Note on the corrosion inhibitor issue
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We inject a corrosion inhibitor at the top of the fractionation tower in our catalytic cracking unit; it is added to the oil and gas pipeline in the fractionation tower after mixing with acidic water. Is the acidic water used for dilution? Our corrosion inhibitors are already prepared; I really can’t understand why this doesn’t increase the cooling load on the oil and gas system Please give some guidance
After adding the corrosion inhibitor, in order to prevent scaling caused by ammonium salts, do you use acidic water to dissolve and dilute them?
Note that corrosion inhibitors are primarily used to form a protective layer on the metal surface in order to reduce equipment corrosion. Note: Acidic water is used to dissolve ammonium salt scaling; the two are not related. The corrosion inhibitor is injected at room temperature, so there is no issue of increasing the cooling load.
Reply to 3# lyybjgz: The amount of corrosion inhibitor used is very small. With such a large oil and gas system, can it dilute all the ammonium salts?
Some raw materials contain a small amount of chlorine; although the amount is low, given the large volume of crude oil processed, the amount of chlorine eventually accumulates. After ammonia is added, ammonia ions combine with chloride ions to form salts; ammonium chloride crystallizes easily, even at water temperatures of 80–90°C. Note: Acidic water is used to wash away salts, preventing salt crystals from clogging the tube bundles.
Ammonia is not injected at the top of our distillation column, so there is no risk of ammonium salts forming and blocking the tube bundles. If ammonia is not injected, does that mean it’s not necessary to inject acidic water either?
Reply to 5# 276957697: Injecting acidic water is not just for washing out salts, right? If we don’t inject ammonia at the top of the tower, there’s no risk of crystallization blocking the tube bundles. Could we consider stopping the use of acidic water?
Isn’t the role of corrosion inhibitors mainly to prevent corrosion in the oil and gas pipelines at the tower top? But isn’t the vent gas system protected by a layer of iron sulfide?