Yoshiaki Kawajiri

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In this paper, efficient optimization techniques are used to solve multi-objective optimization problems arising from Simulated Moving Bed (SMB) processes. SMBs are widely used in many industrial separations of chemical products and they are very challenging from the optimization point of view. With the help of interactive multi-objective optimization,(More)
Simulated Moving Bed (SMB) was developed as a realization of continuous countercurrent operation of chromatographic separation. An SMB unit consists of several columns of the same length connected in series, where feed and desorbent are supplied and extract and raffinate are withdrawn continuously. This operation is repeated by shifting the(More)
Optimization problems with partial differential equation (PDE) constraints arise in many science and engineering applications. Their robust and efficient solution present many mathematical challenges and requires a tight integration of properties and structures of the underlying problem, of fast numerical PDE solvers, and of numerical nonlinear(More)
1. Abstract The past decade has seen a variety of operating modifications for Simulated Moving Bed (SMB) processes, including Three-Zone, VARI-COL, and PowerFeed. In recent studies, we have shown that these can all be embedded within a superstructure optimization problem with time-variant flow rates. Moreover, the resulting dynamic optimization problem has(More)
A new improvement based on outlet fractionation and feedback has been developed for simulated moving bed (SMB) chromatography. In this contribution, this fractionation and feedback SMB (FF-SMB) concept is extended to the general scenario which integrates a simultaneous fractionation of both outlet streams. A model-based optimization approach, previously(More)
A novel modification of simulated moving bed (SMB) technology, referred to as fractionation and feedback SMB (FF-SMB), has been introduced recently. This concept is based on fractionating one or both outlet streams and feeding the off-spec fractions back into the unit alternatingly with the original feed mixture. In this paper, the optimization problem of(More)
In this article, we extend the simulated moving bed reactor (SMBR) mode of operation to the production of propylene glycol methyl ether acetate (DOWANOL™ PMA glycol ether) through the esterification of 1-methoxy-2-propanol (DOWANOL™ PM glycol ether) and acetic acid using AMBERLYST™ 15 as a catalyst and adsorbent. In addition, for the first time, we(More)
An enrichment step is proposed to simulated moving bed chromatography with fractionation and feedback (FF-SMB), a new variation of SMB, to concentrate recyclates before they are fed back into the unit. Effectiveness of this operation is evaluated by systematic optimization studies. Case studies reveal that enriching recyclates is advantageous to FF-SMB and(More)