Software packages Aspen

MicroMENTOR is an educational package for solving distillation problems and includes MCCABE, PONCH, and BATCH for the MaCabe-Thiele, Ponchon-Savarit, and Batch binary distillations (11). The commercially available distillation software packages have been surveyed (15). Por reactive distillation, ASPEN software (16) is weU-known and widely adopted. 

This structure assures correct pressure-flow solutions and, thus keeps the model consistent. Software packages, such as ASPEN Dynamics , will ensure this correct coupling. In general, two flow calculating devices cannot be connected directly, but must have a pressure (typically a volume) element in between. Two flow devices can be connected if a single equation can be written that describes the pressure drop over the connected section. For instance, some programs allow two pipe models to be connected. 

Throughout this book, we have seen that when more than one species is involved in a process or when energy balances are required, several balance equations must be derived and solved simultaneously. For steady-state systems the equations are algebraic, but when the systems are transient, simultaneous differential equations must be solved. For the simplest systems, analytical solutions may be obtained by hand, but more commonly numerical solutions are required. Software packages that solve general systems of ordinary differential equations— such as Mathematica , Maple , Matlab , TK-Solver , Polymath , and EZ-Solve —are readily obtained for most computers. Other software packages have been designed specifically to simulate transient chemical processes. Some of these dynamic process simulators run in conjunction with the steady-state flowsheet simulators mentioned in Chapter 10 (e.g.. SPEEDUP, which runs with Aspen Plus, and a dynamic component of HYSYS ) and so have access to physical property databases and thermodynamic correlations. 

Instructions on how to use the different software packages (POLYMATH, MATLAB, and ASPEN PLUS) to solve examples. 

A large number of ordinary differential equation solver software packages (i.e., ODE solvers) which are extremely user friendly have become available. We shall use POLYMATH S to solve the examples in the printed text. However, the CD-ROM contains an example that uses ASPEN, as well as all the MATLAB and POLYMATH solution programs to the example programs. With POLYMATH one simply enters Equations (E4-7.3) and (E4-7.4) and the corresponding parameter value into the computer Table E4-7.1) with the initial (rather, boundary) conditions and they are solved and displayed as shown in Figure E4-7.1,... 

ASPEN is a process simulator that is used primarily in senior design courses. It has the steepest learning curve of the software packages used in this text. It has a built-in database of the physical properties of reactants and products. Consequently, one has only to type in the chemicals and the rate law parameters. It is really too powerful to be used for the types problem with heat effects in order to help familiarize the student with ASPEN. 

This appendix gives a brief overview of the methods that are preprogrammed in the software packages Excel, MATLAB, Aspen Plus, and FEMLAB. The interested reader may pursue the references for more specific details. 

FLOWSHEETER = Process diagram calculation software package. Examples ASPEN , PROII , HYSIS . 

Instructions are included on how to use not only the software package. of Polymath. MATLAB, and FEML. B. but also on how to apply ASPEN PLUS to solve CRE problems. Tutorials with detailed screen shots are provided for Polymath and FEMLAB. 

The DODS software package can be used to complete most of the examples and tutorials in this book. The package has been written in Matlab, but has been complied such that it may be used on a computer without Matlab installation. It is also useful as an independent design tool and, as shown in the examples in the book, the results obtained can be used as initialization to rigorous simulation packages such as Aspen Plus . The DODS package consists of five independent packages ... 

The MESH equations constitute a nonlinear and strongly coupled system of algebraic equations since the equilibrium ratios Ki j and the enthalpies and are complex functions of temperature and concentrations. The system (5.2-71) is numerically solved by the iterative Newton-Raphson algorithm. Commercial software packages (e.g., ASPEN, HYSYS, CHEMCAD) contain both the mathematical solver and the required system properties, such as vapor liquid equilibria and enthalpies. 

Widely distributed software packages like ASPEN+ [75] and SPEEDUP [76] make stationary and instationary process simulations available for many engineers. An extensive summary of this subject is given in a book edited by Schuler [77]. A pioneering book about process flowsheeting has been written by Westerberg et al. [78]. In Germany the DIVA [77, 79] simulator for instationary simulation of complete chemical plants is in industrial use. 

The results obtained by hand calculations and the available software packages, Hysys, PRO/II, Aspen Plus, and SuperPro Designer, are almost the same. 

Ethyl chloride is produced by the gas-phase reaction of HCI with ethylene over a copper chloride catalyst supported on silica. The feed stream is composed of 50% HCI, 48 mol% C2H4, and 2 mol% Nj at 100 kmol/h, 25°C, and 1 atm. Since the reaction achieves only 90 mol% conversion, the ethyl chloride product is separated from the unreacted reagents, and the latter is recycled. The separation is achieved using a distillation column. To prevent accumulation of inerts in the system, a portion of the distillate is withdrawn in a purge stream. Design a process for this purpose using Hysys, PRO/II, Aspen Plus, and SuperPro software packages. 

The reaction of ethylene (C2H4) and hydrogen chloride (HCI) over a copper chloride catalyst supported on silica to produce of ethylene chloride (CjHjCI) is a highly exothermic reaction. In this example, the reaction is assumed to take place in an isothermal conversion reactor. The heat evolved from the reaction is removed from the reactor to keep the reaction at constant temperature. The reactor effluent stream is compressed, cooled, and then separated in a flash unit followed by a distillation column. The flash and distillation top products are collected and then recycled to the reactor after a portion of the stream is purged to avoid accumulation of an inert component (Nj). The recycled stream is depressurized and heated to the fresh feed stream conditions. The liquid from the bottom of the flash enters a distillation column where ethyl chloride is separated from unreacted HCI and ethylene. The entire process is simulated using Hysys/Unisim, PRO/II, Aspen, and SuperPro Designer software packages. 

Become skilled at how to simulate the basic chemical processes using software packages such as PRO/II, Hysys, Unisim, Aspen Plus, and SuperPro Designer. 

Putting aU these aspects together, the operational behavior could be modeled for air classifier and sieve hammer mills i.e., the PSD could be predicted for various operating conditions such as hammer speed or screen openings. The results served as input for models which were incorporated into the SolidSim software which is now part of the Aspen software packages. 

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