Page 25 - Process simulation and control using Aspen

18 PROCESS SIMULATION AND CONTROL USING ASPEN

Aspen Plus suggests a number of possibilities. Among them, select a suitable
component name (N-BUTANE) and then click on Add. Automatically, the Component
name and Formula for Component ID N-C4H10 enter into their respective columns.
For last two components, we follow the same approach. When all the components are
completely defined, the filled component input form looks like Figure 1.22.

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FIGURE 1.22
The Type is a specification of how Aspen calculates the thermodynamic properties.
For fluid processing of organic chemicals, it is usually suitable to use 'Conventional*
option. Notice that if we make a mistake adding a component, right click on the row
and then hit Delete Row or Clear.

Specifying property method
Press Next button or choose Properties I Specifications from the Data Browser. Then if
we click on the down arrow under Base method option, a list of choices appears. Set the
SYSOPO' method as shown in Figure 1.23.
A Property method defines the methods and models used to describe pure component
and mixture behaviour. The chemical plant simulation requires property data. A wide
variety of methods are available in Aspen Plus package for computing the properties.
Each Process type has a list of recommended property methods. Therefore, the Process
type narrows down the choices for base property methods. If there is any confusion, we
may select All' option as Process type.
'
Specifying stream information
In the list on the left, double click on Streams folder or simply use Next button. Inside
that folder, there are three subfolders, one for each stream. Click on inlet stream F, and
enter the temperature, pressure, flow rate and mole fractions. No need to provide any
data for product streams L and V because those data are asked to compute in the present
problem (see Figure 1.24).

This property method assumes ideal behaviour for vapour as well as liquid phase.

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