CO2 removal process

[Afzal Shumaila]

Hello everyone, I am Shumaila and I have to give my presentation on Benfield Solution Carryover.Actually the plant data that I got is like that they are using Benfield solution for CO2 removal and has changed the activator DEA with ACT-1 but still facing carryover problem from re-generator and absorbor so is there any modification you proposed to reduce carryover?

[Ahmed Faizan]

The solution foaming is one the major factor which contributes to solution carry over. Please check is the solution has increased numbers of foriegn particles or not. These solutions are normally filtered . May be this can help

[Edmondson Bob]

Hi Shumaila,
A few thoughts and questions:
If waterwash trays is badly fouled with Fe/V precipitate it suggests carryover of droplets from the packing below and for that situation a nice solution is to install one or more horizontal chevron elements which will remove 95% or more of the droplets
If the demister is also badly fouled it suggests jet entrainment from the waterwash trays and going to valve trays with maximum number of valves (can use pipe downcomers to increase active area). Fouling of the trays increases carryover dramatically.
For the short term, higher regenerator pressure helps due to reducing velocity of the gas phase
Ensuring side stream filter works well can help if particulates are causing fomaing
Experimenting with silicone based vs. other types of defoamers can have a significant effect on carryover and H2 concentration in CO2

[BEESHA SURESH]

The main reason for solution foaming is due to accumulated dirt, oil etc since inception. To aviod the carryover from the towers, the main reason to be eliminated. Solution to be purified by passing (10-15%) filtration flow through activated carbon filter. The fear will be leaching of activated carbon and furthur lead to caaryover agrivation. But, Johnson screens at AC filter outlet will give no leaching or carbon carryover. So, eliminate the cause and Solution carryover may automaically be solved.

[Naseem Kashif]

Carry over will happen when there is a foaming in solution caused by carbon dust. oil, Fe and salts accumulation.
Also depends on the condition of trays and packing fouling .
V/L velocity in regenerator is also important which will lead to flooding .
Design reassessment with CO2 removal system expert company like BASF will support to resolve it however fr time being handle by increasing pressure.

[Author]

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