Simulated Moving Bed Adsorption Research Articles

A simulated moving-bed adsorber for the separation of tricomponents.

A mixture of three components was separated into its components by using a simulated moving-bed adsorber in which columns packed with one kind of resin was arranged so as to alternate with columns packed with another kind of resin. One component adsorbs weakly on both the resins, whereas each of the other two components adsorbs strongly on one (but not both) of the two resins. The first component moves with the flow of the desorbent solution, whereas the others move with the resins in the opposite direction to the liquid flow. The first component, therefore, is obtained continuously in the raffinate stream, while the other two are recovered alternately in the extract stream. The validity of this type of adsorber was examined of a computer simulation and was confirmed by the experimental separation of a starch-glucose-NaCl mixture.

Preparative scale enantioseparation of a chiral epoxide: Comparison of liquid chromatography and simulated moving bed adsorption technology

AbstractThe feasibility of using simulated moving bed technology (SMB) for chiral separation on cellulose triacetate is demonstrated on the preparative scale: 1 kg of a chiral epoxide has been separated. On comparing SMB technology with conventional liquid chromatography it turns out that the main advantage of SMB lies in the significant reduction of mobile phase consumption. The process design for SMB is made theoretically and the predictions are confirmed by our pilot study. © 1993 Wiley‐Liss, Inc.

Continuous Separation of Sugarcane Molasses with a Simulated Moving-Bed Adsorber. Adsorption Equilibria, Kinetics, and Application

Fundamental chromatographic properties are reported that are related to the industrial separation of sugarcane molasses in a simulated moving-bed adsorber. The distribution coefficients of KCL, sucrose, glucose, and fructose on XUS-40166.00 (K[sup +]) cation exchanger were determined by pulse testing to be 0.00, 0.22, 0.45, and 0.50 at infinite dilution at 70 C. The adsorption isotherm of KCl is quadratic; those of the sugars only slightly nonlinear and dependent on KCl concentration. HETP was found to be independent of fluid velocity for KCl in the range of the interstitial velocity of 5 to 35 cm/min, and increasing with v for sucrose. At high fluid velocities the broadening of the sucrose band in a packed bed comes primarily from intraparticle mass transfer, with axial dispersion and film diffusion playing minor roles. The process for separation of sugarcane molasses was demonstrated on a 47 liter, eight-column simulated moving-bed adsorber. A theoretical, staged model of the simulated moving-bed adsorber with one inert totally excluded and three linearly adsorbing components was found to give an excellent representation of the transient and steady-state behavior of the continuous separation of sugarcane molasses.

Theoretic study of backmixing in simulated moving-bed adsorption process with multiple equilibrium stages between ports

A theoretic analysis of the simulated moving-bed process operated as a packed-bed with multiple equilibrium stages between external process ports is undertaken. A model has been proposed that correctly describes the time-averaged movement of individual process streams within the process. Axial mixing is incorporated into the model using the concept of mobile phase backmixing. The number of equilibrium stages between external process ports is shown to be an important parameter when considering design and operation of the simulated moving-bed process as a packed bed.

Optical resolution by simulated moving-bed adsorption technology

The application of the simulated moving bed adsorption (SMBA) technique to optical resolution using eight columns packed with chiral stationary phases was studied. The SMBA system was compared with the conventional batch system, and it was concluded that the former is better from the point of productivity and solvent recovery. In addition, it was shown that an optimum particle size of the chiral phase to attain the maximum productivity exists if a certain upper limit of the pressure drop is assumed.

Simultaneously Continuous Separation of Glucose, Maltose, and Maltotriose Using a Simulated Moving-Bed Adsorber.

Simultaneously Continuous Separation of Glucose, Maltose, and Maltotriose Using a Simulated Moving-Bed Adsorber.

A new process for multicomponent continuous separation by combining multiple liquid chromatography columns.

As a method for making liquid chromatography a continuous operation, a simulated moving-bed adsorber has been applied. This method is applicable only to two-component mixtures. Hence a new process for multi-component separation by combining multiple liquid chromatography columns was proposed. Its applicability was confirmed partly by experiments with a single column in the process and partly by simulation of the separation of dimethyl phthalate, diethyl phthalate, and di-n-butyl phthalate. The results showed that a mixture of more than three components can be separated and refined by use of this process. The values of distribution coefficient and overall mass transfer coefficient for each component required for the simulation were obtained from impulse response experiments, using the same column.

