Why is demineralized water injected into the reaction system of the hydrogenation unit?
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Why is demineralized water injected into the reaction system of the hydrogenation unit? Thank you.
Demineralized water has had the calcium and magnesium ions removed, which protects equipment from scaling and has no impact on the quality of oil products
This is because hydrogen sulfide, hydrogen chloride, and ammonia are generated during the reaction process; hydrogen sulfide and ammonia combine to form ammonium hydrosulfide, while hydrogen chloride and ammonia form ammonium chloride. Both of these are ammonium salts that can clog the high-pressure heat exchangers and air coolers. To prevent this from happening, demineralized water is generally injected before air cooling; in some systems, water is injected indirectly before the second high-pressure exchanger.
Dilute the ammonium salts to prevent their crystallization from blocking air coolers, water coolers, and pipes.
During the reaction process in the hydrorefining unit, hydrogen sulfide, trace amounts of water, hydrogen chloride, and ammonia are generated, which then combine to form ammonium hydrosulfide and ammonium chloride. These two types of ammonium salts tend to crystallize more easily at temperatures between 35 and 45 degrees. To prevent blockages in the high-pressure heat exchangers and air coolers, desalinated water is injected before the high-pressure air cooler, while water is injected at the second heat exchanger after the reactor, thereby dissolving the ammonium salts and preventing crystallization, which in turn facilitates the proper operation of the air coolers.
Why is softened water injected during hydrogenation? Answer: Softened water is injected to wash away the NH3 and H2S produced in the hydrogenation reaction, and to prevent the formation of polysulfide amines or other ammonium salts (including ammonium sulfide, ammonium chloride, and ammonium carbonate), which can cause crystal formation at low temperatures and lead to blockages in heat exchangers and pipes. Such blockages can result in equipment failures and an increase in system differential pressure; therefore, softened water is used to dissolve these ammonium salts.
Prevent ammonium salt crystals from clogging the air cooler.
Wash away the ammonium salts from the air coolers and pipes. Prevent an increase in voltage drop