Biomedical subjects

Mohammad Amanullah

Publications and source records attributed to Mohammad Amanullah.

3 recordsLinked to original sources

PubMed2006

Experimental implementation of identification-based optimizing control of a simulated moving bed process.

Experimental implementation of an optimizing controller based on identified model for the separation of nucleosides in a laboratory scale simulated moving bed (SMB) unit is reported in this study. The manipulative variables are the three external and one internal flow rates while the outputs are productivity, solvent consumption, and purities of extract and raffinate streams averaged over a switching period. The feedback information is the concentration profile of extract and raffinate measured online using two ultraviolet (UV) detectors. Experimental results show that the designed controller is able to operate the SMB units under optimal condition fulfilling the purity requirements. Besides, the controller demonstrated excellent performance in terms of rejecting disturbances that may occur during SMB operations.

Chromatography↗

PubMed2005

Optimization of a hybrid chromatography-crystallization process for the separation of Tröger's base enantiomers.

This paper presents an analysis of a hybrid process consisting of simulated moving bed (SMB) chromatography and crystallization and studies its performance for the separation of the Tröger's base enantiomers. The SMB is simulated using a detailed model including column efficiency, thus, implying a proper evaluation of the effect of column size on column efficiency and separation performance. The crystallization operations are accounted for through material balances, assuming equilibrium between enantiopure crystals and mother liquor. A genetic algorithm is used to optimize the combined process, using proper definitions of objective functions. Multi-objective optimization of this hybrid process for productivity and evaporation cost in terms of operating parameters, column length, and SMB feed concentration shows an optimum SMB purity value as a trade off between increased SMB performance and recycle of the mother liquor.

Adsorption↗

PubMed2005

Optimizing control of simulated moving beds--experimental implementation.

The operation of simulated moving beds (SMBs) at their optimal operating conditions is difficult and not robust. Therefore, it is common practice to operate SMB units far from their economic optimum in order to tolerate uncertainties in the system and minimize the effect of disturbances. Recently, we have proposed an on-line optimization based SMB control scheme that allows to exploit the full economic potential of SMB technology. The goal of this work is two-fold. Firstly, to experimentally evaluate and demonstrate the capability of the controller to optimize and operate the SMB units, thus delivering the products with maximum productivity and minimum solvent consumption. Secondly, to show the suitability of the controller even using a minimum of system information, thus making the detailed isotherm measurements redundant and saving time in the separation design phase. This paper reports and discusses the first experimental implementation of the control concept on a high purity separation of nucleosides (uridine, guanosine) with an eight-column four-section SMB where the species to be separated are retained on the source 30RPC stationary phase according to a linear isotherm.

Chromatography, Liquid↗