I' am working as Process engineer working in Natural Gas Treatment facility.
Recently, on of the Amine Absorption columns in our plant is behaving strangely as temperature on tray 5 & 6 is fluctuating while other trays are stable.
This column is a low pressure (160psig) column, using floating valve trays. As we have 21 Trays from top to bottom of the column and we managed to monitor temperature fluctuation across the column. It is very strange that temperature is fluctuating only on tray 5 & 6 and remaining trays are stable.
A few points to highlight which we already worked on but still problem is there.
1. Fluctuation in feed gas H2S and CO2 concentration: Feed gas composition in terms of H2S and CO2 remained constant and as such will not cause any fluctuation during the absorption process.
2. Fluctuation in the lean DGA flow control valve output: Both lean DGA flow control valve and tray 6 temperature indicator control tuning were checked by control engineer and retuning done for the temperature control.
3.Faulty flow and tray temperature transmitters: All related flow and temperature transmitters re-calibrated and now functioning properly.
4. Fluctuation as a results of foaming: The antifoaming system is working properly, and the foaming tendency analysis indicates no faming. Liquids hydrocarbons levels also drained from the inlet separators to ensure that no hydrocarbons carry over occurs.
5.Contactor differential Pressure: The contactor differential pressure is well with in the recommended limits.
If anyone have opinion the cause of this strange phenomenon for temperature fluctuation only on tray 5 & 6., please share with me.
thank you so much.