operation parameters can be chosen correctly by numerical simulation. This detailed ASMBC model and the numerical technique are useful for design, operation, optimization and scale-up of ASMBC.

Purification of L-Lysine in Simulated Moving Bed and Fixed-Bed Chromatography

L-Lysine was produced by a microbial process utilizing a Corynebacterium glutamicum （ATCC 21799） strain. L-Lysine was purified from the cultivated medium by fixed-bed and simulated moving bed （SMB） chromatography. The separation conditions including pH, eluent concentration and Lys+ and Lys2+ adsorption isotherms were studied in batch adsorption. The column capacity, eluent flow rate and eluent concentration have been studied in fixed-bed chromatography. Maximum purification rate of lysine was obtained as 0.066 （g/（g·h）） （per gram resin and per hour） at an eluent flow rate of 10 （mL/min） in fixed-bed chromatography. The results obtained from SMB were 0.11 （g/（g·h）） for L-lysine purification rate and 96% for L-lysine recovery.

Multiobjective Optimization of Simulated Moving Bed by Tissue P System

The binaphthol enantiomers separation process using simulation moving bed technology is simulated with the true moving bed approach （TMB）. In order to systematically optimize the process with multiple productive objectives, this article develops a variant of tissue P system （TPS）. Inspired by general tissue P systems, the special TPS has a tissue-like structure with several membranes. The key rules of each membrane are the communication rule and mutation rule. These characteristics contribute to the diversity of the population, the conquest of the multimodal of objective function, and the convergence of algorithm. The results of comparison with a popular algorithm——the non-dominated sorting genetic algorithm 2（NSGA-2） illustrate that the new algorithm has satisfactory performance. Using the algorithm, this study maximizes synchronously several conflicting objectives, purities of different products, and productivity.

Simulated moving bed separation of tocopherol homologues:simulation and experiments

Chromatograms of tocopherol homologues were obtained by a column of analytical size (inner diameter (ID) 0.46 cm cm×10 cm) packed with silica gel. Adsorption isotherms and film mass-transfer coefficient were estimated from the chroma-tograms by using a general rate model, which considers axial dispersion, external mass-transfer and intraparticle diffusion. Based on the obtained isotherms and mass-transfer coefficient, the separation process of tocopherol homologues on simulated moving bed (SMB) was simulated using the same model. According to the simulated results, a mixture of α-, γ-, δ-tocopherols and other impurities was separated on an SMB equipment. The SMB equipment was composed of 8 columns of ID 2 cm×10 cm, with 2 columns in each section. The solid phase was silica gel, and the mobile phase was n-hexane/2-propanol (99/1 by volume). γ-and δ-tocopherols of purity greater than 98% were obtained with recovery greater than 98%. The effects of operating conditions (flow rates and switching time) on the performance of SMB were studied by both simulation and experiments. It was found that all the simulation results were quite close to the experimental results. We conclude that process development and optimization of operating conditions of SMB by simulation are feasible.

Continuous size fractionation of magnetic nanoparticles by using simulated moving bed chromatography

The size fractionation of magnetic nanoparticles is a technical problem,which until today can only be solved with great effort.Nevertheless,there is an important demand for nanoparticles with sharp size distributions,for example for medical technology or sensor technology.Using magnetic chromatography,we show a promising method for fractionation of magnetic nanoparticles with respect to their size and/or magnetic properties.This was achieved by passing magnetic nanoparticles through a packed bed of fine steel spheres with which they interact magnetically because single domain ferro-/ferrimagnetic nanoparticles show a spontaneous magnetization.Since the strength of this interaction is related to particle size,the principle is suitable for size fractionation.This concept was transferred into a continuous process in this work using a so-called simulated moving bed chromatography.Applying a suspension of magnetic nanoparticles within a size range from 20 to 120 nm,the process showed a separation sharpness of up to 0.52 with recovery rates of 100%.The continuous feed stream of magnetic nanoparticles could be fractionated with a space-time-yield of up to 5 mg/(L∙min).Due to the easy scalability of continuous chromatography,the process is a promising approach for the efficient fractionation of industrially relevant amounts of magnetic nanoparticles.

顺序式模拟移动床色谱高效纯化低聚异麦芽糖应用研究

[目的]提高低聚糖行业的生产效率。[方法]以50型低聚异麦芽糖浆为原料,利用顺式模拟移动床色谱分离技术对其纯化。通过制备色谱单柱试验筛选出钾离子型树脂为合适的分离介质;根据物料平衡原理和顺序式模拟移动床基本原理近似确定分离工艺的初始操作参数,并对分离条件进行优化。[结果]最佳技术参数为:料液折光率60%、柱温65℃、进样量455 mL、进水量682 mL、进样流量37.4 mL/min、进水流量29.6 mL/min以及总循环流量364 mL/h,在此条件下低聚异麦芽糖出口折光为20.40%,纯度达到90.20%,收率达到85.50%。[结论]自主研制的顺序式模拟移动床色谱分离设备可用于高效纯化低聚异麦芽糖。

分子筛吸附剂对不同类型柴油吸附分离性能的研究

采用离子交换法制备分子筛吸附剂,分析发现分子筛吸附剂的孔结构以晶内微孔为主,并含有晶间介孔,具有结晶度高、晶粒分布均匀、弱酸和强酸协同作用的特点。以不同类型柴油为吸附原料和轻型解吸剂(沸点低于柴油),利用模拟移动床分离装置,考察分子筛吸附剂对不同类型柴油的吸附分离性能。结果显示:在吸附温度为120℃、压力为1.2 MPa、吸附区回流比为0.5~1.5、精制区回流比为0.2~1.5、解吸区回流比为2.0~6.0、隔离区回流比-2~0的条件下,分子筛吸附剂在不同类型柴油吸附-脱附体系下运行稳定,芳烃产品中芳烃纯度>95%,非芳烃产品中非芳烃纯度>95%;不同类型柴油中硫氮含量、馏程轻重和芳烃含量对吸附分离效果没有影响,不同类型柴油中芳烃含量越高,解吸剂与柴油体积比越高,在模拟工业应用条件下,分子筛吸附剂稳定运行时间超过600 d,所制得的分子筛吸附剂具有芳烃选择性高、吸附容量大、运行稳定性高等特点。

