How to prevent excessive increases in system pressure difference in gasoline hydrogenation
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In gasoline hydroprocessing units, due to the high content of olefins, dienes, gums, sulfur, and nitrogen in gasoline, condensation reactions occur during the hydrogenation process, leading to coking in the high-pressure heat exchangers and at the top of the reactors. This results in a rapid increase in pressure difference, forcing the unit to shut down for maintenance. How to avoid a rapid increase in pressure difference during operation?
We use direct feeding via the unit, with material coming in from upstream units without passing through a tank area to minimize exposure to air. Prevents the oxidation of dienes. It works very well. Additionally, a portion of the refined oil is returned to the raw material tank. Reduce the olefin content under condition two.
Solution: 1. Use upstream units to supply materials directly to the gasoline hydrogenation unit, thereby reducing intermediate steps; the raw material tanks should be sealed with nitrogen or gas； 2. Install a filter screen on the feed pump to prevent gums from entering the heat exchanger ； 3. Choose a high-power circulator whenever possible to increase the hydrogen-to-oil ratio ； 4. Install a steam injection point ahead of the heat exchanger near the raw materials; if necessary, inject some steam to reduce the system pressure drop.