【Q&A Question 023】2017.01.23
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This post was last edited by 955559 on 2017-7-21 at 12:43. [Q&A Question No. 023] 2017.01.23: How to prevent coking of the catalysts in hydrogenation units during normal operation? 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.) 1. Control parameters such as the density, dry point, and color of the raw materials to prevent the introduction of large amounts of gums and asphaltenes. 2. Operate at a high hydrogen-to-oil ratio to suppress coking reactions. 3. Prevent the catalyst from overheating. Voting for the 2016 HaiChuan Top 10 Members is now underway – vote for the member you consider the most outstanding (please cast your valuable vote for those in the petrochemical sector): http://bbs.hcbbs.com/thread-1667649-1-1.html. Summary thread of Q&A questions for 2017 (updates available): http://bbs.hcbbs.com/thread-1657793-1-1.html. Summary thread of daily questions for 2017 (updates available): http://bbs.hcbbs.com/thread-1657794-1-1.html. Summary thread of Q&A questions from 2016 (already updated): http://bbs.hcbbs.com/thread-1597792-1-1.html. Third-phase selection of outstanding management members in HaiChuan: http://bbs.hcbbs.com/thread-1655902-1-1.html. “Creative Ideas for Energy Saving” activity in the petrochemical sector: http://bbs.hcbbs.com/thread-1666758-1-1.html. Xiaomi phones are up for grabs. Thread for collecting chemical engineering technical materials in the Petrochemical Section: http://bbs.hcbbs.com/thread-1654603-1-1.html. Many prizes await you (Source: HaiChuan Chemical Forum)
Ensure hydrogen purity, hydrogen partial pressure； Ensure the reaction temperature
Stabilize the feed to avoid overheating, and increase the hydrogen-to-oil ratio and hydrogen partial pressure
Avoid excessive temperature and pressure, prevent sudden changes in temperature and pressure, maintain the hydrogen-to-oil ratio, and keep the properties of the raw materials stable
Maintain a certain air velocity, maintain a certain hydrogen partial pressure, and control the reaction temperature properly
During normal production, measures are taken to prevent overheating and sudden temperature spikes, as well as other abnormal operating conditions such as low purity of circulating hydrogen, low hydrogen-to-oil ratio, low hydrogen partial pressure, and low space velocity, which could lead to catalyst coking
The main methods to prevent catalyst coking are: ① Controlling parameters such as the density, dry point, and color of the feedstock, in order to prevent the influx of large amounts of gums and asphaltenes. ②Operate at a high hydrogen-to-oil ratio to suppress coking reactions. ③Strictly prevent the catalyst from overheating.
Pay attention to changes in the properties of raw materials and make adjustments in a timely manner； The reaction temperature must be strictly controlled and must not operate above the specified limits ； Maintain an optimal hydrogen-to-oil ratio to prevent coking.
Higher hydrogen partial pressure, larger hydrogen-to-oil ratio, low-temperature operation,
①Control parameters such as the density, dry point, and color of the raw materials to prevent the excessive introduction of resins and asphaltenes. ②Operate at a high hydrogen-to-oil ratio to suppress coking reactions. ③Strictly prevent the catalyst from overheating.