Partial-discard strategy for obtaining high purity products using simulated moving bed chromatography.

Department of Chemical Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, South Korea.
Journal of Chromatography A (Impact Factor: 4.26). 08/2006; 1122(1-2):161-73. DOI: 10.1016/j.chroma.2006.04.040
Source: PubMed

ABSTRACT A new "partial-discard" operation strategy was developed to improve the performance, especially purity, achievable in simulated moving bed (SMB) chromatography. This strategy was applied to the four-zone SMB process with two columns per zone for binary separation within the linear range. The "partial-discard" strategy significantly enhanced the purity or enrichment when the discard time and discard length were controlled. In addition, the "partial-feed with partial-discard" strategy improved remarkably the extract and raffinate purities at an intermediate feed time compared with the "partial-feed" operation. Adjustments of the discard length and discard time played key roles in achieving the desired product purity in SMB chromatographic performance.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The recycling partial-discard (RPD) strategy was developed to improve the performance of simulated moving bed (SMB) chromatography in partial-discard (PD) strategy by a simulation study. In the RPD operation, each discarded product portion of extract and raffinate is recycled as part of the feed. This strategy was applied to a binary mixture with a nonlinear isotherm in a four-zone SMB with two columns per zone. The two additional operating variables, recycle length (RL) and recycle flowrate (RF), were suggested for the RPD strategy in order to determine the time duration and flowrate of the recycle feed. Compared to those of the PD operation, extract and raffinate with higher purities can be produced from the RPD operation. Simultaneously, the losses in the other performance parameters (recovery, productivity, and eluent consumption) stemming from the PD operation could be favorably reduced by controlling the recycle length and recycle ratio in the RPD operation. The two variables, RL and RF, in the RPD operation played key roles in the improvement and trade-off of SMB performance parameters (purity, recovery, productivity, and eluent consumption).
    Industrial & Engineering Chemistry Research 07/2012; 51(29):9835–9849. · 2.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A multiple-frontal analysis (MFA) method, which was based on the data from multiple-frontal experiment, was reported to provide the most reliable adsorption parameters, particularly for the design of continuous chromatographic processes. However, if size-exclusion phenomenon occurs simultaneously with adsorption, the application of the MFA method is impracticable unless the size-exclusion factor is known beforehand. To address this issue, we developed the strategy of estimating empirically both adsorption parameter and size-exclusion factor on the basis of the multiple-frontal experimental data for a linear isotherm system. First, the existing MFA method was modified in such a way that the data related to the adsorption equilibrium of interest could be obtained without having any information on the size-exclusion factor. The result from such a modified MFA method was then applied to a series of repetitive simulations based on the reformed column model. Finally, the result from such simulation works was combined with the result from the modified MFA method, which could eventually allow the calculation of the adsorption parameter. It was confirmed from a case study that the aforementioned strategy was highly effective in estimating empirically both the adsorption parameter and the size-exclusion factor on the basis of the multiple-frontal experimental data.
    Journal of Liquid Chromatography &amp Related Technologies 04/2014; 37(15). · 0.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This work presents a comprehensive insight about simulated moving bed (SMB) technology, from concept to unit operation and process demonstration. A particular relevance is given to SMB nonconventional modes of operation, modeling, and design of SMB-based separations as well as to the construction and operation of SMB units. A conventional separation of a racemic mixture of (S,R)-α-tetralol by means of the FlexSMB-LSRE® unit is addressed to better exemplify a state-of-the-art SMB lab-scale process development and demonstration.
    Chemical Engineering & Technology 01/2012; 35(1). · 1.37 Impact Factor