【Q&A Question 214】November 20, 2016
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【Q&A Question 214】November 20, 2016: Why is it necessary to add scale inhibitors in hydroprocessing? A reference ** will be shown after responding; scoring is achieved by answering the key points. The feed to the hydrogenation unit contains a high amount of sulfides and nitrides, as well as small amounts of gums, asphalts, heavy metals, dissolved oxygen, and solid suspended particles such as coke dust, corrosion products, and inorganic salts of metals. Scaling occurs during heat exchange in the feedstock heat exchanger, which reduces its heat transfer efficiency and increases the load on the furnace. Furthermore, as the production cycle lengthens, a type of scale forms on the inner walls of the heat exchanger tubes that handle crude oil and reaction products; this scale is primarily composed of polycyclic aromatic hydrocarbons, and it is insoluble in water, oil, acids, and bases. This situation affects the normal operation of the cycle. A scale inhibitor is injected before the heat exchanger to form a protective layer on the tubes of the equipment. Therefore, scale inhibitors must be added during hydroprocessing. Summary post of Q&A from 2016 (updated as of November~~~~) http://bbs.hcbbs.com/thread-1597792-1-1.html Seeking sponsors for the “2016 Haichuan Top 10 Members Selection Contest” http://bbs.hcbbs.com/thread-1628108-1-1.html (Source: Haichuan Chemical Forum)
A protective film is formed to prevent scaling.
Because the raw materials contain olefins, especially dienes, olefins polymerize at high temperatures
Prevent large-molecule oils from accumulating on the inner walls of heat exchange equipment, which could increase pressure drop and affect the heat exchange efficiency
Prevent large-molecule oils from accumulating on the inner walls of heat exchange equipment, which could increase pressure drop and affect the heat exchange efficiency
We do not use scale inhibitors in either gasoline hydrogenation or diesel hydrogenation here.
The feed to the hydrogenation unit contains a high amount of sulfides and nitrides, as well as small amounts of gums, asphalts, heavy metals, dissolved oxygen, and solid suspended particles such as coke dust, corrosion products, and inorganic salts of metals. Scaling occurs during heat exchange in the feedstock heat exchanger, which reduces its heat transfer efficiency and increases the load on the furnace. Furthermore, as the production cycle lengthens, a type of scale forms on the inner walls of the heat exchanger tubes that handle crude oil and reaction products; this scale is primarily composed of polycyclic aromatic hydrocarbons, and it is insoluble in water, oil, acids, and bases. This situation affects the normal operation of the cycle. A scale inhibitor is injected before the heat exchanger to form a protective layer on the tubes of the equipment. Therefore, scale inhibitors must be added during hydroprocessing.
Prevent scaling in heat exchangers and reduce heat transfer efficiency
Prevents scaling in heat exchangers and pipelines by forming a protective layer on their inner walls