【Q&A Question 128】2017.05.08
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This post was last edited by 955559 on 2017-7-21 22:59. [Q&A Question 128] 2017.05.08: What should be noted during the normal operation of a reactor as well as during its startup and shutdown? 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) During normal operation, it is necessary to monitor the pressure and temperature of the reactor bed in order to assess the equipment’s performance; exceeding the specified temperature and pressure limits is strictly prohibited to protect the equipment and the catalyst. (2) During startup and shutdown, the rate of temperature increase, as well as the rate of pressure change, should be strictly controlled to avoid uneven temperature distribution within the equipment and its components, which could lead to significant thermal stresses. (3) To prevent sulfide stress corrosion cracking in austenitic stainless steel components, the formation of polythiic acids should be suppressed during shutdown. (4) When shutting down, a scheme should be adopted to fully release the hydrogen energy stored in the operating state. For example, lower the pressure first, then reduce the temperature. (5) During startup and shutdown, efforts should be made to avoid the presence of liquid water and oxygen in the reactor. Scoring criteria: 2 Wealth points for incorrect attempts; 3–8 points for *incomplete* answers. 10 Wealth points for correct answers, provided with a detailed explanation; 15–20 Wealth points if the answer is correct but lacks sufficient details. Please score according to these criteria. 2017 Q&A Summary Thread (updating now) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updating now) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (already updated) http://bbs.hcbbs.com/thread-1597792-1-1.html
(1) During normal operation, it is necessary to monitor the pressure drop and temperature of the reactor bed in order to assess the equipment’s performance. Exceeding the specified temperature and pressure limits is strictly prohibited to protect the equipment and the catalyst. (2) During startup and shutdown, the rate of temperature and pressure changes must be strictly controlled to avoid uneven temperature distribution within the vessel and its components, which could lead to significant thermal stresses. (3) To prevent sulfide stress corrosion cracking in austenitic stainless steel components, the formation of polysulfates should be suppressed during shutdown, or alkaline solutions should be used to neutralize these corrosion products when they form. (4) When shutting down, measures should be taken to fully release the hydrogen energy stored during operation. For example, lower the pressure first, then reduce the temperature. (5) During startup and shutdown, efforts should be made to avoid the presence of liquid water and oxygen in the reactor.
Temperature, pressure, hydrogen-to-oil ratio, space velocity
Pay attention to the rate of temperature increase, temperature decrease, and the reaction
During normal operation, it is necessary to monitor the bed temperature and temperature rise as well as the pressure drop, in order to prevent overheating and overpressure; operations should be carried out smoothly； During startup and shutdown, it is necessary to follow the principle of increasing the volume first when raising the temperature, and reducing the volume first when lowering the temperature; the rate of temperature change must be controlled to prevent overheating
(1) During normal operation, it is necessary to monitor the pressure drop and temperature of the reactor bed in order to assess the equipment’s performance. Exceeding the specified temperature and pressure limits is strictly prohibited to protect the equipment and the catalyst. (2) During startup and shutdown, the rate of temperature and pressure changes must be strictly controlled to avoid uneven temperature distribution within the vessel and its components, which could lead to significant thermal stresses. (3) To prevent sulfide stress corrosion cracking in austenitic stainless steel components, the formation of polysulfates should be suppressed during shutdown, or alkaline solutions should be used to neutralize these corrosion products when they form. (4) When shutting down, measures should be taken to fully release the hydrogen energy stored during operation. For example, lower the pressure first, then reduce the temperature. (5) During startup and shutdown, efforts should be made to avoid the presence of liquid water and oxygen in the reactor.
(1) During normal operation, it is necessary to pay attention to the pressure drop and temperature of the reactor bed in order to assess the operating condition of the equipment; exceeding the specified temperature and pressure limits is strictly prohibited to protect the equipment and catalyst. (2) During startup and shutdown, the rate of temperature and pressure changes must be strictly controlled to avoid uneven temperature distribution within the unit and its components, which could lead to significant thermal stresses. (3) To prevent sulfide stress corrosion cracking in austenitic stainless steel components, the formation of polysulfates should be suppressed during shutdown, or alkaline solutions should be used to neutralize these corrosion products once they form. (4) When shutting down, measures should be taken to fully release the hydrogen energy stored during operation. For example, reduce the pressure first, then lower the temperature. (5) During startup and shutdown, efforts should be made to avoid the presence of liquid water and oxygen in the reactor.
(1) During normal operation, it is necessary to monitor the pressure drop and temperature of the reactor bed in order to assess the equipment’s performance. Exceeding the specified temperature and pressure limits is strictly prohibited to protect the equipment and the catalyst. (2) During startup and shutdown, the rate of temperature and pressure changes must be strictly controlled to avoid uneven temperature distribution within the vessel and its components, which could lead to significant thermal stresses. (3) To prevent sulfide stress corrosion cracking in austenitic stainless steel components, the formation of polysulfates should be suppressed during shutdown, or alkaline solutions should be used to neutralize these corrosion products when they form. (4) When shutting down, measures should be taken to fully release the hydrogen energy stored during operation. For example, lower the pressure first, then reduce the temperature. (5) During startup and shutdown, efforts should be made to avoid the presence of liquid water and oxygen in the reactor.
(1) During normal operation, it is necessary to monitor the pressure drop and temperature of the reactor bed in order to assess the equipment’s performance. Exceeding the specified temperature and pressure limits is strictly prohibited to protect the equipment and the catalyst. (2) During startup and shutdown, the rate of temperature and pressure changes must be strictly controlled to avoid uneven temperature distribution within the vessel and its components, which could lead to significant thermal stresses. (3) To prevent sulfide stress corrosion cracking in austenitic stainless steel components, the formation of polysulfates should be suppressed during shutdown, or alkaline solutions should be used to neutralize these corrosion products when they form. (4) When shutting down, measures should be taken to fully release the hydrogen energy stored during operation. For example, lower the pressure first, then reduce the temperature. (5) During startup and shutdown, efforts should be made to avoid the presence of liquid water and oxygen in the reactor.