×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

MDEA concentration

MDEA concentration

MDEA concentration

(OP)
What is the effect of MDEA concentration on H2S absorption in Amine Absorber. We are using 30% amine solution. If more concentrated solution is used, what are the advantages in absorption and regeneration? Is it true that upto 40% MDEA concentration absorption is nearly constant?

RE: MDEA concentration

Lean amine acid gas loading, lean amine temperature, and absorber pressure are more likely to have a noticeable impact on H2S level in your treated gas, i.e. lower lean H2S loading, lower temperature, and higher pressure all favor H2S absorption.  Higher wt % solution will give you more moles of amine per unit volume of solution circulated.  If you run high rich loadings and cannot circulate more amine for some reason the higher solution strengths will help the rich loading.  I doubt you'll see much of an impact on treated gas H2S concentration vs. amine strength unless you're running your rich loadings on the high side.

Higher solution strength also tends to increase hydrocarbon solubility in your solvent, particularly troublesome BTEX components if they are present in the gas stream you're treating.  Its been my experience that higher strength amine solutions have higher foaming tendency and foam stability in the amine regenerator too, particularly with higher molecular weight amines such as MDEA.

There are a lot of technical articles available on amine systems here:  http://www.bre.com/Resources/TechnicalArticles/tabid/96/Default.aspx

The Laurance Reid CDROMS have a lot of good amine unit information if you have access to them as well..

Do you have enough instrumentation available to know the temperature profile in your absorber?  If not, climbing the tower and shooting temps at inspection ports can get the job done too.  Knowing the temperature profile and how many "cool" trays you have can be particularly useful for troubleshooting absorbers.

What kind of gas are your treating, is it Claus tail gas, recycle hydrogen, sales gas?  The type of system can have a big impact on potential problems and solutions.

RE: MDEA concentration

(OP)
Response to Jason5000 : 1. we have lean amine, rich amine, inlet and outlet gas temp indicators. Tray wise indicators are not there. 2. We are treating FCC fuel gas.

Additionally the first 5 trays 0f 35 tray absorber are used for water wash with continuous fresh water circulation.


 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources