I need rate expressions for reactions of tatoray process in order to design reactor. Could you please help me?
I don't have kinetics but I have attached quite a bit of information about the process. Let me know if you need more infrmation
Rick Manner,
Many thanks for your contributions. Unfortunately, I already have information regarding process description and process flow diagram those mentioned in files you shared.
Hello
I recommend you this paper : " Kinetics of Toluene Disproportionation: Modeling and Experiments", Authors : Marcos W. N. Lobão, André L. Alberton, Sílvio A. B. V. Melo, Marcelo Embiruçu, José L. F. Monteiro & José Carlos Pinto, Ind. Eng. Chem. Res., , 51 (1), pp 171–183, 2012.
Link :
Article Kinetics of Toluene Disproportionation: Modeling and Experiments
I can send you the paper in private if you cant't dowlnoad it.
I hope it can help you.
Best regards.
Mounir
The process is not really limited by kinetics. Reaction proceed close to equilibrium. The usual problem is a build up of ethylbenzene in the recyccle loop addind a catalyst with dealkylation activity (EB-> ethane + Benzene) is often the best way to debottleneck the system.
Hi dear,
I agree with Dr. Rick Manner ,. The reaction is not limited by kinetic. It depends also on operating conditions.
With my best regards!
Adel OUESLATI
Mounir Bouaifi ,
Thank you very much, Sir!) It actually helps. The file u shared is just one reaction's kinetic, while it is needed to find the kinetics of all other reactions.
Rick Manner , Adel Oueslati
Thank u very much for contributions!) It is clear operating parameters play import role on reaction itself. Therefore, I need to find reaction kinetics to see this relationship if it is possible.
The tatoray process is usually a part of an aromatics complex with BTX fractionation a tatoray (transalkylation to form mixed Xylene C7and C9+ aromatics) an Isomar to convet meta and ortho to para xylene and a Parex to separate P-Xylene from Ortho and Meta. equilibrium. Tatoray prodcut is usuually 8% PX or less Isomar product is typically 20-25% PX so there are large recycles you need to model the entire complex including BTX fractionation Isomar, Tatoray, and parex/dewaxer not just the tatoray.
If you insist on doing a kinetic analysis you can assume a poor TaorayParx at 80% aproach to equilibium and a good Tatoray at equilibrium.
The real difference between a state of the art well performing Paraxylene plants is ring loss. Some P-X complexes manage to have less than 1% ring loss (ring openening and loss to heavy aromatic combined) very poor P-X complexes can lose 10% of the rings.
Buildup of Ethyl-Benzene in the recycle loop often limts capacity.
Here is what a typical UOP aromatic flow scheme looks like. A lot of recycles.
https://www.honeywellprocess.com/library/marketing/whitepapers/new_HoneywellAromaticsSolutionsv1_Oct0107_whitepap.pdf
The word document is a diagram of the complex to help you understand the importance of all of the recycles
I recommend that you build a simplified simulation of the system including all of your recycles. Any of the Hysys or Aspen products are great for this but I have also done it with an Excel spreadsheet.
You will see that small amount of per pas ring losses are significantly magnified be the large recycle loops.
Kinetic limitations can be model as fraction of the distance to equilibrium (reversible first order kinetic rate constant) or simlpy "approach" to equilibrium as a fraction of the way to equilibrium or an equivalent equilibrium temperature. If you increase the approach to equilibrium (move farther away from equilibrium) the recycle rates will get larger and losses due to dealkylation, cracking, ring opening and formation of heavy compounds will also get larger. You can model these effect fairly easily in any simulator or a spreadsheet.
Most aromatic complexes I have seen become bottlenecked by the ethyl-benzene building up in the Isomar recycle loop. This bottleneck can be removed by replacing the transalylation catalyst with a catalyst the promote Ethyl Benzene dealkylaton. This change usually occurs a few years after start up when the operator finds a way to get more feed and debottlenecks the reformer.
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