吸附剂对多环芳烃吸附分离技术的研究

采用专用模板剂制备多环芳烃吸附剂,通过X射线衍射仪(XRD)、全自动比表面分析测试仪(BET)、程序升温化学吸附分析仪(NH_(3)-TPD)、吡啶吸附红外光谱仪(Py-IR)、扫描电镜和透射电镜测试仪(SEM/TEM)等表征方法对是否添加模板剂的吸附剂进行表征分析,并以模拟油品为原料,分别在固定床和模拟移动床吸附分离装置上,考察吸附剂的多环芳烃分离性能。结果表明,与未添加模板剂的吸附剂相比,添加模板剂的多环芳烃吸附剂平均孔径增加43.3%,微孔比表面积降低72.2%,微孔孔容降低87.5%,弱酸量提高31.2%,强酸量提高60%,多环芳烃/非芳烃相对分离度提高52.7%,多环芳烃解吸时间缩短41.4%,甲基萘饱和吸附容量提高14.6%。专用模板剂制备的多环芳烃吸附剂在模拟移动床装置上稳定运行30 d后,非芳烃产品的非芳烃质量分数>95%,多环芳烃产品的多环芳烃质量分数>95%。

模拟移动床色谱分离技术研究进展

模拟移动床色谱(Simulated moving bed chromatography,SMBC)是一种新型分离手段,具有分离效果好、投资成本少以及适合连续性大规模生产等特点,近些年来备受关注,研究热度居高不下,在食品、化工和制药等行业均有广泛应用。SMBC由模拟移动床技术与色谱分离技术相结合产生,通过回顾色谱分离技术的起源,介绍模拟移动床色谱分离技术的原理及应用领域,列举模拟移动床色谱在高效分离淀粉糖、低聚糖、糖醇及有机酸等混合物的实际应用场景,为该技术的工业应用提供参考。

模拟移动床色谱技术及其应用

详细地介绍了一种现代化分离技术模拟移动床色谱技术的发展历史及其工作原理,同时介绍了模拟移动床色谱在石油化工、糖醇分离、手性化合物及其他方面的主要应用。

模拟移动床色谱分离替考拉宁条件研究

探讨了用模拟移动床色谱分离提纯替考拉宁的可行性 ,且优化出最佳分离条件为 ts=1 0min,υF=0 .0 8m L/min,υp=1 .5 m L/min,υD=0 .8m L/min,CF=8mg/m L。

生产银杏黄酮的模拟移动床色谱工艺

Separation of Ginkgo flavonoids using simulated moving bed chromatography to replace the batch chromatography is discussed.The product of higher purity is obtained,and in this process,the yield of product increased and cost decreased.Furthermore,this process is very clean.

银杏内酯B的纯化

报道了具有生产规模的银杏内酯B(GB)纯化工艺。该工艺包括萃取、模拟移动床、结晶3个步骤。其核心是用模拟移动床色谱对银杏内酯B进行规模化精细分离。所得产品纯度w(GB)≥90%,收率≥70%,生产能力20g/h。生产1g银杏内酯B净消耗乙酸乙酯29L,乙醇50mL,甲醇40mL。产物用高效液相色谱、液质联用及核磁共振做了鉴定。

顺序式模拟移动色谱纯化木糖醇母液

以木糖醇母液为原料,采用顺序式模拟移动色谱技术纯化木糖醇母液。在制备色谱研究的基础上,研究顺序式模拟移动床(SSMB)技术纯化木糖醇母液的最佳工艺参数。结果表明最佳工艺参数为:进料浓度60%,进料量为546.00 g/h,进水量为819.00 g/h,循环量382.2 m L。在此条件下木糖醇出口浓度为41.2%,纯度达到94.8%,收率达到90.6%,较木糖醇母液纯度提高31.12%,本研究为木糖醇母液产业化利用奠定了实践基础。

模拟移动床技术分离缬氨酸和丙氨酸

研究了线性条件下模拟移动床分离缬氨酸和丙氨酸的行为,掌握了模拟移动床的基本运行规律,实现了2种中性氨基酸的分离,分离效果远好于普通的分离方法,得到了较高纯度的缬氨酸(98.6%)和丙氨酸(82.9%)产品,提高了生产效率。

模拟移动床色谱法分离纯化链甾醇

以羊毛脂中提取的链甾醇为原料,采用模拟移动床色谱法(SMBC)进行了分离纯化。以C18为固定相,甲醇为洗脱液,采用四区SMBC系统,每区有两根色谱柱(150 mm×10 mm×10μm),经过两次SMBC分离,得到高纯度链甾醇产品。以纯度、生产率和溶剂消耗量为指标,确定链甾醇在SMBC中的最佳分离条件为:切换时间6.4 min,四区流量分别为9.97,7.53,8.53和4.97 mL/min,进料流量1.00 mL/min(第一次SMBC分离);切换时间6.0 min,四区流量分别为9.95,7.98,8.53和6.62 mL/min,进料流量0.55 mL/min(第二次SMBC分离)。结果表明,以90.1%含量的链甾醇粗品为原料,在优化实验条件下,先除去吸附能力比链甾醇强的杂质,再除去吸附能力比链甾醇弱的杂质,得到高纯度(≥98.9%)的链甾醇产品,回收率为93.8%。