3 replies to this topic

[Geer_Lu]

Hello,

 

I am revamping amine scrubber in a hydrotreater unit. Since the new feed is a blend of gas oil and rapeseed oil, there will be CO2 in the recycle gas. Based on the excisting conditions (MEA concentration 20% and temperature in the regenerator reboiler 125 C) rich amine loading was calculated to be 0.1 mol CO2/mol MEA.

 

Do we need to consider a reclaimer due to the MEA degradation in this case? And most importantly- what defines whether we need it or not?

 

Thank you.

[Bobby Strain]

You might ask your MEA supplier.

 

Bobby

[Art Montemayor]

I have designed, built, and operated my own MEA reclaimers in the field.  I have always recommended the proper use of reclaimers on amine solutions - specifically MEA.  I’ve operated these units in 20% wt. solutions as well as on 12-15% wt. solutions with a lot of success.  The success was related to the absence of corrosion and the control of the MEA solution quality and consumption.  I can upload some literature on the subject that I’ve transcribed to electronic files recently (and continue to do) that may help you answer your questions.  This information comes from gas conditioning experts who designed and operated MEA reclaimers in the past.  In my youth, I actively attended a lot of conferences on the subject since in my time this was a “black art” and little known.  Even the classical gas purification text books like Kohl & Risenfeld, Kohl & Nielsen, etc., don’t go into the design and operating details needed.  This is probably because they’ve never built or operated one.

 

I’ve always advocated that the best and most successful way to operate an MEA acid gas removal unit is to keep the solution as clean, pure, and low in concentration as you can afford.  I have operated mostly with 15% wt. MEA solutions as a max., without a so-called “reflux” on the stripper, with a constant 2-3% of solution flow reclaimed, full flow activated carbon filters, and a water scrubber on the MEA contactor gas product line.  These efforts resulted in record low MEA consumption, no corrosion, and constant process production with no upsets.

I can’t address your specific question on whether you “need” a reclaimer or not without studying the application through a detailed P&ID and basic design information.  But I can explain how to design and operate one or the details on what you should consider before applying one in a gas conditioning unit.

 

I also have a question: are you located in Russia - or perhaps Denmark?

[Max Domingues]

I have another question on a similar situation: on a natural gas stream contained with a some amount of MEG, which is the best way to separate? 

 

The MEG content is poisoning the amine on the amine tower. I must to remove the MEG (from 15 ppm to 4 ppm on the gas natural stream) and two options are in sight:

1 - Remove the MEG on the natural gas stream (big flow and maybe big $$) [Obs: this stream comes from a MEG reclaim unit, but some amount of MEG are still on the stream and need to be removed]

2 - When the amine solution is contaminated , could be possible to withdraw the MEG from amine solution ( i prefer this situation, but i did not find a best way to do it, yet).

 

Thank you!

 

Max