rajasingh:
The subject of amine CO2 strippers is one that has been dealt with on our forums in many, many threads ad nauseam. This application is a basic and simple one that is older than I am! Mr. R. R. Bottoms patented it in 1930 and described it in detail. The Girdler Corporation built many plants based on it and I personally designed, built, and operated several units in the field with success. As I have stated many times before: the amine CO2 stripper is a simple one requiring no more than 10 simple trays. The calculated theoretical stages for stripping amine are approximately 3-4. So why are you complicating your life and such a simple unit operation?
Read and ponder carefully what PingPong and Bobby Strain are telling you:
- Kohl & Nielsen, to my knowledge, never designed or built amine strippers. I have, and thoroughly agree with PingPong on his comment;
- Bobby is right on; you can best spend your time drinking some good draft beer rather than trying to apply multiple pass trays on such a simple operation.
How did you - or anyone else - arrive at 20 actual trays needed to strip out the CO2? You yourself admit that it is “readily” stripped out!
Structured packing is easily applied and why do you expect the MDEA to “foam”? What evidence or experience are you basing yourself on? Kohl & Nielsen mention that some amine units have been reported as foaming and suggest some causes - but I don’t believe they recommend that you design for this to happen to you. Read their report on page 10:
“Packed columns are gaining favor for a wide range of applications because of the development of packings that offer superior performance, as well as the emergence of more reliable design techniques. The most commonly used packing elements are packed randomly in the column. Non-random ordered (or structured) packings were originally developed for small scale distillation columns to handle difficult separations. Their use has recently expanded, however, and ordered packings are now offered by several companies for large scale commercial applications. The current availability of performance data and rational design procedures makes the use of ordered packing worth considering for cases requiring high mass transfer efficiency and low pressure drop.”
Also read what they state in “Tray Versus Packed Columns”, page 111:
“The choice between trays and packing is somewhat arbitrary because either can usually be designed to do an adequate job, and the overall economics are seldom decisively in favor of one or the other. At this time, sieve tray columns are probably the most popular for both absorbers and strippers in conventional, large commercial amine plants; while packed columns are often used for revamps to increase capacity or efficiency and for special applications.”
Kohl & Nielsen are NOT EXPERTS in designing or building amine plants. They have never claimed to be that. They are expert, knowledgeable reporters who have documented a lot of information and data on the subject and put it into an organized book form.
In my opinion, you are trying to use an Alfa Romeo as city taxi when you should be applying the K.I.S.S. rule of engineering.