3 replies to this topic

[mhameran]

i have an issue & wud really appreciated if any experts here can give us some clues to work on. here it is:

we have ARU (amine regeneration unit), capacity 265 m3/h, bottom temp is controlled at 124 - 126 C, pressure 1.08kg/cm2g. our problem is when we want to increase the strength to 37wt% from 30wt%, we add fresh amine but the strength did not increased!

wut we hv confirmed so far:
1. no leak
2. no leak ( i know this is the 1st thing ppl will ask)
3. less loading
4. foaming?
5. flooding?

we checked the reflux for amine, and hardly to get 1%, but with the method now changed to IC and GC as well... Lab came to us and indicated the results were between 38 - 46 wt% !!!

we thought the analysis was wrong but the verifications done and the result still same. wut u guys can suggest? thanx.

[ravi.s]

Dear mhameran,

Generally, it is recommended to increase the concentration of Amine in the steps of 5 to 6wt% and operate the plant say about 10 to 12 hours for stabilization by monitoring the plant performance. Whenever calculated fresh amine is added in the system to increase the Amine strength, the amine inventory will increase. To maintain the same inventory, equivalent quantity of reflux water from amine system needs to be removed. if the water is not removed, then due to the increase in inventory, Amine concentration will be less than the calculated.


Further to avoid amine losses, it is to be noted that operating water wash column downsteam to the absorber reduces amine entrainment/carryover in to the sweet gas. Also treated gas coolers are commonly used to return water along with portion of the amine to main circulation system.

[Satyajit]

Hi
I think what Ravi said is alright. I would like to add following:
1. Please check your filtration activities. Are you doing frequent backwash of your filter and losing solution.
2. You should try to reduce your stripper pressure and bottom temperature. You may be losing amine with overhead condensate.
3. Did you check the composition of your make up.
4. Do you have in degradation in the system.
Regards,
Satyajit

[anjumaziz]

Mr. Ravi & Mr. Satyajit have suggested the right way to figgure out your problem. Further in addition to all above, have you find any carryover from amine unit to next unit (possibly if dehdration unit or anyother. Also do the analysis of fresh amine that is to be cahrged into the system and complete anlysis of circulating amine i.e Ph, Fe contents, heat stable salts etc.
What about the specification of treated gas, is your plant is controling the H2S contents or you are getting offspec gas, why you are in a way to increase the solution strength?

Regards,
Anjum Aziz