Control of MDEA desulfurization regeneration loop temperature
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This post was last edited by liaifeng on 2018-9-10 at 17:26. Is it necessary to control the reflux temperature of the MDEA desulfurization regeneration stream? If control is required, what temperature should it be set at? Why control this temperature?
Optimization is carried out based on the design temperature of the regeneration tower; it is generally controlled at around 95 degrees! Neither too high nor too low is favorable for the regeneration of the amine solution!
The components at the top of the tower are mostly steam, and the temperature is affected by the tower pressure; therefore, the temperature is not controlled.
It also contains some dissolved hydrogen sulfide gas, which needs to be separated; therefore, the temperature in this section must be kept at least at 100°C!
The gas at the top of the tower contains not only water vapor but also gaseous hydrogen sulfide and amine vapor. Recirculation is achieved by using unsaturated acidic water to absorb the amine components in the gas, thereby increasing the concentration of hydrogen sulfide. Therefore, the temperature of the reflux stream is generally determined by the temperature of the medium in the recirculation tank; after being cooled by air coolers and water coolers, this temperature should not exceed 40°C, so the reflux temperature should also remain below this value.
This post was last edited by notemper on 2018-9-17 17:48
The location of the rich MDEA feed inlet is usually 4 trays below the tower top; therefore, the feed temperature of this MDEA should be as close as possible to the calculated temperature of that tray.
The recycle temperature of the regenerated slurry is essentially the same as that of the regenerated acidic gas; the temperature is generally controlled at 40 degrees. In winter, it can be increased to 60 to 80 degrees to prevent incomplete combustion of ammonium salts in the sulfur production section.
At this temperature, the water vapor content in the overhead gas is very low!!