2 replies to this topic

[Truth]

 Methanol part 1.zip   115.06KB   20 downloadsI am working on designing a methanol plant.The first half is done in Hysys.The problem is that the Hysys flow sheet is not converging.

 

I have to cool down the SRF outlet stream from 980 to 70 degrees C and heat up Oxygen and NG gas feed.SO,I used 3 heat exchangers to cool the SRF outlet and heat the O2,NG feed and boil and heat up bottom outlet of Separator S501(almost water).|I also need to get feed NG and O2 to 35 bar from 1 bar so I used compressor-cooler-compressor combination.

 

I tried the following steps but stil no convergence:

 

1.Keeping centrifugal compressor outlet temperature below 204 degree C and compression ratio below 7 and adiabatic efficiency upto 85%.

 

2.I have also set DP for all heat exchangers to zero.

 

Can you please help me?

 

I have attached the .hsc file in compressed form for understanding the process. I will be grateful if anyone can kindly help me in this.

Edited by Truth, 29 September 2020 - 06:34 AM.

[FRBChemE]

COCO has a complete down loadable Methanol from syn gas Flow sheet.  Likewise if you are familiar with DWSIM, you can down load a Fossee flowsheet, number 152  Methanol Synthesis.  One of them may be enough to tell you about processing conditions to give you a hint as to why no convergence.

[Bobby Strain]

You sound like a novice user of HYSYS. You should simplify your flowsheet and observe what happens. Then begin to add back the more complex operations such as exchangers. You must learn more about HYSYS before you can be successful with your simulations. It doesn't happen with your first attempt. Good luck.

 

Bobby