6 replies to this topic

[Mojimee]

 Please can someone help me with this problem, Fatal error - zero diagonal in column matrix in Acid Gas Sweeting with DEA with HYSYS. I have tried adjusting the spec...

 

 

 Zero diagonal in column matrix.PNG   69.9KB   5 downloads

 

 

Regards

 

Mojimee

  

[RockDock]

You should probably ask Aspen Support.

[thorium90]

Your column iterations has diverged. Choose other initial conditions to initialize the solver or tweak solver tolerances or solver type.

[RockDock]

what do you mean by adjusting the spec? Are you trying to get Hysys to design a column for a given H2S or CO2 spec? That is about the worst way to go about it. Not only is Hysys very inaccurate when it comes to sweetening, you are asking it to do the impossible.

 

You should use ProMax for this. And even then, you should use solvers for circulation rate, reboiler duty, lean cooler and lean/rich exchanger. Size your absorber based on the gas flow rate and your regenerator based on your circulation. Your specs should be met after you perform your parametric studies for that unit. Do not use solvers for the sweet gas spec. That will make it difficult for any simulator, let alone Hysys, which not even close to being predictive for sweetening.

[chyke7]

Dear Rock,

Please do you have a step by step guide for designing CO2 Absorption using ProMax?

[IUR]

Please Choose other inlet conditions for your column and change spec value from minimum to max gradually. When this Fatal error appears this is the indication that HYSYS has stuck to some limit due to the abnormal input or spec which you have marked / crossed . Try refreshing your spec and change values.

[RockDock]

I don't have a step by step guide for ProMax, but the creators of the software offer free training (which I've attended many times). They also have several youtube videos for reference.