31 replies to this topic

[alchemist]

 

That's correct. It's a good point to bring up. ProMax uses the residence time (calculated by the column internals and flow rates) to rigorously calculate the progression of the reactions. I like that because there are no fudge factors to deal with. ProTreat uses "enhancement factors" to deal with the non-equilibrium effect. Both approaches work, but since amine sweetening is primarily limited by reaction kinetics, I trust the ProMax approach slightly more.

The residence time in ProMax is an interesting and tricky thing. I don't think ProMax is really a rate-base column model. RockDock, do you have some research literature in that? The rigorous model should solve the mass transfer rate using a series of ODEs, like what used in ProTreat. The rigorous model may have problems in convergence. The stage efficiency / enhancement factor is also a rigorous rate-base approach, which is used by the DBR amine. There are tons of research in the rigorous rate-base model and in the enhancement factor model. These two models are really the models that rigorously calculate the reaction kinetics. I personally don't think the DBR amine is a marketing ploy by big companies. On the contrary, I think ProMax is more successful in marketing their products.

 

 

I thought one does not to provide the residence times for the packed columns.  ProMax calculates the residence times for the trayed columns, but not so for the packed columns.  I typically solve for the packed column, copy the residence time, convert it to packed columbn and use the residence times copied earlier.  If there is a way to calculate the residence time for the packed columns as well, I am not aware of it.

 

One area where I have issues is to calculate the # of trays needed, and the packing ht for the packed column.  If anyone has any tips on this, please share.

 

Thanks

 

-AC

[RockDock]

You are right that the residence time is calculated by ProMax for trayed columns. I have not done many packed columns, so I don't think I am the right one to help you with that. I've done, maybe, two in the past 10 years. Both of those times BRE helped me create the model. Perhaps they can help you with that.

[AlbertHahn]

 

 

That's correct. It's a good point to bring up. ProMax uses the residence time (calculated by the column internals and flow rates) to rigorously calculate the progression of the reactions. I like that because there are no fudge factors to deal with. ProTreat uses "enhancement factors" to deal with the non-equilibrium effect. Both approaches work, but since amine sweetening is primarily limited by reaction kinetics, I trust the ProMax approach slightly more.

The residence time in ProMax is an interesting and tricky thing. I don't think ProMax is really a rate-base column model. RockDock, do you have some research literature in that? The rigorous model should solve the mass transfer rate using a series of ODEs, like what used in ProTreat. The rigorous model may have problems in convergence. The stage efficiency / enhancement factor is also a rigorous rate-base approach, which is used by the DBR amine. There are tons of research in the rigorous rate-base model and in the enhancement factor model. These two models are really the models that rigorously calculate the reaction kinetics. I personally don't think the DBR amine is a marketing ploy by big companies. On the contrary, I think ProMax is more successful in marketing their products.

 

 

I thought one does not to provide the residence times for the packed columns.  ProMax calculates the residence times for the trayed columns, but not so for the packed columns.  I typically solve for the packed column, copy the residence time, convert it to packed columbn and use the residence times copied earlier.  If there is a way to calculate the residence time for the packed columns as well, I am not aware of it.

 

One area where I have issues is to calculate the # of trays needed, and the packing ht for the packed column.  If anyone has any tips on this, please share.

 

Thanks

 

-AC

 

ProMax is essentially an equilibrium column model. It is not surprising that you have issues to calculate the # of trays needed and the packing ht.

[aqassam]

Have you looked at the new Acid Gas property package in Aspen HYSYS? There's a pretty cool technological improvement to rate-based modeling in v8.3+ which is different from the old DBR Amines technology. Contact me if you have any questions. 

[alchemist]

I have not looked into Aspen HYSYS.  I initially started out with Aspen Plus but was having issues with convergence.  Someone recommended ProMax for amines sweetening.  Lit search suggested it works well fo amine sweetening, plus their customer support was very helpful, so started using that.

 

I have some experience with Aspen Plus.  I will look into HYSYS ?  How steep is the learning curve for HYSYS ?

 

Thanks,

 

-AC

[gegio1960]

I've designed about 20 Amine washing & regeneration plants that have been built and succesfully operated (both in Refineries and Gas Plants).

My simulator choice for Amine is PROMAX. We purchased it about 20 years ago (as TSWEET) because the design with HYSYS and PROII wasn't in accordance with our previous calculations, based on experimental curves.

I know that, in recent years, Aspentech and Honeywell were looking for something to add to their process simulators to improve the performance for the Amines... but I can't say they succeeded.

[JuLiOz86]

On my experience, ProMax and Protreat are the simulators that best fix to the reality in Amine Sweetening Plants.