catalyst

What catalyst are you talking about?

Reply 2# 276957697 FDFCC-3 is a balancing agent used for catalytic cracking catalytic start-up!

Similar to fresh agent, activity, specific surface area, pore volume, stack ratio, unit cell constant, sieving composition, heavy metal content

Reply 5# hhwangsong We just did a burn reduction or something!

Various indicators of the catalyst and their significance 1. Chemical indicators The chemical composition of the catalyst indicates the main components and the content of impurities in the catalyst, usually including: There are five main indicators: Al2O3, Na2O, Fe2O3, ignition loss, and sometimes Re2O3. 1. Al2O3 content: The Al2O3 content in the catalyst represents the total content of Al2O3 in the catalyst, which is the main chemical component of the catalyst. 2. Na2O content: The Na2O content indicates the Na2O impurity content contained in the catalyst. In the catalytic cracking process, especially when blending residual oil with high vanadium content, 3. Fe2O3 content: Fe2O3 content indicates the Fe2O3 impurity content contained in the catalyst. Fe2O3 will decompose and deposit on the catalyst at high temperatures. If accumulated to a certain extent, it will cause catalyst poisoning. The first result is that the catalyst activity will be reduced. 4. SO42-content: The SO42- content represents the SO42- impurity content contained in the catalyst. SO42- can react with metal oxides (such as alumina, etc.) that have vanadium capture capabilities to form stable sulfates, thereby losing their vanadium capture capabilities. Therefore, in the case of blending residual oil, SO42- is more harmful. 5. Burning reduction: Loss on ignition refers to the content of volatile components such as water, ammonium salts and carbon particles contained in the catalyst. During production, the reduction is controlled to ≤13%. 6. Re2O3 content: Re2O3 content is one of the indicators indicating catalyst performance. Rare earths usually come from molecular sieves in catalysts, and rare earth ions are sometimes introduced into the catalyst manufacturing process to improve performance. Generally, the higher the Re2O3 content, the higher the catalyst activity, but the coke yield is also higher. For balanced catalysts, it is sometimes necessary to know the metal content, such as Ni, V, Na, etc., in order to understand the degree of pollution of the catalyst. 2. Physical properties Physical properties represent the shape, structure, density, particle size and other properties of the catalyst. usually include: Five main items are composed of specific surface area, pore volume, apparent bulk density, wear index and screening. They are briefly described below: 1. Specific surface area The specific surface area of ​​the catalyst is the sum of the inner surface area and the outer surface area. The inner surface area refers to the surface area inside the catalyst pores, and the outer surface area refers to the surface area outside the catalyst pores. Generally, the inner surface area is much larger than the outer surface area. The surface area per unit weight of the catalyst is called specific surface area. Specific surface area is an important indicator of catalyst performance. Different products have different carriers and preparation processes, so there is no direct correspondence between specific surface area and activity. The method used to determine the specific surface area is the nitrogen adsorption capacity method. 2. Pore volume Pore volume is a physical quantity that describes the pore structure of a catalyst. The pore structure not only affects the activity and selectivity of the catalyst, but also affects the mechanical strength, life and heat resistance of the catalyst. The pore volume is the total volume of the micropores in the porous catalyst particles, and the unit is ml/g. The size of the pore volume is mainly closely related to the carrier in the catalyst. For the same type of catalyst, the pore volume will decrease and the pore diameter will increase during use. The method used for pore volume measurement is the water drop method. 3. Wear index An excellent catalytic cracking catalyst must not only have the characteristics of high activity and good selectivity, but also must have certain wear-resistant mechanical strength. Catalysts with poor mechanical strength will not only cause high running losses during operation, increase the amount of catalyst, and pollute the environment. In serious cases, they will destroy the reasonable distribution of the catalyst in the dilute and dense phases, and even make the production equipment unable to operate. The wear resistance of the catalyst is determined by the type of binder during the preparation process. Generally, the catalyst with aluminum sol as the binder has the best strength and the smallest wear index. ； The catalyst with fully synthetic silica-alumina sol as the binder has the worst strength and has a high wear index. At present, the "wear index" is used to evaluate the wear resistance strength of microsphere catalysts. The measurement method is: Put a certain amount of catalyst into the wear index measuring device and blow and grind it at a constant gas speed for 5 hours. The amount of catalyst blown out in the first hour