Abnormal operation of the hydrogen sulfide stripping tower in the diesel-oil mixed hydrogenation unit led to unsatisfactory copper sheet corrosion levels in the refined naphtha
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Abnormal operation of the hydrogen sulfide stripping tower in the diesel-oil mixed hydrogenation unit caused the copper strips used in refining naphtha to suffer from corrosion that rendered them unsuitable; however, the tests conducted by the experts showed that the organic sulfur content met the quality requirements, while the inorganic sulfur content was above the specified limits. Upon inspection, it was found that: 1. The superheating temperature of the stripping steam does not meet the design requirements ； 2. The stripping steam pressure is too low, resulting in difficulty in injection and poor stripping efficiency. Solution: 1. Increase the stripping steam temperature to the design value ； 2. Increase the steam pressure so that it is higher than the operating pressure of the stripping tower. Additionally, increase the feed temperature of the stripping tower appropriately. Please, fellow sailors, discuss whether there are any other parameters that need to be adjusted in addition to those mentioned above
You can try reducing the pressure in the stripping tower
Thank you! Does a decrease in the pressure of the stripping tower have a significant impact on desulfurization? What is the minimum value, in MPa?
You control 0.7MPa, give it a try. Our unit is currently at 0.85 MPa in terms of steam pressure, while the stripping tower is temporarily set at 0.7 MPa; all quality parameters are within acceptable limits!
Thank you! The external steam pressure here is only 0.75 MPa. Under normal circumstances, to meet the requirements for stripping, it is appropriate to keep the pressure in the stripping tower between 0.6 and 0.65 MPa. This pressure differs significantly from the design value of 0.9 MPa; I’m not sure if this will have a significant impact on operations or quality, but I’ll have to give it a try
It depends on the pressure in your stripping tower; generally, a reduction of 0.1 Mpa is sufficient
Has this adjustment method been tested on your device? How much control before and after pressure? Is the effect noticeable? Thank you!
Could you explain it in detail? Thank you
In fact, the stripping tower is primarily used to remove hydrogen sulfide and certain light components, ensuring that the sulfur content and vapor pressure of the naphtha are within acceptable limits. We keep the tower pressure at 0.6 MPa; the quality is satisfactory, and it also helps to save energy.
It is also necessary to check the changes in the feed temperature of the hydrogen sulfide stripping tower, as well as the changes in the sulfur content level of the crude oil.
The cold low-pressure gas is redirected to the flare; the line leading to the tower for light hydrocarbons is reduced in size, resulting in an increase in the amount of sulfur-containing dry gas