Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Modelling Saponification of ethyl acetate in a tubular flow reactor

Teerati Songsamattapap

Please login with a confirmed email address before reporting spam

Any suggestion for modelling a saponification of ethyl acetate?

I tried to model a saponification of ethyl acetate for my senior project. The reaction is NaoH+EtOAC=>NaOAC+EtOH

There are 3 models that i tried to model.

The first model is 0 dimension model. I created a model with 0-dimension>Reaction engineering (re)> Plug flow reactor type> Liquid phase in mixture properties. I typed a reaction NaoH+EtOAC=>NaOAC+EtOH with a forward rate constant kf=0.11 [L/mol/s] I inputted a molar mass and density for each species. I studied a stationary plug flow with a volume range 0-1 m^3 with a step of 0.1. A result showed me a straight line of molar flow rate. (It should be vary along reactor volume right?) and also a graph does not consist of 4 species. It appeared only 2 species. Can anyone help me with what I am doing wrong?

**The second model is 2D Axisymmetric model. **

I adapted a model “Tubular reactor with Nonisothermal Cooling jacket” (A+B=>C, so i think if i add a product D, this model should be work) with 3 Physics interfaces: Coefficient form boundary PDE, Heat transfer in Fluids and Transport of diluted species. From this model, i changed these things 1. I changed a diameter to 5 mm diameter and a length to 22 m. length 2. I added a cD=(cA0*xA)/2 as same as cC 3. I changed rA=-Aexp(-E/Rconst/T)cA to rA=-Aexp(-E/Rconst/T)cA0((1-xA)^2) because it is a second order reaction A result showed me one region which does not vary along axial and radial direction. Can anyone help me with what I am doing wrong?

The last model is a helix tubular reactor I also adapted a model “Tubular reactor with Nonisothermal Cooling jacket” which i create a helix tubular reactor with 5 mm diameter. From this model, i changed these things 1. Under Transport Transport of diluted species> Transport properties>Convection>Velocity field>> I added uy=2u0(1-(x/Ra)^2-(z/Ra)^2) in y-direction 2. Under Heat transfer of Fluids>Fluid 1 >> I also added uy=2u0(1-(x/Ra)^2-(z/Ra)^2) in y-direction 3. I added a cD=(cA0xA)/2 as same as cC 4. I changed rA=-Aexp(-E/R_const/T)cA to rA=-Aexp(-E/R_const/T)cA0((1-xA)^2) An error appeared when i computed it. Can anyone help me with what I am doing wrong?

Thank you in advance.


0 Replies Last Post 2018年4月12日 GMT-4 11:52
COMSOL Moderator

Hello Teerati Songsamattapap

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.