How to address the thermally stable salts in the lean liquid

For this type of substance, regular handling and analysis are very important; one needs to pay attention when its level is low, and only start looking for solutions when it rises too high... The usual approach is to use defoamers to alleviate the effects of salt presence, and it’s best to employ filtration devices designed for heat-stable salts.

Temporarily, a professional purification company can be hired to purify the amine solution, and one can find a way to install another set of purification equipment on their own

There is a heat-stable salt treatment system, complete set of equipment

Add an amine solution purification system to remove excess thermally stable salts

What exactly is a thermostable salt?

The relatively weak salts formed between H, S, CO2 and the amine solution can be decomposed under heating conditions, allowing for regeneration through heat. In contrast, thermostable salts are those that are produced when the amine solution reacts with the acidic components in the feed gas (such as formic acid, oxalic acid, acetic acid, etc.) as well as oxygen during the desulfurization process, resulting in the formation of formates, oxalates, acetates, sulfates, chlorides, etc. Generally, these salts cannot be separated out in a regeneration tower by changing temperature; hence they are referred to as thermostable salts. The hazards of thermal steady-state salts include increased equipment corrosion, reduced desulfurization efficiency due to amine solution foaming, and increased amine solution consumption. The pathways for the formation of thermostable salts generally involve the following aspects: the absorption of strong anions by amines ； H: The elemental sulfur in the oxide of S reacts with amines under heating conditions to form compounds ； Oxidative degradation of amines and reaction of acidic components in the feed gas with the amine solution ； The operation of the device for treating sulfur exhaust gas by the amine method results in the formation of SO2, which then comes into contact with the amine solution to form thermally stable salts. The reason why thermostable salts accelerate equipment corrosion is that the anions of these salts react with the ferrous sulfide protective layer on the equipment, causing the metal surface to remain exposed to a corrosive environment and thus accelerating corrosion. The increase in corrosives and impurities is a significant factor contributing to foaming in the amine solution; severe foaming reduces the efficiency of contact between the amine solution and the feed gas, thereby lowering the quality of desulfurization. On the other hand, the increase in the content of thermostable salts in the amine solution comes at the expense of the effective concentration of the amine solution. The process of removing thermostable salts using AmiPur technology also involves releasing the amine contained within those salts, so that it can be reused for absorbing H2S and CO2, thereby improving the desulfurization efficiency.

Is this also the reason for the severe corrosion in our lean liquid pipelines at temperatures above 60 degrees Celsius? But our stable salt level isn’t high either; it’s just that the amine solution foams a lot?