【Daily Question No. 292】October 25, 2018
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【Daily Question No. 292】October 25, 2018: Briefly describe the key control factors that affect the degree of hydrogenation during the startup phase The factors affecting the degree of hydrogenation at various stages include: (1) Inadequate purging of the system, which results in a high pressure drop after startup; this limits the compressor’s displacement, prevents the hydrogen-to-oil ratio from meeting the required levels, and reduces the heat exchange efficiency of the heat exchange equipment, thereby hindering an increase in reaction temperature ； (2) Uneven catalyst packing leads to channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst has a low packing density; at the same volume space velocity, the weight space velocity is low, resulting in limited effective activity of the catalyst ； (3) Too rapid heating rate during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； (4) Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； (5) Without preliminary activation and stabilization, the catalyst cokes rapidly ； (6) During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, leading to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting an increase in the reaction temperature. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Correct: 3 wealth, Incorrect: 1 wealth ； Mass posting of posts – rated based on the lowest score ； Replies that are unrelated to the answer are considered spam and will be deleted immediately. For management purposes, if you need to view content from a few days ago, please go to https://bbs.hcbbs.com/home.php?mod=space&uid=3862647&do=thread&view=me&from=space through the summary post below
①Inadequate system blasting and purging led to a high pressure drop in the system after it was put into operation; this restricted the compressor’s displacement, the hydrogen-to-oil ratio could not meet the required levels, and the poor heat exchange efficiency of the heat exchange equipment hindered an increase in the reaction temperature； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst loading density is low; at the same volume space velocity, the mass space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.
①Inadequate system blasting and purging led to a high pressure drop in the system after it was put into operation; this restricted the compressor’s displacement, the hydrogen-to-oil ratio could not meet the required levels, and the poor heat exchange efficiency of the heat exchange equipment hindered an increase in the reaction temperature； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst loading density is low; at the same volume space velocity, the mass space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.
The commissioning of a hydrogenation unit generally involves several stages: system purging and blasting, catalyst loading, airtightness testing, drying, sulfiding and initial operation stabilization, and switching to the feed oil. The factors affecting the degree of hydrogenation at various stages include: ① Inadequate purging of the system, which results in a high pressure drop after startup; this limits the compressor’s displacement, prevents the hydrogen-to-oil ratio from meeting the required levels, and reduces the heat exchange efficiency of the heat exchange equipment, thereby hindering an increase in reaction temperature ； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst has a low packing density; at the same volume space velocity, the weight space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.
I. Hydrogen partial pressure II. Reaction temperature III. Space velocity IV. Hydrogen-to-oil ratio
①Inadequate system blasting and purging led to a high pressure drop in the system after it was put into operation; this restricted the compressor’s displacement, the hydrogen-to-oil ratio could not meet the required levels, and the poor heat exchange efficiency of the heat exchange equipment hindered an increase in the reaction temperature； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst has a low packing density; at the same volume space velocity, the weight space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.
The commissioning of a hydrogenation unit generally involves several stages: system purging and blasting, catalyst loading, airtightness testing, drying, sulfiding and initial operation stabilization, and switching to the feed oil. The factors affecting the degree of hydrogenation at various stages include: ① Inadequate purging of the system, which results in a high pressure drop after startup; this limits the compressor’s displacement, prevents the hydrogen-to-oil ratio from meeting the required levels, and reduces the heat exchange efficiency of the heat exchange equipment, thereby hindering an increase in reaction temperature ； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst has a low packing density; at the same volume space velocity, the weight space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.
The commissioning of a hydrogenation unit generally involves several stages: system purging and blasting, catalyst loading, airtightness testing, drying, sulfiding and initial operation stabilization, and switching to the feed oil. The factors affecting the degree of hydrogenation at various stages include: ① Inadequate purging of the system, which results in a high pressure drop after startup; this limits the compressor’s displacement, prevents the hydrogen-to-oil ratio from meeting the required levels, and reduces the heat exchange efficiency of the heat exchange equipment, thereby hindering an increase in reaction temperature ； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst has a low packing density; at the same volume space velocity, the weight space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.
Feed temperature, properties of the crude oil, catalyst activity, amount of recycled hydrogen, amount of fresh hydrogen, amount of recycled oil, reaction pressure, etc.
①Inadequate system blasting and purging led to a high pressure drop in the system after it was put into operation; this restricted the compressor’s displacement, the hydrogen-to-oil ratio could not meet the required levels, and the poor heat exchange efficiency of the heat exchange equipment hindered an increase in the reaction temperature； ②The catalyst is not evenly loaded, resulting in channeling and flow deviation ； The internal components of the reactor were not installed properly, resulting in uneven gas-liquid distribution and flow bias ； The catalyst is not properly graded and filled, resulting in a rapid increase in pressure drop, which affects the compressor’s displacement and the improvement of the hydrogen-to-oil ratio ； The catalyst has a low packing density; at the same volume space velocity, the weight space velocity is low, resulting in limited effective activity of the catalyst ； ③Too rapid heating during catalyst drying causes the catalyst to break apart; excessive operating pressure and insufficient holding time result in incomplete dehydration. The drying medium carries hydrocarbons, leading to premature coking of the catalyst ； ④Improper control of vulcanization temperature and holding time leads to incomplete vulcanization and reduction of the catalyst ； Improper selection of sulfurized oil, too fast sulfur injection rate, excessive temperature rise, and premature coking of the catalyst ； ⑤Without preliminary activation and stabilization, the catalyst cokes rapidly ； ⑥During the startup phase, the medium flowing through the furnace tubes was interrupted; dry burning occurred, which led to coking of the furnace tubes. This resulted in high pressure differences across the furnace tubes and excessive surface temperatures, thereby limiting the increase in reaction temperature.