Optimal design of a simulated-moving-bed chromatographic process for high-purity separation of acetoin from 2,3-butanediol in a continuous mode.

For the high-purity production of acetoin or 2,3-butanediol (BD) from related fermentation processes, it is essential to accomplish a detailed separation between acetoin and BD in an economical mode. To address this issue, we aimed to develop a highly-efficient simulated-moving-bed (SMB) process for the continuous-mode separation of acetoin from BD with high purity and small loss. As a first step for this task, the adsorption and mass-transfer parameters of acetoin and BD on a proven adsorbent were estimated while assuming that BD isomers (meso-BD and DL-BD) would be identical in adsorption and mass-transfer behaviors.

Relationship between desorbent usage and the recovery of a target product in three-zone simulated moving bed processes designed under the conditions of positive and negative flow-rate-ratios of liquid to solid phases.

For a simulated moving bed (SMB) chromatographic process, it has been common knowledge that as desorbent usage increases, the level of separation capability (i.e., the purity and recovery of a target product) continues to improve and then eventually reaches almost a constant level.

Continuous-mode separation of fucose and 2,3-butanediol using a three-zone simulated moving bed process and its performance improvement by using partial extract-collection, partial extract-recycle, and partial desorbent-port closing.

If a multi-component monosugar mixture including fucose was used as the substrates for the Klebsiella oxytoca fermentation, it could offer the following two benefits simultaneously; (i) the removal of all monosugars other than fucose, and (ii) the acquisition of 2,3-butanediol (BD). To utilize such two benefits in favor of the economical efficiency of the fucose production process, it is essential to accomplish a high-purity separation between fucose and BD on the basis of a highly-economical mode. To address this issue, we aimed to develop a simulated moving bed (SMB) process for continuous-mode separation of fucose and BD with high purities.

Optimization of production rate, productivity, and product concentration for a simulated moving bed process aimed atfucose separation using standing-wave-design and genetic algorithm.

The effectiveness of a simulated moving bed (SMB) technology in the continuous separation of fucose from a multi-component monosugar mixture, which stemmed from defatted microalgae, has recently been identified. To guarantee high economical efficiency of such fucose-production method, the comprehensive optimization of the relevant fucose-separation SMB process needs to be accomplished such that its production rate (Prate) and/or productivity (Prod) can be maximized while meeting the requirements on fucose product concentration (C) and pressure drop (ΔP). To resolve this issue, the SMB optimization program based on standing-wave-design method and genetic algorithm was prepared and then applied to the fucose-separation SMB optimization.

Standing wave design and optimization of a simulated moving bed chromatography for separation of xylobiose and xylose under the constraints on product concentration and pressure drop.

The feasibility of a simulated moving bed (SMB) technology for the continuous separation of high-purity xylobiose (X2) from the output of a β-xylosidase X1→X2 reaction has recently been confirmed. To ensure high economical efficiency of the X2 production method based on the use of xylose (X1) as a starting material, it is essential to accomplish the comprehensive optimization of the X2-separation SMB process in such a way that its X2 productivity can be maximized while maintaining the X2 product concentration from the SMB as high as possible in consideration of a subsequent lyophilization step. To address this issue, a suitable SMB optimization tool for the aforementioned task was prepared based on standing wave design theory.

Design of simulated moving bed for separation of fumaric acid with a little fronting phenomenon.

The production of fumaric acid through a biotechnological pathway has grown in importance because of its potential value in related industries. This has sparked an interest in developing an economically-efficient process for separation of fumaric acid (product of interest) from acetic acid (by-product). This study aimed to develop a simulated moving bed (SMB) chromatographic process for such separation in a systematic way.

Improvement of the performances of a tandem simulated moving bed chromatography by controlling the yield level of a key product of the first simulated moving bed unit.

One of the trustworthy processes for ternary separation is a tandem simulated moving bed (SMB) process, which consists of two subordinate four-zone SMB units (Ring I and Ring II). To take full advantage of a tandem SMB as a means of recovering all three products with high purities and high economical efficiency, it is important to understand how the separation condition in Ring II is affected by that in Ring I, and further to reflect such point in the stage of designing a tandem SMB. In regard to such issue, it was clarified in this study that the Ring I factors affecting the Ring II condition could be represented by the yield level of a key product of Ring I (Y).

Highly efficient recovery of xylobiose from xylooligosaccharides using a simulated moving bed method.

Xylobiose (X2), which is currently available from xylooligosaccharides (XOS), has been reported to have outstanding prebiotic function and to be highly suitable for application in food industries. This has sparked an interest in the economical production of X2 of high purity (> 99%) in food and prebiotic industries. To address such issue, we developed a highly-efficient chromatographic method for the recovery of X2 from XOS with high purity and high recovery.

Effect of adsorbent particle size on the relative merits of a non-triangular and a triangular separation region in the optimal design of a three-zone simulated moving bed chromatography for binary separation with linear isotherms.

