3 replies to this topic

[ikha21]

Hello everyone,

 

 

I am a student and new to Aspen Plus. I am working now on an Acid Gas Dry Scrubbing with Calcium Hydroxide Simulation using Aspen Plus. The gas is actually flue gas which contains some acid gases like HCl, HF, and HBr. And these acid gases must be removed through chemisorption process with solid Phase Ca(OH)2 in a reactor.

 

The property method i use is NRTL, and the stream class is MIXCISLD, since it involves conventional gases, solid Ca(OH)2, and other salts in solid phase as product reactions. So, by using RGibbs reactor block, i expect that the Ca(OH)2 solid will react with HCl, HF, and HBr gases. I already tried both calculation options:

 

1. Calculate Phase and chemical Equilibrium

2. Restrict chemical Equilibrium, specify temperature Approach or reactions (i specified all the reactions scheme i expected)

 

But both calculations have the similar results. The reactions occur are only occur between O2, SO2, SO3, NO, and NO2. Meanwhile the Ca(OH)2 does not react at all.

 

I could not find the reason why does it happen, and how to make the Ca(OH)2 reacts with the gases. So, how should i solve this Problem.

 

Thank you for your reply, questions, and sharing.

 

 

Best Regards,

Ikha

 

 

[serra]

the reactive flash which I utilize regularly (that included in Prode Properties) for reactants includes the values of Gibbs energy of formation stored in database,

you may check in Aspen for the correct value of Calcium Hydroxide,

also it seems strange that flash doesn't include a solid phase, you may check if some specific settings is required...

[ikha21]

Hello Serra,

 

 

Thank you for your reply.

 

I already checked by retrieving Parameter results for heat of Formation (DHSFRM) and Gibbs Formation (DGSFRM) of all solid components. The value of both Parameters are quite similar from other references. So there is no Problem in the database.

 

Do you know maybe there is any rules for using RGibbs reactor block for gas-solid reactions?

 

Thanks and best regards,

Ikha

Edited by ikha21, 10 July 2018 - 08:10 AM.

[serra]

no, the software which I know doesn't require specific settings (solving gas-solid reactions) ,

maybe there is an example in operating manual...