6 replies to this topic

[SCLau]

Hi,

 

     I am a final year chemical engineering student and I have been asked to design a carbon dioxide absorption column by using MEA as solvent. I dont have any idea on how to start the design. I have to do a very detail design in this column such as sizing, simulation of the reaction in the column, sensitivity analysis ect. 

    I have done a packed column design before. But what i have done is a dilute system and i just follow the standard step given by Coulson and Richardson. 

    But in this case, the concentration of the carbon dioxide is quite high and it involve chemical reaction. It means that Henry's Law cannot be applied and i know that this is totally different from what i have been done before. The approach from Coulson and Richardson is no longer valid for this case.

    Can someone please enlighten me in this design? 

 

Thanks

 

 

[breizh]

SCLau,

Use the search engine in this forum,, Art Montemayor has written intensively on this subject .

Good luck

Breizh

[SCLau]

I have gone through some books suggested by Art. It helps me to understand the whole concept of the process. However, i still do not have any idea in finding the diameter and height of the column. Can you kindly enlighten me in this issue?

[Art Montemayor]

S.C. Lau:

 

If you have actually gone through some of the books suggested by me, then you have surely found the attached excerpts from "Gas Purification".

 

Kohl & Nielsen go into detail in their discussion of MEA absorbers and strippers in their book, so what seems to be your problem?   Please be specific and detailed in describing what your dilemma is so that we can concentrate on the help you may need.

 

 

 

 

 

Attached Files

•  Acid Gas Removal Design Criteria.docx   111.17KB   86 downloads

[SCLau]

I am current working on finding the enhancement factor of this system. I know how to find the liquid film mass transfer coefficient without the chemical reaction. However, i dont know how to calculate the mass transfer coefficient with chemical reaction?

 Can you please kindly enlighten me in this issue?

[Padmakar Katre]

I am current working on finding the enhancement factor of this system. I know how to find the liquid film mass transfer coefficient without the chemical reaction. However, i dont know how to calculate the mass transfer coefficient with chemical reaction?

 Can you please kindly enlighten me in this issue?

 

Hi,

As suggested by the forum members please go thru these books to understand the process design stuff. After the process design is over and to design the column & its internals (packings as you mentioned) search for the packing mass transfer coefficient correlations available in leading journals, articles. You will come across such useful references if you search in Google. Once you know the theoretical plates required, you can estimate the HETP or HTU for the selected packing and then the depth or packed bed height.

 

When you say column design there are two aspects,

1. Process design i.e. setting up key parameters such as operating pressure, temp & concentration of solvent based on how much CO2 is acceptable from the absorber ovhd. and once you are thru with process design,

2. Column design and it's internals design

 

Hope this helps you.

[SCLau]

My case right now is modeling of reactive absorption column. I have a lot of differential equation such as energy balance in gas and liquid phase, mass balance. I also have a lot of equation like enhancement factor and diffusivity. I have to solve everything in matlab and everything is related to each other. Now i dont know how to start. Can someone please enlighten me ?