Continuous separation of glycerol and NaCl with linear and unfavorable adsorption isotherms by use of a simulated moving-bed adsorber.

Continuous separation of glycerol and NaCl with linear and unfavorable adsorption isotherms by use of a simulated moving-bed adsorber.

A simplified design method for a simulated moving-bed adsorber.

A simulated moving-bed adsorber is constructed with several adsorption columns, which are usually arranged into four zones to carry out their inherent functions. Some models have been proposed to calculate the concentration profiles of adsorbates in the adsorber, but they are not always useful in designing adsorbers. A simplified method is proposed to determine the length of columns, their arrangement into four zones and the operating conditions of the adsorber, in the case where the adsorption isotherms of two components are linear and independent of each other.

A simulated moving-bed adsorber with three zones for continuous separation of L-phenylalanine and NaCl.

A simulated moving-bed adsorber with three zones for continuous separation of L-phenylalanine and NaCl.

Continuous desalting of proteins with a simulated moving-bed adsorber.

A simulated moving-bed adsorber (SMBA) consisting of only three or four columns packed with gel chromatographic materials was applied for the continuous desalting of bovine serum albumin (BSA) from ammonium sulfate. It was shown experimentally that the solutes could be continuously recovered in different streams at concentrations of over 50% of their feed concentrations. The recovery of BSA was in the range of 70 ∼ 80%, while that of ammonium sulfate was over 95%. Calculation showed that BSA could be recovered at the concentration of over 90% of its concentration in the feed with a recovery of over 98%. The criteria for the flow rates in the SMBA were also shown for good separation.

Continuous separation of α-cyclodextrin and glucose using a simulated moving-bed adsorber

α-Cyclodextrin and glucose were continuously separated by a simulated moving-bed adsorber made up of four or 12 columns packed with the sodium ion form of a cation exchanger. In both cases, the components were successfully separated. The effect of the number of columns constituting the adsorber on the recovery of α-cyclodextrin was examined theoretically. The use of more than eight columns resulted in almost the same recovery.

Continuous separation of glucose-salts mixture with nonlinear and linear adsorption isotherms by using a simulated moving-bed adsorber.

Continuous glucose/NaCl separation was successfully performed by using a simulated moving-bed adsorber packed with ion-retardant resin. Two kinds of mathematical models, i.e. an intermittent moving-bed model and a continuous moving-bed model, were proposed to calculate concentration profiles in the adsorber where the adsorption isotherms of the first component (NaCl) and the second component (glucose) are represented respectively by the Langmuir equation and by a linear equation. The validity of the calculation methods proposed was experimentally confirmed.

The separation of glutathione and glutamic acid using a simulated moving-bed adsorber system

Glutathione (GSH) and glutamic acid (Glu) were continuously separated using a simulated moving-bed adsorber system. In this system, a specially-designed multi-port rotary valve was used to move the adsorbent particles, and its rotation speed and the liquid flow rate in the adsorber were controlled by a personal computer. Under the optimal conditions for the simulated moving-bed adsorber, both the purity and the yield coefficient of GSH in the raffinate stream at a steady state reached around 99%, and the concentration of GSH and the production of GSH for the amount of adsorbent used were greater by as much as ten times and eighteen times than for the conventional batch operation. The adsorption isotherms of GSH and Glu, which were non-linear and concetration-dependent, wre well expressed using several parameters, and also the courses of GSH and Glu concentrations in transient changes to the steady-state condition could be predicted well by the intermittent moving-bed model.

Models for the separation of glucose/fructose mixture using a simulated moving-bed adsorber.

The continuous separation of a glucose/fructose mixture was experimentally performed using a simulated moving-bed adsorber packed with the Ca2+ ion form of Y zeolite. In the adsorber, the continuous and countercurrent contact of the liquid stream with the solid adsorbent is simulated by advancing adsorption columns against the fixed inlets and outlets of liquid streams, without actual movement of the solid adsorbent. Two mathematical models, i.e., an intermittent moving-bed and a continuous moving-bed type, are presented for calculating the concentration profiles of glucose and fructose in the simulated moving-bed adsorber. The validity of the models is experimentally confirmed, and a criterion for good separation in the simulated moving-bed adsorber is presented.