The design approaches for a three-zone simulated moving bed (SMB) chromatography with linear isotherms can be classified into two categories, depending on whether the SMB design is based on a classical region (i.e., triangular region of the triangle theory) in the first quadrant (m2, m3) plane or on a non-triangular separation region in the third quadrant (m2, m3) plane.

Continuous recovery of valine in a model mixture of amino acids and salt from Corynebacterium bacteria fermentation using a simulated moving bed chromatography.

The economical efficiency of valine production in related industries is largely affected by the performance of a valine separation process, in which valine is to be separated from leucine, alanine, and ammonium sulfate. Such separation is currently handled by a batch-mode hybrid process based on ion-exchange and crystallization schemes. To make a substantial improvement in the economical efficiency of an industrial valine production, such a batch-mode process based on two different separation schemes needs to be converted into a continuous-mode separation process based on a single separation scheme.

Simulated moving bed separation of agarose-hydrolyzate components for biofuel production from marine biomass.

The economically-efficient separation of galactose, levulinic acid (LA), and 5-hydroxymethylfurfural (5-HMF) in acid hydrolyzate of agarose has been a key issue in the area of biofuel production from marine biomass. To address this issue, an optimal simulated moving bed (SMB) process for continuous separation of the three agarose-hydrolyzate components with high purities, high yields, and high throughput was developed in this study. As a first step for this task, the adsorption isotherm and mass-transfer parameters of each component on the qualified adsorbent were determined through a series of multiple frontal experiments.

Optimal design and experimental validation of a simulated moving bed chromatography for continuous recovery of formic acid in a model mixture of three organic acids from Actinobacillus bacteria fermentation.

The economically-efficient separation of formic acid from acetic acid and succinic acid has been a key issue in the production of formic acid with the Actinobacillus bacteria fermentation. To address this issue, an optimal three-zone simulated moving bed (SMB) chromatography for continuous separation of formic acid from acetic acid and succinic acid was developed in this study. As a first step for this task, the adsorption isotherm and mass-transfer parameters of each organic acid on the qualified adsorbent (Amberchrom-CG300C) were determined through a series of multiple frontal experiments.

Enhanced performance of a three-zone simulated moving bed chromatography for separation of succinic acid and lactic acid by simultaneous use of port-location rearrangement and partial-feeding.

The performance of a three-zone simulated moving bed (SMB) chromatographic process for separation of succinic acid and lactic acid has been improved to a certain extent in previous researches by applying either a partial-feeding (PF) or a port-location rearrangement (PR) to its operation. To make a further improvement, the strategy of applying both PF and PR simultaneously to the three-zone SMB operation was proposed in this study. The results from both equilibrium-theory analysis and detailed simulation proved that the proposed strategy, which was called PF-PR in this article, had the benefit of a synergy between the individual merits of PF and PR in the three-zone SMB performance.

Comparison of the relative merits of port-location rearrangement and partial-feeding as the strategy for improving the performances of a three-zone simulated moving chromatography for separation of succinic acid and lactic acid.

The three-zone simulated moving bed (SMB) chromatographic process for separation of succinic acid and lactic acid, which has been developed previously, was based on a classical port-location arrangement (desorbent→extract→feed→raffinate) and a classical feeding mode (full-feeding). To improve the performance of the three-zone SMB process, it is worth utilizing the strategy of either a port-location rearrangement (desorbent→feed→raffinate→extract) or a partial-feeding. To investigate which of the two strategies is more effective, the three-zone SMBs based on the port-location rearrangement (PR) and the partial-feeding (PF) were optimized each under equal conditions and then the two strategies were compared in terms of product purities or throughput.

Experimental evaluation of the effect of a modified port-location mode on the performance of a three-zone simulated moving-bed process for the separation of valine and isoleucine.

The removal of isoleucine from valine has been a key issue in the stage of valine crystallization, which is the final step in the valine production process in industry. To address this issue, a three-zone simulated moving-bed (SMB) process for the separation of valine and isoleucine has been developed previously. However, the previous process, which was based on a classical port-location mode, had some limitations in throughput and valine product concentration.

Improving performance of a tandem simulated moving bed process for sugar separation by making a difference in the adsorbents and the column lengths of the two subordinate simulated moving bed units.

A tandem simulated moving bed (SMB) process for removal of sulfuric acid and acetic acid from sugars has been developed previously. This process consisted of two four-zone SMB units (Ring I and Ring II), in which the same adsorbent (Dowex99 resin) and the same column length were used. To improve the performance of such a tandem SMB process for sugar separation, it is worth adopting the strategy of making a difference between the column lengths of Ring I and Ring II.

Development of a non-triangular separation region for improving the performance of a three-zone simulated moving bed chromatography for binary separation with linear isotherms.

