[Q&A Question 221] 11.27.2016
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【Q&A Question 221】November 27, 2016: What are the factors affecting the activity of hydrogenation catalysts? A reference ** will be shown after responding; scoring is achieved by answering the key points. 1. Impurities in the reaction raw materials can cause the catalyst to become poisoned and lose its activity. 2. During use, coking on the catalyst surface and carbon deposition reduce the available surface area of the catalyst, leading to a decrease in its activity. 3. Prolonged use of the catalyst at high temperatures causes the crystal grains of its active components to grow, reducing its specific surface area and leading to a decline in its activity. 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 Chemicals Forum)
1. Properties of the raw materials, metal content, resinous asphaltenes, etc. 2. Hydrogen-to-oil ratio, hydrogen purity, hydrogen partial pressure, etc. 3. Space velocity 4. Reaction temperature,
The properties of the feedstock, space velocity, hydrogen-to-oil ratio, purity of recycled hydrogen, hydrogen partial pressure, and the degree of catalyst coking
The quality of pre-vulcanization, the quality of catalyst loading, hydrogen-to-oil ratio control, reaction pressure control, and temperature control!
Operating time, coking condition, and what else?
(1) A framework with certain structural components is required. When solid catalysts are used, their particle size and good mechanical strength ensure that their hydrodynamic properties meet the requirements of the catalytic process. (2) Improve the utilization rate of the active group that can be approached. It provides the active component with a large surface area, which facilitates the diffusion and adsorption of reactant molecules, as well as surface reactions, as well as the desorption and diffusion of product molecules in multiphase catalytic reactions. (3) Improve the thermal stability of the catalyst. The active components existing alone are subject to the thermodynamic tendency to reduce surface free energy, resulting in a strong tendency to aggregate. The carrier possesses good thermal stability, and it acts as a barrier to the movement and approach of highly dispersed active component particles, thereby raising the temperature at which sintering of the active components occurs. Research Progress on Factors Affecting the Activity of Hydrodesulfurization Catalysts _ Document Download http://www.wenku*azai.com/doc/47547e166c175f0e7cd137e4.html
1. Temperature has a significant impact on the activity of catalysts. When the temperature is too low, the catalyst’s activity is very low and the reaction rate is slow. As the temperature increases, the reaction rate gradually rises, but after reaching its maximum value, it starts to decrease again. The vast majority of catalysts have a specific range of active temperatures; if the temperature is too high, it can cause the catalyst to sinter, thereby destroying its activity. 2. Catalyst coking reduces its activity; as the reaction time increases, carbon deposition on the catalyst increases, further decreasing its activity. 3. An increase in side reactions also reduces the catalyst’s activity.
Catalyst poisoning, high-temperature thermal deactivation, carbon deposition.
1. Properties of raw materials； 2. Properties of catalyst particles ； 3. Active metal content and distribution ； 4. Reaction temperature ； 5. Reaction pressure ； 6. Air velocity ； 7. Specific surface area ； 8. Loading effect.
Temperature, oil properties, purity of recycled hydrogen
1. Reaction temperature 2. Space velocity 3. Hydrogen-to-oil ratio 4. Hydrogen partial pressure