What is antimony related to in catalytic cracking catalysts?
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What is the relationship between antimony on catalytic cracking catalysts and other factors? What does the amount of antimony indicate? Currently, the antimony content in catalysts varies significantly; what causes this? Is it the catalyst itself that has an impact, or are metal deactivators the cause?
I guess you used too much metal passivator?
The large variation in antimony content is likely due to fluctuations in the amount of metal passivator added
Control the amount of passivator added~~
What I want to ask is whether this is related to the catalyst. I have two sets of catalysts here, and they use different types of catalysts. In one set, the amount of passivator added is low, but the rate of antimony deposition on the catalyst is high; in the other set, more passivator is used, yet the rate of antimony deposition on the catalyst is low
Is it harmful to use too much passivator? Apart from being a waste?
An excess of antimony can also affect the crystal structure of the catalyst. When the antimony-nickel ratio in the balancing agent exceeds around 0.4, caution is needed! (Our actual refueling experience combined with the official guidance from the China Institute of Rock and Mineral Sciences!) ）
The amount of passivator to be added is generally considered to be such that the antimony/nickel ratio on the catalyst lies between 0.3 and 1.0. The antimony content in catalytic cracking catalysts is related both to the amount of catalyst added and to the catalyst loss; therefore, the amount of passivator should be adjusted based on the desired antimony/nickel ratio.
The function of a passivator is to reduce heavy metal pollution, minimize catalyst poisoning, control product quality, and decrease side reactions. The level of antimony content in the catalyst is determined by the amount of passivator added; a high antimony content indicates that too much passivator has been used. At the same time, it is necessary to pay attention to the changes in the ratio of methane to hydrogen in the dry gas sample. If the variation in hydrogen content remains within normal limits, it suggests that the appropriate amount of passivator has been used. Alternatively, the ratio of antimony to nickel content in the catalyst can be used to make such a determination. There are many reasons for the significant variations in the antimony content of catalysts as determined by analytical tests. Firstly, the opening degree of the valve at the outlet of the passivation agent pump plays a role; the concentration of the passivation agent itself is also important. An excessively high preheating temperature of the feed materials can cause the passivation agent to decompose due to heat. Poor electrodesalination of the feed materials, as well as changes in the properties of the crude oil leading to higher levels of heavy metals, can all have an impact. Additionally, the operating conditions of the reaction process also matter.