Water in the stabilizer tower issue

If the level of acidic water in the oil-gas separation vessel at the top of the fractionation tower is too high, or if the moisture generated by the reactions is not properly settled, this water will end up in the absorption and stabilization section. There, it is heated in the reboiler at the bottom of the stripping tower, after which it turns into gas and enters the stabilization tower. This poses difficulties for the operation of the absorption and stabilization section, affects the pressure in the stabilization tower, and results in a reduced yield of liquid hydrocarbons.

Check which stages come into contact with water or whether the water that needs to be separated has not been separated. Check whether there are any issues with the corresponding equipment structure or process design that require improvement.

The correct procedures for dealing with water in the stabilizer tower: http://bbs.hcbbs.com/thread-342088-1-1.html. If water is present in the feed to the stabilizer tower, it is necessary to start by checking the previous stages in the process: water in the feed to the desorption tower, or leaks in the intermediate circulation cooler of the desorption tower; high water level in the condensate oil tank or malfunctioning water level gauges; leaks in the intermediate cooler of the compressor; water in the vapor-liquid separator at the top of the distillation tower, which in turn causes water to appear in the feed to the absorption tower, and so on. When there is water in the stabilizer tower, its vaporization absorbs heat, resulting in a decrease in the temperature at the bottom of the tower. The hot steam generated by this vaporization rises to the top of the tower, causing the temperature there to increase. Water vapor is condensed at the top of the tower and absorbs heat at the bottom; this cycle repeats, preventing the temperature at the bottom of the tower from being stabilized and stopping the temperature at the top from dropping. Such instability in temperature and pressure naturally affects the quality of the liquefied gas. The methods outlined in the post titled “Correct Procedures for Handling Water in the Stabilization Tower” are as follows: 1. Lower the temperature at the bottom of the tower to below 100 degrees to allow for static dehydration; 2. Increase the amount of heat removed from the bottom of the tower and appropriately reduce the reflux at the top, thereby pushing the water vapor upward toward the reflux tank. Our factory has used both methods; however, the post does not provide an answer as to which method is better or more cost-effective. I’ll wait to see what others have to say~~~~~~~~

It is caused by a failure in the level control of the separator, or by water present in the liquefied gas buffer tank

Poor separation performance of the oil-gas separator in the fractionation tower or a malfunction in the level control mechanism can result in water contamination in the crude gasoline. A malfunction in the level control mechanism of the oil-gas separator in the second condensate oil unit, or other factors, can also lead to water contamination in the condensate oil, and these are the main reasons for water contamination in the absorbed and stabilized products. However, there is more or less water carryover during absorption and stabilization, and this needs to be done on a regular basis every day. Another important aspect is to ensure proper dehydration in the middle section of the desorption tower; this not only reduces water carryover but also saves heating steam used in the desorption tower. By carrying out these tasks properly, significant water carryover during absorption and stabilization can be avoided. Cooling and dehydration may cause liquefied gas to mix into gasoline, resulting in high pressure in subsequent systems.

In winter, when filling our equipment with liquid hydrocarbons, it is required to drain the liquid first; I’m not sure if this is necessary

Check in reverse order according to the process sequence to see if the level of the water separation pack at that location is too high. The liquid level in the water separation package is generally controlled between 40-60%

Reason for water carryover: 1. High water injection volume in the rich gas stream. 2. The level gauge of the storage buffer tank at the compressor outlet is malfunctioning and showing a too-high value. 3. Leak in the water cooler at the top of the stabilizer. 4. Failure of the level gauge for the stabilizer overhead reflux tank. Once the cause is identified, it’s easy to deal with.