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Dear Friends,

I am trying to model Acetic acid cracking to Ketene in PRO-II, the reaction is as described below:

CH3COOH = CH2CO + H2O (in presence of phosphate catalyst)

I am trying to model the pyrolysis reaction by using a PFR in PRO-II, the thermodynamic property i am using is UNIFAC. The reaction kinetics is first order. Inlet conditions are 2 T/h of feed (90% Acetic acid + 10% Water @ 120°C & 200 mmHg abs)

I know that this reaction is endothermic starting at 650-700°C. But i am totally clueless on the reaction parameters. For egs. in PRO-II i have to enter Rate = A x Exp [-E/RT] x T^n and i am totally clueless on parameters like A, E and n. Furthermore, i also do not understand how this rate equation takes care of endothermicity of the reaction.

Searching some literature i was able to find out the above parameters for acetone cracking to ketene, and these are A=8314.8, E= 67999 cal/mol, n=0. But since my reaction is involving acetic acid, i think that using the above parameters won't help.

If anybody has done such an exercise previously then please help. Please note that i am fired heater engineer and this exercise is for my academic interest and my intention of doing such an analysis is to obtain tube side parameters in an acetic acid pyrolysis reaction furnace.