HYSYS

HYSYS steady-state Hyprotech Suite 900, 125-9 Avenue SE, hyprotech.com... 

This example shows the application of optimization of a process using HYSYS software. Refer to the website, www.mhhe.com/edgar, associated with this book. 

Hyprotech Ltd. HYSYM, HYSYS, HYCON. Calgary, Alberta (1998). 

Databases in process simulators such as Aspen (1998), HYSYS (1998), and ProII (1998). 

Hysys software package, 7 76 Hytrel, commercial block copolymer,... 

HYSYS and SPEEDUP PC and larger Dynamic and steady-state simulation of large processes with data base. 

For the software of particular interest here, refer to the following websites BERKELEY MADONNA, www.berkeleymadonna.com MODELMAKER, www. modelkinetix.com/modelmaker/ MATLAB, http //www.mathworks.com ACSL, http //www.aegisxcellon.com/ HYSYS and SPEEDUP http //www.aspentec.com... 

Abstract In this paper, we discuss the results of a preliminary systematic process simulation study the effect of operating parameters on the product distribution and conversion efficiency of hydrocarbon fuels in a reforming reactor. The ASPEN One HYSYS-2004 simulation software has been utilized for the simulations and calculations of the fuel-processing reactions. It is desired to produce hydrogen rich reformed gas with as low as possible carbon monoxide (CO) formation, which requires different combinations of reformer, steam to carbon and oxygen to carbon ratios. Fuel properties only slightly affect the general trends. 

The process simulation code Aspen-HYSYS 3.2 has been used for residential PEM fuel cell system calculations. Natural gas has been simulated as three different sources for hydrogen production. The chemical compositions of the natural gas fuel are summarized in Table 1. The average molecular weight of natural gas is around 16.6 kg/kmol. All simulation studies are performed based on this composition. 

The major units of the Aspen-HYSYS simulation for natural gas steam reforming based fuel cell system are presented in Figure 3. 

Table 1 gives the components present in the crude DDSO and their properties critical pressure (Pc), critical temperature (Tc), critical volume (Vc) and acentric factor (co). These properties were obtained from hypothetical components (a tool of the commercial simulator HYSYS) that are created through the UNIFAC group contribution. The developed DISMOL simulator requires these properties (mean free path enthalpy of vaporization mass diffusivity vapor pressure liquid density heat capacity thermal conductivity viscosity and equipment, process, and system characteristics that are simulation inputs) in calculating other properties of the system, such as evaporation rate, temperature and concentration profiles, residence time, stream compositions, and flow rates (output from the simulation). Furthermore, film thickness and liquid velocity profile on the evaporator are also calculated. 

Properties Obtained from HYSYS Commercial Simulator... 

System characteristics—crude DDSO (13) properties of the components and of the mixture calculated from the properties obtained from HYSYS (see Table 1) through the equations presented. Note that all errors mentioned, one for correlation, were suggested by the authors of the equations. 

As mentioned earlier, calculations of diffusional rate processes are difficult as they involve the solution of partial differential equations. Even for processes which are clearly diffusional controlled, such as absorption, chemical engineers normally simplify the calculations by assuming equilibrium stages and may instead correct for possible deviations by using efficiency factors afterwards. Most commercial process design software, such as HYSYS, AspenPlus and ChemCAD, make the assumption of staged equilibrium processes. 

Fig. 6.13. Information flow diagram for EFRAT and relation to HYSYS . Shonnard and Hiew. Environmental Science andTechnology, 34(24), 5222-5228 (2000).77 Copyright American Chemical Society and reproduced by permission.

The simulator packages such as Aspen Plus and Hysys may be useful in analyzing distillation column systems to improve recovery and separation capacity, and to decrease the rate of entropy production. For example, for the optimization of feed conditions and reflux, exergy analysis can be helpful. A complete exergy analysis, however, should include both an examination of the exergy losses related to economic and environmental costs and suggestions for modifications to reduce these costs. Otherwise, the analysis is only theoretical and less effective. 

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