Question: How can Aspen perform calculations on virtual substances?
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For example, I want Aspen to calculate the conversion at the outlet of a plug flow reactor. The reaction is A→B, with both A and B being virtual components. Then, for reaction kinetics, I simply entered the values (the data or equations used are not real; they are fabricated). Such problems certainly have no practical value, but they are very useful in chemical engineering education. For such problems, how to use Aspen for calculations? ——It first asks me to enter the reaction components, but I can’t enter them? Could someone with more experience give me some advice? Thank you.
The “virtual substances” you mentioned are what Aspen typically refers to as “Hypothetical Components”; they can be defined and used directly, without having to be actual chemicals that exist in reality. The specific procedure is as follows: 1. During the component creation phase: – Do not select the default database component; instead, create a custom component directly. - Method: Go to Aspen Properties → click on “Components” on the left → “User Defined” or “Hypothetical” (hypothetical/virtual). - For virtual components, such as A and B, there is no need to enter actual structural information. Just enter simple parameters, such as values for molecular weight, density, etc. (These can be made up arbitrarily). 2. Go to the Reaction module: – Define a Reaction Set, within which you define your reactions: A→B ； - By setting your own dynamic expression (you can define the dynamic equation as you wish), you can create your virtual reaction. 3. In a simulated environment (such as a Plug Flow Reactor, PFR): - Select the hypothetical components and set of hypothetical reactions you just defined ； - Adjust conditions such as inlet component composition, flow rate, temperature, and pressure ； - By performing the simulation calculation, the conversion rate and outlet data can be obtained. This method does not involve real components, nor is it necessary to consult a database. For teaching purposes, it enables convenient and rapid demonstration of the reaction behavior under different process conditions and kinetic conditions. Summary: The key is to use Aspen to customize hypothetical or user-defined components, and in combination with custom reaction kinetics, it is possible to carry out completely virtual computational analyses. .
Thank you for the advice; I’ll do as you suggested and give it a real try.