Treatment of water in liquefied gas from delayed coking units
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In the stabilizer of our company’s delayed coking unit, water contamination in the stabilized gasoline occurs frequently. This leads to significant water content in the liquefied gas in the reflux tank at the top of the stabilizer. When this liquefied gas is used as reflux and sent back to the top of the tower, it causes substantial fluctuations in the pressure there, creating a vicious cycle that affects production. I don’t know how to get rid of this water Is there a good way to solve it?
How could the water level be so high? Could you please specify what other conditions or abnormalities are present? Or rather, what caused there to be so much water in this generation?
Because it is acidic water, sulfur-containing wastewater, and may also contain hydrocarbons. So where can it be sent?
First, the water should be drained frequently and thoroughly, with the level in the liquid separation tank being controlled at its lower limit； The reflux tank at the top of the stabilizer also needs to have its water level reduced; the level control for the liquid separation tank should be set at its lower limit, and if that isn’t sufficient, the level should be lowered to the minimum. Ensure that the return flow is free of water; it will get better over time
Control the liquid-liquid interface level of the rich gas properly； Prevent water from entering the desorption tower ； The middle part of the desorption tower should be dehydrated ； LPG tanks also need to be dehydrated, with the level carefully controlled.
I thought about it for a long time, and I believe that water in the stabilizer gasoline may be caused by water in the feed to the stabilizer tower, a low temperature at the bottom of the stabilizer tower, and high pressure at the bottom of the same tower. But in the case of liquefied gas containing water, as you mentioned, if the level of the liquefied gas tank is well controlled and sufficient separation space is provided, it is possible to avoid the presence of water in the liquefied gas. Moreover, the volume of the liquefied gas reflux (i.e., liquefied gas without water) itself can cause fluctuations in the pressure at the top of the stabilizer! When installing the equipment, I often encounter a high temperature at the top of the stabilizer; as a result, I increase the reflux of liquefied gas, which leads to a decrease in the amount of liquefied gas leaving the equipment. When the reflux of liquefied gas reaches a certain level, the temperature and pressure at the top of the tower actually increase. You might as well take some inspiration from it; I’ll ask others when I have time.