Blackness of catalytic cracking distillate diesel
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Hello everyone. I am an ordinary operator involved in catalytic cracking and distillation processes. I’m facing a problem that I can’t solve at the moment. Our plant has a processing capacity of 200,000 tons per day; it has just completed its major repair and has resumed operations. Currently, the catalytic diesel produced has a dark color, but its flash point, freezing point, and the temperatures at various distillation outlets are all within normal ranges. This issue has persisted for two days now, and no solution has been found yet. I hope that experienced professionals can offer some advice
Take a sample from the pump to check if the color is still black.
Do you mean it turns black in color, but the product still passes the tests?
Check whether there is a heat exchanger for heat exchange between diesel and heavy oil, and verify if the heat exchanger is leaking
Check whether there is a leak in the middle section, and also take a look at the heat exchanger for the raw material in the top circulation path
Check the glass level gauge in the stripping tower to see if its color is clear and transparent
If it is a leak in the heavy oil heat exchanger, changes should be identifiable from the diesel flow process
Has the nature of your raw materials changed? The feed to your equipment is likely to be quite mixed; please analyze whether there has been any change in the properties of the raw materials
It’s possible that too much freshing agent was added at the start of the process, resulting in higher activity and a greater degree of reaction; it is recommended to try reducing the catalyst’s activity.
Is it still black after taking it out, or does it turn black after being left there? The unsaturated hydrocarbons increase when accelerated; it turns black after just one day