5 replies to this topic

[naduken]

Hello everyone,

 

I am relatively new to using Aspen HYSYS and have been working on a simulation for a LTFT GTL process following a specific paper I found. Most of the simulation has gone well, but I have run into an issue with the PFR reactor.

 

The problem is that changing the reactor volume does not seem to affect the rate of the reaction or the conversion. The simulation results show that the reaction conversion reaches 91%, and when plotting the change of concentration of the products, it just shows a straight line that appears after a 0.01 m of reactor length (see the attached images).

 

These results are for a 1000m3 reactor (PBR), which is significantly different from the paper I am following, where the conversion should be 43% for a 1000m3 reactor and 91% for a 2100m3 reactor.

 

I have tried various solutions, such as checking the reaction kinetics, adjusting the feed conditions and specifications, and enabling explicit reaction calculations. However, the issue persists.

 

Can anyone offer any suggestions on what else could be causing this problem or how to fix it? Any advice would be greatly appreciated.

 

Thank you in advance.

 

Image links:

https://imgur.com/RSjyYzD

https://imgur.com/u96dKNC

Attached Files

•  image_2023-04-28_104400809.png   190KB   1 downloads
•  image_2023-04-27_211759043.png   505.69KB   0 downloads
•  image_2023-04-27_211737869.png   193.16KB   1 downloads

Edited by naduken, 28 April 2023 - 03:34 AM.

[SilverShaded]

Conversion is defined so reactor volumn is irrelevant, maybe you need to model as kinetic reactions?

[naduken]

Conversion is defined so reactor volumn is irrelevant, maybe you need to model as kinetic reactions?

the reaction is a kinetic RXN
i actually tryed both kinetic and heterogenous catalytic reaction
both gave the exact same result
 

[SilverShaded]

 

Conversion is defined so reactor volumn is irrelevant, maybe you need to model as kinetic reactions?

the reaction is a kinetic RXN
i actually tryed both kinetic and heterogenous catalytic reaction
both gave the exact same result
 

 

The screenhsot is fixed conversion
 

[naduken]

 

 

Conversion is defined so reactor volumn is irrelevant, maybe you need to model as kinetic reactions?

the reaction is a kinetic RXN
i actually tryed both kinetic and heterogenous catalytic reaction
both gave the exact same result
 

 

The screenhsot is fixed conversion
 

 

@SliverShaded can you elaborate more, i did model the reaction as Kinetic reaction
what's the issue exactly 

[SilverShaded]

 

 

 

Conversion is defined so reactor volumn is irrelevant, maybe you need to model as kinetic reactions?

the reaction is a kinetic RXN
i actually tryed both kinetic and heterogenous catalytic reaction
both gave the exact same result
 

 

The screenhsot is fixed conversion
 

 

@SliverShaded can you elaborate more, i did model the reaction as Kinetic reaction
what's the issue exactly 

 

Ok, bit hard to tell from the screenshots.  Is it an equilibrium reaction?  Did it get to equilibrium really fast (units?) and then it looks like nothing changes with more reactor volume?

Edited by SilverShaded, 02 May 2023 - 06:19 AM.