For a three-zone simulated moving bed (SMB) chromatography with linear isotherms, the feasible set of operating parameters for complete separation is known to exist within a triangular region of the triangle theory that is formed in the operating parameter plane spanned by the flow-rate-ratios in the separation zones (II and III), which are commonly denoted as m(2) and m(3). Such an operating region for complete separation region, however, has been established only in the first quadrant (m(2), m(3)) plane, where m(2)>0 and m(3)>0, until now. In this study, a new complete-separation region was developed in the third quadrant (m(2), m(3)) plane, where m(2)<0 and m(3)<0, regarding a three-zone SMB process for the first time.

Strategy of rearranging the port locations in a three-zone simulated moving bed chromatography for binary separation with linear isotherms.

A three-zone simulated moving bed (SMB) chromatographic process for binary separation, which has been developed previously, was reported to have four ports that are located in the order of desorbent, extract, feed, and raffinate. To make a substantial improvement in the performance of such a three-zone SMB process, the strategy of rearranging the port locations was proposed in this study within a linear isotherm region. The core of the proposed strategy is to transfer the location of the extract port from its classical position (i.

Improving performance of a five-zone simulated moving bed chromatography for ternary separation by simultaneous use of partial-feeding and partial-closing of the product port in charge of collecting the intermediate-affinity solute molecules.

The performance of a five-zone simulated moving bed (SMB) chromatographic process for ternary separation has been improved to a certain extent in previous researches by applying either a partial-feeding (PF) or a partial-closing of the extract-2 port (PCE(2)) to its operation. To make a further improvement, the strategy of applying both PF and PCE(2) simultaneously to the five-zone SMB operation was proposed in this study. The results from both equilibrium-theory analysis and detailed simulation proved that the proposed strategy, which was called PF-PCE(2) in this article, had the benefit of a synergy between the individual merits of PF and PCE(2) in the five-zone SMB performance.

Development of a four-zone carousel process packed with metal ion-imprinted polymer for continuous separation of copper ions from manganese ions, cobalt ions, and the constituent metal ions of the buffer solution used as eluent.

A three-zone carousel process, in which Cu(II)-imprinted polymer (Cu-MIP) and a buffer solution were employed as adsorbent and eluent respectively, has been developed previously for continuous separation of Cu²⁺ (product) from Mn²⁺ and Co²⁺ (impurities). Although this process was reported to be successful in the aforementioned separation task, the way of using a buffer solution as eluent made it inevitable that the product stream included the buffer-related metal ions (i.e.

Determination of chromatographic separation parameters of tryptophan enantiomers on a Chirosil-SCA chiral stationary phase by using the inverse method based on the initial guesses estimated from elution by characteristic point method.

An effective chiral stationary phase (CSP) for enantioseparation of amino acids was established previously by bonding (18-crown-6)-2, 3, 11, 12-tetracarboxylic acid to silica gel. This CSP has recently been commercialized under the name of Chirosil-SCA. As a first step for developing a Chirosil-SCA simulated moving bed chromatographic process for separation of tryptophan enantiomers, the adsorption isotherm and mass-transfer parameters of each tryptophan enantiomer on the Chirosil-SCA CSP were determined in this study while using only water as a mobile phase.

Continuous separation of copper ions from a mixture of heavy metal ions using a three-zone carousel process packed with metal ion-imprinted polymer.

In this study, a three-zone carousel process based on a proper molecular imprinted polymer (MIP) resin was developed for continuous separation of Cu(2+) from Mn(2+) and Co(2+). For this task, the Cu (II)-imprinted polymer (Cu-MIP) resin was synthesized first and used to pack the chromatographic columns of a three-zone carousel process. Prior to the experiment of the carousel process based on the Cu-MIP resin (MIP-carousel process), a series of single-column experiments were performed to estimate the intrinsic parameters of the three heavy metal ions and to find out the appropriate conditions of regeneration and re-equilibration.

Partial port-closing strategy for obtaining high throughput or high purities in a four-zone simulated moving bed chromatography for binary separation.

The "partial port-closing" operation strategy for a four-zone simulated moving bed (SMB) chromatographic process for binary separation was developed to improve the SMB performance. This strategy included the partial extract-closing (PEC) and the partial raffinate-closing (PRC) operations. In case of the PEC operation, the extract port is made to be closed during the first-half stage of a switching period.

Phenomena of insulin peak fronting in size exclusion chromatography and strategies to reduce fronting.

Insulin peak fronting in size exclusion chromatography (SEC) results in more than 10% yield loss in the production of insulin. The goal of this study is to understand the mechanisms of peak fronting and to develop strategies to reduce fronting and increase insulin yield. Chromatography experiments ruled out pressure surge, viscous fingering, and adsorption as the cause for peak fronting.

Theoretical analysis of the effects of reversible dimerization in size exclusion chromatography.

Reversible dimer formation in size exclusion chromatography (SEC) can cause peak splitting, merging, tailing, and fronting. Such behavior can be predicted by the association rate and the dissociation rate relative to the convection rate. Slow association and dissociation result in separated monomer and dimer peaks.