Service life of amine solution
Thread Content
For the decarburization process in the LNG plant, an amine solution (methyldiethanolamine) is used at a concentration of around 45%. The system was put into service at the end of 2014. Currently, the amine solution has turned yellowish in color, and its ability to remove carbon dioxide has decreased compared to before (there is an online CO2 detector at the decarburization outlet). Is there any specified service life for this amine solution? How many years does it take to need a complete replacement?
Yes, after absorbing carbon dioxide, the carbon dioxide content in natural gas is below 50 ppm
As far as I know, after releasing the absorbed carbon dioxide, it can regain its original absorption capacity
There is no specific shelf life specified for amine solutions; it is generally determined based on the effectiveness of treatment. I’m not sure if you have any on-line or off-line equipment for purifying amine solutions. If you do, you can enhance the purification process; if not, you can seek out companies specialized in amine solution purification. It is likely that such solutions will need to be treated after being used for an extended period of time. In most cases, it’s the amine solution that is depleted, so some fresh solution is added; if the conditions permit, the entire solution should be replaced rather than just half of it, as that could affect the effectiveness of the fresh solution. If the decarburization effect is poor, and there are no operational issues with the system nor any noticeable corrosion, it may be worth trying to reduce the solution concentration and increase the circulation rate to see if this yields better results. If the solution is purified and regenerated, and the concentration decreases as well as the circulation rate increases, but it still doesn’t work, then consider replacing it at that time