There is a lot of foam in the amine solution
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Carbon dioxide is being removed using MDEA. At present, there is a lot of foam in the rich liquid, and its carbon dioxide content is high. The temperature of the gas entering the absorption tower is 12 degrees, while the temperature of the lean liquid is 40 degrees. Today, some of the amine solution was taken out, and a layer of floating oil was found on its surface. What is the reason for the excessive foam? and treatment measures
I’ll roughly explain the process; with such incomplete information, it’s impossible to make a judgment.
Based on the phenomena you described, oil content in the amine solution is a major cause of foaming. Does your reboiler use heat transfer oil or steam? The feed gas contains oil or has a high level of impurities. Is the water-resistant activated carbon at the outlet of the lean liquid pump installed?
The reboiler uses heat transfer oil, and no activated carbon filter is installed
Check if there is any leakage in the heat transfer oil of the reboiler Generally, a certain amount of fluid at the outlet of the lean liquid pump passes through water-resistant activated carbon for filtration and adsorption before entering the pump inlet. Water-resistant activated carbon absorbs oil and heavy hydrocarbon impurities from solutions, preventing their accumulation.
Have the composition components of your feed gas changed? Still managing gas pipeline transportation? Now some property owners like to steal some associated gas from oil fields for use; the high oil content in such gas can easily cause foaming ； Secondly, in terms of process parameters, the inlet gas temperature is 12°C while that of the lean liquid is 40°C, resulting in a temperature difference of nearly 28°C; this leads to oil precipitation in the gas phase, which is also a cause of foaming ； Finally, poor temperature control in the regeneration section can also lead to foaming as a result of amine solution degradation ； Solution: Install additional liquid-rich mechanical filters and activated carbon filters ； Increase the amount of defoamer and observe the pressure drop in the absorption tower ； Finally, increase the temperature of the natural gas entering the tower to ensure that the temperature difference between the gaseous phase entering the tower and the temperature of the lean liquid entering the tower is ≤15℃
There is too much oil in the amine solution; the temperature of the natural gas entering the tower is too low. Raising the temperature in the regeneration tower increases the amount of oil that evaporates, which in turn leads to an increase in the load on the filtration units
There is a significant temperature difference between natural gas and the amine solution; therefore, a carbon filter and a dust filter should be added
Which company’s activated carbon is used in the bypass filtration system at the outlet of the lean liquid pump? What specifications?
I agree with you; try adding some defoamer.
The amine solution system is equivalent to a closed-loop system; will the heavy components gradually accumulate? If there is a foam layer, can’t an antifoaming agent be used either? Beginners, please give me some advice