Problems with balance agents in catalytic cracking systems
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What is causing the continuous decrease in the specific surface area of the system balance agent in catalytic cracking units? How should this problem be solved?
Let’s start with the definition: Specific surface area is defined as the total external surface area of all particles per gram of a substance; its unit in the international system is m2/g. As for its influence, specific surface area is an important parameter for evaluating the properties of a substance, and its value is closely related to the particle size, shape, surface defects, and pore structure. In normal production, as the catalyst is used, its structure deteriorates due to factors such as temperature, pressure, and heavy metals. At the same time, the decrease in specific surface area affects the efficiency of the catalyst to a certain extent, which is reflected in the yield of the product!
This post was last edited by longziyun on 2018-9-25 at 22:38. It is normal for the specific surface area of the balance agent to keep decreasing; the only way to maintain or increase the catalyst’s activity is by replacing it with fresh catalyst, there is no other solution.
Specific surface area is an important parameter for measuring the properties of a material, and its value is closely related to the particle size, shape, surface defects, and pore structure.
Catalytic cracking processes heavy oil, which has a high metal content as well as a high carbon residue content. At high temperatures, the heavy metals in the catalytically cracked oil deposit on the catalyst along with carbon deposits. During catalyst regeneration by burning, the metals remain unchanged, while most of the carbon deposits can be burned; this only improves the catalyst’s activity to some extent and results in a decrease in the specific surface area of the catalyst. To slow down this reduction in specific surface area, it is possible to use oil obtained from the hydrogenation of residue oil as raw material, or to add fresh catalysts in a timely manner.
The addition of fresh dose to the device is already relatively high, but it is still not possible to maintain a high specific surface area. Surely, the factor that causes the specific surface area to keep decreasing is the most important one, right?
Don’t your company conduct any other analyses on catalysts? The most important properties of catalysts are things like activity and mechanical strength; why focus on a relatively one-sided parameter such as specific surface area? If there are problems with the catalyst, it is necessary for the catalyst manufacturer, the design team, and the user (themselves) to work together to identify the cause. Factors such as quality issues with the catalyst itself, problems in the operation of the reaction and regeneration system equipment, or the quality of the oil being processed (high levels of heavy metals, sodium, residual carbon, and certain components) can all lead to a decrease in the catalyst’s activity and its specific surface area. Additionally, insufficient use of passivators can also contribute to these issues.