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Dear all,

Currently I am simulating in HYSYS a simple CO2 removal process using MEA 30 wt%. Regarding this, I have an enquire about the stripper performance: The reboiler duty and reboiler temperature are somehow proportional? Or they can vary independly?

I do know that in these type of processes the reboiler must supply heat for three different things: 1. sensible heat of the solution, 2. heat of desorption and, 3. Heat of vapor water stripping...

However, I dont know what determines the reboiler temperature???

I am simulating different cases with different lean and rich amine loadings, and so far, I have a got that as the temperature of the reboiler decreases the heat supplied by the reboiler increases....Why does it happend?

I will be very glad if somebody can help me...this is very important for a project that I am doing right now.

Best regards!

[Art Montemayor]

Luber:

A CO₂ removal process using an MEA solution of 30 wt%. is not simple. It is just not recommended nor practical. How did you come to select such a high concentration of MEA? It will rapidly degenerate and covert itself into a very corrosive and expensive solution to maintain.

The reboiler duty has nothing to do with the temperature required to carry out the vaporization of the water content there. The reboiler converts some of the water content into steam used for stripping the CO₂ out of the rich solution fed into the stripper. There is no relationship between the two. Regardless of the required reboiler duty, the temperature is always kept at the recommended 220 -230 ^oF – sufficient to generate the stripping steam and kept below the maximum decomposition temperature of the MEA.

Before you get involved in trying to simulate an MEA acid gas removal system you should read, study and thoroughly understand the information found in at least 3 classical text books on acid gas removal:

• “Gas Purification”, by Kohl & Riesenfeld;
• The GPSA Engineering Databook; and,
• “Gas Conditioning and Processing”, by John M. Campbell

If you want further details on the MEA CO2 removal system, I will be glad to help you. I designed, installed, and operated a lot of these units for quite a few years. However, if you want specific, detailed help you must also furnish specific, detailed basic data, scope of work, as well as produced calculations, schematic PFDs, and references.

Use the SEARCH machine on our Forums to find more information on this subject. I have answered and helped others on many, many threads in the past years.