Have you ever seen a atmospheric pressure tower that has corroded to this extent?
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This post was last edited by LQ198619 on 2017-7-23 at 17:12. It shows the internal corrosion condition of the upper part of the atmospheric tower, taken during the last shutdown for maintenance. Since it was photographed with a smartphone, the image is not very clear. Please take a look first, and then we will analyze the reasons behind such severe corrosion. Let’s first talk about the changes in operating conditions before the shutdown. It’s been over a year since the last shutdown, so I can’t remember exactly what happened. I recall that the top circulation system of the entire atmospheric tower was no longer functional, as the oil collection tank at the top had corroded, and the two upper layers of trays in the tower had collapsed as well. It was impossible to control the quality of the gasoline produced at the top. But the managers in our workshop were really clever; they came up with a way to adjust the gasoline distillation range so that it met the required standards, even without a top circulation system. This allowed us to keep the plant operational until the scheduled maintenance period, which lasted around a month. During maintenance, we analyzed the reasons for such severe corrosion; the main cause is the high sulfur content in the crude oil used in production, which is usually above 1.5%. Let’s discuss what methods we use to adjust the gasoline boiling range Are there other factors besides sulfur content that contribute to such severe corrosion? http://down.hcbbs.cc/attachment/forum/201706/10/203353z7y06fdo70r6eod0.jpg Petrochemical area—New ideas for energy savings: the “Creative Ideas” campaign (the second phase is currently in full swing). http://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1666758 (Source: Haichuan Chemical Industry Forum) 2017: “My Technical Upgrades” in the coal chemical industry. http://bbs.hcbbs.com/thread-1786290-1-1.html (Source: Haichuan Chemical Industry Forum website) First round of voting for the best e-books on Haichuan Forum—Chance to win prizes by voting (for members of the Management and Technology group and those in grade 5 or above). http://bbs.hcbbs.com/thread-1799455-1-1.html (Source: Haichuan Chemical Industry Forum website)
Although I don’t know the specific details behind it, it seems that the corrosion is indeed quite severe
The facility now needs to be adapted through modifications, with material upgrades to handle high-sulfur and high-acid crude oils. Otherwise, there will be endless troubles!
1: The main reasons are an increase in sulfur content or erosion, both of which can cause corrosion of the equipment. 2: Secondly, the material grade of the equipment is also crucial, as most of the volatile small molecules formed during oil distillation accumulate at the top. Trace amounts of water, HCL, and small organic acids that condense as temperature drops can cause corrosion to the equipment. 3: If tower top reflux is not available, cold reflux can be used as a substitute.
Don’t you have an electrodialysis system? At least carry out raw material pretreatment; it will be better for the equipment!