3 replies to this topic

[Ingridekle]

Hi,

 

I have problems making a reboiler absorber converge. 

 

The absorber has two inlet gas streams and are to separate C4 and C5+. It has a working pressure of 15 bars and 20 trays. I try to vary the specifications, but it will not converge. 

 

Does anybody know what the problem might be? 

 

 

 

 

[Bobby Strain]

You can use a regular distillation module and specify no reflux. You might need to start with some reflux until it converges, then reduce it. I often have problems with the reboiled absorber module.

 

Bobby

[ColinR33]

What is the function of the tower and what are you specifying?  Application can make a difference, and be careful you are not specifying something that cannot be achieved.

 

For a reboiled absorber (stripper) with one feed you should only have one degree of freedom, so only one spec to play with.  Typically operating pressure is defined and estimates for top and bottom temperatures can be input as well.   For this application I usually specify one of: reboiler duty, bottom temperature, bottom liquid vapour pressure or component fraction (these are not the only options, just the ones I use most often).  Eg, for a condensate stabilizer tower I typically specify the ethane content in the bottom liquid stream, or the RVP of the stabilized product.

 

Cheers,

[Propacket]

Post that file here. It will converge.