Process design computer-assisted

The purification of value-added pharmaceuticals in the past required multiple chromatographic steps for batch purification processes. The design and optimization of these processes were often cumbersome and the operations were fundamentally complex. Individual batch processes requires optimization between chromatographic efficiency and enantioselectivity, which results in major economic ramifications. An additional problem was the extremely short time for development of the purification process. Commercial constraints demand that the time interval between non-optimized laboratory bench purification and the first process-scale production for clinical trials are kept to a minimum. Therefore, rapid process design and optimization methods based on computer aided simulation of an SMB process will assist at this stage. 

We have already emphasized our view that the evaluation of chemical reactions and synthetic pathways is of preeminent importance in any system for computer-assisted synthesis design or reaction prediction. The quality of the evaluation process will determine to a large extent the overall quality of such a system. 

The pharmaceutical industry has pioneered in the application of computer-assisted drug design methods in product research. To a significant degree this is a consequence of the direct use of computational chemistry in enhancing the efficiency of the chemical lead optimization process. 

Computer assisted processing and design of reaction mechanisms 6.1 INTRODUCTION... 

Riester et al. [103] presented a series of thrombin inhibitors that were generated by using powerful computer-assisted multiparameter optimization process, which was organized in design cycles starting with a set of 170 ran-... 

Many chemical and petroleum companies are now using Process Industry Practices (PIP) criteria for the development of P IDs. These criteria include symbols and nomenclature for typical equipment, instrumentation, and piping. They are compatible with industry codes of the American National Standards Institute (ANSI), American Society of Mechanical Engineers (ASME), Instrument Society of America (ISA), and Tubular Exchanger Manufacturers Association (TEMA). The PIP criteria can be applied irrespective of whatever Computer Assisted Design (CAD) system is used to develop P IDs. Process Industries Practice (1998) may be obtained from the Construction Industry Institute mentioned in the References. 

To operate SMB chromatography a lot of parameters (column diameter, column length, total column number and number of columns per section, eluent, feed, raffinate, extract and recycle fluid flow and switch time interval) have to be chosen correctly. Therefore, design and process optimization should be done by computer simulations. It is much more difficult to optimize SMB during nonlinear conditions as compared to linear conditions. In fact, empirical approaches for optimization during overloaded and non-linear conditions are in most cases even impossible [96, 97], Computer-assisted optimization is therefore especially important for chiral separations since these CSPs have in general lower saturation capacities compared to non-chiral columns (see paper III). 

---