CO2 removal solution

ahmadkakhki
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CO2 removal solution

Post by ahmadkakhki » Mon Jan 27, 2020 5:24 pm

we are using Benfield solution with DEA as activator in CO2 removal section. there are problems like foaming, H2 slip from regenerator, DEA degradation, CO2 carry over from absorber cause increasing methanator effluent temprature.
is there any experience of replacing HPC with other solution or just changing activator of Benfield solution?

BhupenMehta
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Re: CO2 removal solution

Post by BhupenMehta » Tue Jan 28, 2020 4:16 am

You may evaluate the option of activated MDEA to overcome the above operating limitations.

Ahmedahmed
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Re: CO2 removal solution

Post by Ahmedahmed » Mon Feb 03, 2020 10:36 am

About my experience with MDEACheck Concentration of MDEA and activator if concentration less than 37% (MDEA) +(3to4%activator)see this problems

BhupenMehta
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Re: CO2 removal solution

Post by BhupenMehta » Tue Feb 04, 2020 2:37 am

Yes, MDEA + Activator conc. shall be maintained as per OEM recommendation and as per system design, but make-up rate of solution is quite low,

bedmonds
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Re: CO2 removal solution

Post by bedmonds » Tue Feb 11, 2020 11:17 pm

Hi Ahmad, No experience with a change to MDEA and I know it can be beneficial for a lean/semi-lean Benfield unit but I think the attractiveness disppears if single stage, lean only regeneration. For Benfield act-1 is a nice option and UOP can advise-it is more stable but does require effective waterwash due to higher volatility
For
foaming-might be worth trying a soilicone based defoamer (SAG 10)
losses-if the plant is being pushed hard carryover into the waterwash section and tray fouling plus tray jet entrainment can be a problem-there are good solutions including chevron elements below WW trays and going to maxime ballast units (valves) per tray with pipe type downcomers
H2 carryover can be helped with silicone based defoamer or higher absorber level - also could be Benfield steam generator tube leak

naseemce
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Re: CO2 removal solution

Post by naseemce » Thu Feb 13, 2020 7:15 pm

aMDEA is best option from consumption , CO2 slippage and energy point of view and now all modern plants are running it . Most of the plants are using SAG and Amyrol solution to dissociate foaming however 1st find the foaming source which could be
1- salts and iron
2- oil or hydrocarbons
3- ineffectiveness of solution.

ahmadkakhki
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Re: CO2 removal solution

Post by ahmadkakhki » Fri Feb 14, 2020 9:39 am

thank you,
actually which consideration must be taken into accouunt for changing total solution from HPC to MDEA?
our plant is useing both lean and semi lean solution now.

BhupenMehta
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Re: CO2 removal solution

Post by BhupenMehta » Sat Feb 15, 2020 2:40 am

Consideration for change over from HPC to MDEA may be
-regeneration energy requirement
-CO2 slip from absorber
-CO2 product purity
-solution flow rate/pumping energy
-solution make-up rate
-spent solution disposal

zeeshan
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Re: CO2 removal solution

Post by zeeshan » Sat Jul 25, 2020 8:02 am

Dear Sir,

Do you have experience of flushing of whole MDEA system (vessels and lines) with castic soda solution (05% W/W) on Haldor Topsoee plants for removal of corrosion products and scale removal inside the system?

Best Regards,

M Zeeshan Shoaib
FFC, Pakistan

Zubairtalha
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Re: CO2 removal solution

Post by Zubairtalha » Tue Jul 28, 2020 1:49 pm

Hi,
Mentioned problems ("foaming, H2 slip from regenerator, DEA degradation, CO2 carry over") could appear in any solution. How you monitor and remove degradation products from system? Activated carbon filtration?

Foaming: Degradation products, Iron, SS, Salts etc. Shake test for foaming can indicate solution foaming tendency. Color Index and these impurities level could be checked.
H2 Slip: many causes like Over circulation of solution, Foaming in Absorber, Leakage in reboilers etc.
Dea Degradation: Reboiler temperatures and Passivation air flow rates could be checked.

Regards;
Zubair Talha

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