Amine Solution Purification

By 1 September 2016

Due to side reactions and/or degradation, a variety of contaminants will begin to accumulate in an amine system. The method of removing these depends on the amine involved.

When MEA is used in the presence of COS and CS2, they react to form heat-stable salts. Therefore, MEA systems usually include a reclaimer, The reclaimer is a kettle-type reboiler operating on a small side stream of lean solution. The temperature in the reclaimer is maintained such that the water and MEA boil to the overhead and are piped back to the stripper, The heat-stable salts remain in the reclaimer until the reclaimer is full, Then the reclaimer is shut-in and dumped to a waste disposal. Thus, the impurities are removed but the MEA bonded to the salts is also lost.

For DEA systems a reclaimer is not required because the reactions with COS and CS2 are reversed in the stripper. The small amount of degradation products from COo can be removed by a carbon filter on a side stream of lean solution.