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[martzian]

Hello!

 

 

I am currently working on a simulation project in Aspen HYSYS for the production of Maleic Anhydride from n-butane via partial oxidation.

To avoid the traditional water absorption route (and the massive headache of converting the resulting maleic acid back into maleic anhydride), I decided to use an organic solvent for the absorption step. I chose Dibutyl Phthalate, inspired by the ALMA process.

 

 

However, I made a slight oversight: I completely ignored that water is a major byproduct of the n-butane oxidation reaction itself. Even though the absorber operates at conditions meant to keep water in the vapor phase, a small amount of water will inevitably interact with MAN in the liquid phase to form Maleic Acid.

I want to make my simulation as rigorous and realistic as possible, so I need to account for this. I have some questions for those experienced with this simulation:

 

 

How should I implement the hydrolysis reaction inside the DBP absorber in HYSYS? Should I model the absorber as a Reactive Distillation/Absorption column? If so, is it better to use a Kinetic or Conversion reaction set for this specific step, assuming a certain residence time in the column?

 

 

Since some maleic acid will inevitably form and drop to the bottom of the absorber along with the solvent and MAN, what is the best sequence of unit operations in HYSYS to model the dehydration of this acid back into maleic anhydride? Should I use a thermal dehydration reactor, or is an azeotropic distillation setup more appropriate for this specific solvent route?

 

 

Any advice, literature recommendations, or tips on how to handle this in HYSYS would be greatly appreciated!

Thank you!