Regarding the dosage of corrosion inhibitors in hydrogenation units, and the issue of the injection location
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1. Location for adding the corrosion inhibitor: Before the air cooling at the top of the stripping tower. Should corrosion inhibitor be injected for the air cooling before high-pressure separation? Is it still sufficient to just fill it with water? 2. What is the basis for determining the amount to be added? What are the control criteria for iron ions in acidic water?
1. It is certain to inject water before high-pressure cracking, but corrosion inhibitors are generally not injected before high pressure. 2. Iron ion concentration: 3 ppm
We have carried out modifications before; the corrosion inhibitor is mixed with water and then sent to various injection points.
1. Corrosion inhibitors are generally injected at the tower top extraction point; adding water before high pressure is sufficient. 2. The dosage is calculated by the corrosion inhibitor manufacturer based on the feed volume, with the key criterion being that the iron ion concentration in the acidic water at the top of the tower should be ≤ 3 ppm
There are mainly two types of corrosion inhibitors for hydrogenation: one is injected at the outlet of the water injection tank and then pumped via a high-pressure pump into the high-pressure air cooler, while the other is injected at the top of the tower
1. The hydrogenation unit in our facility is fed with water before air cooling, and no corrosion inhibitor is added to the system. The iron ion concentration is not analyzed.
1. The inflation before high scores is merely for washing out salts. 2. The amount of corrosion inhibitor to be injected is determined by the change in iron ions in the interphase of the reflux tank, and it is generally controlled at 10 ppm
The corrosion inhibitor is only injected at the top of the tower; before high pressure is reached, only water is injected. The manufacturer will provide standards for the amount of corrosion inhibitor to be used; generally, iron ions should be kept at no more than 3PPm.
High-pressure air-cooled systems generally do not require the use of corrosion inhibitors, but sometimes oil quality does matter; the main criterion is the iron ions in the water in such systems!
Our corrosion inhibitor is added to the top of the main stripping tower and the top of the butane removal tower, at a dosage of 5-15PPM