【Q&A Question 027】2017.01.27
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This post was last edited by 955559 on 2017-7-21 at 12:38. [Q&A Question No. 027] Why is demineralized water injected into the hydrogenation reaction system before high-pressure air cooling? 2017.01.27 The reference answers will be visible after responding; points are awarded by identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) The products of the hydrorefining reaction contain certain amounts of gases such as ammonia, hydrogen sulfide, and carbon dioxide. At certain low temperatures, these substances react to form solid crystals, which deposit in the tubes of air-cooled heat exchangers and other types of heat exchangers. This not only reduces the heat transfer efficiency of these devices but also leads to an increase in pressure drop; in severe cases, it can even block the tubes, causing the equipment to stop functioning. Therefore, it is necessary to inject demineralized water into the reaction effluent before 170 degrees Celsius in order to wash out ammonia or hydrogen sulfide, as well as to dissolve any ammonium salts that have already crystallized. New Normal Cup – Voting for the Top 10 Members of HaiChuan in 2016 is now underway; choose the member you care about the most (please cast your valuable vote for those in the Petrochemical Division). http://bbs.hcbbs.com/thread-1667649-1-1.html Summary post of Q&A sessions from 2017 (updates available now). http://bbs.hcbbs.com/thread-1657793-1-1.html Summary post of daily questions from 2017 (updates available now). http://bbs.hcbbs.com/thread-1657794-1-1.html Summary post of Q&A sessions from 2016 (all updates completed). http://bbs.hcbbs.com/thread-1597792-1-1.html Third round of selection for outstanding management members at HaiChuan. http://bbs.hcbbs.com/thread-1655902-1-1.html “Creative Ideas for Energy Saving” campaign in the Petrochemical Division. http://bbs.hcbbs.com/thread-1666758-1-1.html Xiaomi phones available for winners. Summary post collecting chemical industry technical materials from the “Petrochemical Section”. http://bbs.hcbbs.com/thread-1654603-1-1.html Many prizes waiting for winners (Source: HaiChuan Chemical Forum)
It prevents ammonium salts from forming solid crystals at low temperatures and depositing in the tubes of air-cooled heat exchangers and other types of heat exchangers, which not only reduces the heat transfer efficiency of these cooling devices but also leads to an increase in pressure drop.
The products of the hydrorefining reaction contain certain amounts of gases such as ammonia, hydrogen sulfide, and carbon dioxide. At certain low temperatures, these substances form solid crystals that deposit in the air-cooled heat exchangers and other heat exchange tubes. This not only reduces the heat transfer efficiency of the heat exchange equipment but also increases pressure drops; in severe cases, it can block the tubes of the cooling equipment, leading to the shutdown of the plant. Therefore, it is necessary to inject demineralized water into the reaction effluent before 170°C in order to wash out ammonia or hydrogen sulfide, or to dissolve any already crystallized ammonium salts. Based on the temperature drop characteristics of the plant’s process flow, the water injection point is usually located before the high-pressure air coolers.
The reaction products contain certain amounts of gases such as ammonia, hydrogen sulfide, and carbon dioxide. At certain low temperatures, these substances react to form solid crystals, which deposit within the tubes of air-cooled heat exchangers and other types of heat exchangers. This not only reduces the heat exchange efficiency of these devices but also increases pressure losses; in severe cases, it can even lead to tube blockages. Deionized water is injected into the reaction effluent before 170°C to wash the reaction effluent. Based on the temperature drop characteristics of the plant process, the water injection point is generally located before the air-cooled high-pressure air cooler.
Prevent ammonium salt crystals from clogging the air-cooling tube bundles
Prevent ammonium salts from crystallizing and blocking pipes.
There is blockage caused by ammonia salt crystals; water injection is used to prevent this blockage
The products of the hydrorefining reaction contain certain amounts of gases such as ammonia, hydrogen sulfide, and carbon dioxide. At certain low temperatures, these substances react to form solid crystals, which deposit in the tubes of air-cooled heat exchangers and other heat exchangers. This reduces the heat transfer capacity of these cooling devices, leads to an increase in pressure drop, and in severe cases can cause the tubes to become blocked, resulting in the shutdown of the plant. To remove ammonia or hydrogen sulfide, or to dissolve any already crystallized ammonium salts, demineralized water is injected into the reaction effluent before 170°C for washing purposes. Depending on the temperature profile along the plant’s process flow, the water injection point is usually located before the high-pressure air cooling stage.