Our plant’s desulfurization unit has been in operation for 3 months since its maintenance, and the amine solution has turned black. Could anyone tell me what might be causing this?
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Dear experts, our plant’s desulfurization unit was under maintenance, during which some fresh amine solution was added. Three months after the unit was put back into operation, we noticed that the amine solution had turned black. What could be the cause of this? The supplier speculates that the equipment was not cleaned thoroughly after maintenance, leaving rust residues that formed ferrous sulfide, causing the amine solution to turn black. Is that the reason? Please give me some **guidance!
The blackening of the amine solution is often due to the presence of metal ions in it, particularly iron ions. In your case, the supplier’s explanation is somewhat credible. If the equipment is not thoroughly cleaned during maintenance, residual rust (iron ions) may react with sulfides in the amine solution to form ferrous sulfide, thereby darkening the amine solution. It is recommended to carry out the following steps for treatment and inspection: 1. Thoroughly clean and flush the amine solution system to ensure that no metal ions remain. 2. Inspect and replace the screens and filters to prevent any unremoved rust particles from re-entering the system. 3. Analyze the amine solution sample to determine whether there are any other contaminants present. 4. In future operation and maintenance, strengthen the inspection and upkeep of the equipment to ensure its cleanliness. This helps to prevent similar problems from occurring again and ensures the proper operation of the desulfurization system. .
Okay, thank you very much to the kind person on the second floor for their reply! I’m really grateful!
Is there any residue after it turns black? It is advisable to consider conducting tests for iron ions in amine solutions. Additionally, it is necessary to check whether char or ash is introduced during the desulfurization of dry gas and gas, which could cause discoloration. It is also important to verify whether there is any contamination from dark-colored substances resulting from inadequate purging of the system; for example, it should be checked whether filters use activated carbon, whether the compressive strength of the activated carbon used meets the required standards, and whether the activated carbon in the filters might get crushed under pressure leading to discoloration, or whether it is of poor quality and has not been cleaned before being installed and put into use
Three filters are installed on the circulation pipeline to filter the amine solution (a skid-mounted design can be used when the flow rate is low), in order to address the blackening issue. It’s quite troublesome not to address process changes.
It’s a normal phenomenon; as long as it doesn’t affect the metrics, it’s fine. Keep a portion of the solution separated for filtration.
The person who spoke earlier summarized it well: one issue is the residual iron slag resulting from inadequate rinsing, and the other is the presence of glue powder or carbon powder from the upstream process. Using high-precision filters can help reduce coloration to some extent. Additionally, it’s possible to consider using special cutting fluids to activate the amine solution, which can address various problems such as solid particles and thermally stable salts in one go. If you’re interested, feel free to contact me