Process simulation—batch SUPERPRO DESIGNER

For a batch process modeled in SuperPro Designer, Monte Carlo simulation can be performed by combining Monte Carlo formulation tools, such as Oracle Crystal Ball from Oracle Corporation (Redwood Shores, CA) and Risk from Palisade Corporation (Ithaca, NY) with SuperPro. Both Oracle Crystal Ball and Risk are Microsoft Excel add-in applications that enable users to assign probability distributions to input parameters, manage the Monte Carlo simulation calculations, record the values of output variables, and analyze them statistically. The communication between Oracle Crystal Ball or Risk and SuperPro is accomplished using Visual Basic for Applications (VBA) scripts written in Excel. A detailed Monte Carlo simulation example based on a variation of this process that utilizes Oracle Crystal Ball and SuperPro Designer is available in the literature [144]. 

Six major process simulators are widely used in the chemical process industries today. These are ASPEN PLUS, BATCH PLUS and HYSYS.Plant (Aspen Technology, Inc.), PRO/n (Simulation Sciences, Inc.), CHEMCAD (ChemStations, Inc.), and SUPERPRO DESIGNER (Intelligen, Inc.). In this book and the associated multimedia CD-ROM, coverage is provided of ASPEN PLUS and HYSYS.Plant, which are the two most widely used process simulators. It should be mentioned that once the principles of process simulation are understood, it is a relatively easy matter to switch from one simulator to another. 

In recent years, property information systems have become widely available in computer packages. Some are available on a stand-alone basis, such as PPDS2 (1997), while others are available within the chemical process simulators, such as ASPEN PLUS, HYSYS.Plant, PRO/n, CHEMCAD, BATCH PLUS, and SUPERPRO DESIGNER. Commonly, constants and parameters are stored for a few thousand chemical species, with programs provided to estimate the property values of mixtures, and determine the constants and parameters for species that are not in the data bank using estimation methods or the regression of experimental data. Virtually all of the property systems estimate the properties of mixtures of organic chemicals in the vapor and liquid phases. Methods are also provided for electrolytes and some solids, but these are less predictive and less accurate. 

As in the steady-state simulation of continuous processes, it is convenient to convert from a process flowsheet to a simulation flowsheet. To accomplish this, it is helpful to be familiar with the library of models (or procedures) and operations provided by the simulator. For example, when using SUPERPRO DESIGNER to simulate two fermentation reactors in series, the process flowsheet in Figure 4.25a is replaced by the simulation flowsheet in Figure 4.25b. In BATCH PLUS, however, this conversion is accomplished without drawing the simulation flowsheet, since the latter is generated automatically on the basis of the recipe specifications for each equipment item. 

With SUPERPRO DESIGNER and BATCH PLUS, caution must be exercised when introducing continuous operations into batch processes, as no warnings are provided when a continuous process unit is running dry. When a feed to a continuous unit runs dry, the simulator assumes that this unit is shut down and restarted when the feed returns. Clearly, sueh operation is infeasible for many units, such as distillation colunms and chemical reactors. Consequently, when continuous processes are included, it is important to check the results computed by the batch simulators to be sure that unreasonable assumptions have not been made. 

Have completed several exercises involving steady-state simulation using one of the four simulators, ASPEN PLUS, HYSYS.Plant, CHEMCAD, and PRO/II, and involv-ing batch process simulation using one of the two simulators, BATCH PLUS and SUPERPRO DESIGNER. 

Process simulators, steady state, dynamic, and batch, are used throughout the textbook (ASPEN PLUS, HYSYS.Plant, CHEMCAD, PRO/II, BATCH PLUS, and SUPERPRO DESIGNER). This permits access to large physical property, equipment, and cost databases... 

Batch Plus (now called Aspen Batch Process Developer), a recipe-driven simulator that targeted batch pharmaceutical processes. Around the same time, Intelligen (Scotch Plains, NJ) introduced SuperPro Designer. The initial focus of SuperPro Designer was on bioprocessing. Over the years, its scope has been expanded to support modeling of fine chemicals, pharmaceuticals, food processing, consumer products, and other types of batch/semi-continuous processes. 

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