Honeycomb activated carbon major Because the silicon (aluminum) oxygen tetrahedron of natural zeolite crystal has many holes and channels, which occupy cations and water molecules. When some other goods are completely dehydrated after baking, the crystal skeleton is not damaged, but forms large holes on the inner surface, which can absorb and store a large number of molecules, so it has the characteristics of large adsorption capacity and high selectivity. There are cavities and channels in the crystal structure of zeolite with large adsorption capacity, whose volume accounts for more than 50% of the total volume of zeolite crystals. Moreover, the micropores of zeolite are evenly distributed, and the pore size is small, which is equivalent to the molecular size of general substances. The internal surface area of zeolite crystals can reach more than 1000 square meters. Therefore, the adsorption capacity of zeolite is particularly large. Honeycomb activated carbon Direct selling In different zeolite minerals, the proportion of silicon and aluminum is different, and the different proportion will cause some characteristics of zeolite changes, such as ion exchange and acid resistance.

Molecular sieve has clear pore cavity distribution, extremely high internal surface area (600m2/s), good thermal stability (1000 ℃), and adjustable acid site center. The acidity of molecular sieve mainly comes from three coordinated aluminum atoms and aluminum ions (AlO)+on the framework and in the pores. OH based acid sensitive site center on molecular sieve HY obtained by ion exchange, Honeycomb activated carbon Jiujiang The aluminum ions outside the framework will strengthen the acid site and form the L acid site center. Polyvalent cations such as Ca2+, Mg2+and La3+can show the acid site center after exchange. The reduction of transition metal ions such as Cu2+and Ag+can also form acid site centers. In general, the higher the Al/Si ratio, the higher the specific activity of OH group. The modification of zeolite acidity can introduce protons through direct exchange of dilute hydrochloric acid. This method often leads to dealumination of molecular sieve framework. So NaY will become NH4Y and then HY. Because there are uniform small internal pores in the structure of molecular sieves, when the molecular linearity of reactants and products is close to the pore size in the crystal, the selectivity of catalytic reaction often depends on the corresponding size of molecules and pore size. Honeycomb activated carbon major This selectivity is called shape selective catalysis. There are two mechanisms leading to shape selectivity. One is caused by the difference of diffusion coefficient of molecules participating in the reaction in the pore cavity, which is called mass transfer selectivity; The other is caused by the space limitation of the transition state of the catalytic reaction, which is called transition state selectivity.

Jiujiang Honeycomb activated carbon Zeolite is a porous aluminosilicate crystal (a1uminsi1ict) with a water bearing frame structure, which exists naturally in nature and is also artificially synthesized. The ideal chemical formula of zeolite can be expressed as Mx/yA1XSiyO2 (x y) P? H2O, In the formula, M refers to alkali metals (such as Na, K, Li) and alkaline earth metals (such as Ca, Mg, Ba, Sr). The chemical composition of zeolite is generally considered to be composed of A12O3, SiO2, H2O and metal cations, of which A12O3 and SiO2 account for about 80% of the total amount of zeolite minerals. In different zeolite minerals, the proportion of silicon and aluminum is different, Honeycomb activated carbon Direct selling And the different proportion of zeolite will cause some changes in zeolite characteristics, such as ion exchange and acid resistance. Because the silicon (aluminum) oxygen tetrahedron of natural zeolite crystal has many holes and channels, which occupy cations and water molecules. When some other goods are completely dehydrated after baking, the crystal skeleton is not damaged, but forms large holes on the inner surface, which can absorb and store a large number of molecules, so it has the characteristics of large adsorption capacity and high selectivity.

High silica zeolite type molecular sieves, this kind of zeolite has a series, and ZSM-5 is widely used, with ZSM-8 and ZSM-11 having the same structure; The other group is ZSM-21, ZSM-35 and ZSM-38. ZSM-5 is often called high silica zeolite, with the Si/Al ratio up to 50 and ZSM-8 up to 100. This group of molecular sieves also shows hydrophobic characteristics. Honeycomb activated carbon Direct selling Their structural units are similar to those of mordenite, consisting of pairs of five membered rings, with no cage like cavities and only channels. ZSM-5 has two sets of cross channels, one is straight through, the other is zigzag perpendicular to each other, both formed by ten yuan rings. The channel is oval and its window diameter is (0.55-0.60) nm. Honeycomb activated carbon major Zeolites belonging to the high silicon group also have silicalite-1 of all silicon type, which has the same structure as ZSM-5, and silicalite-2 is the same as ZSM-11.

Honeycomb activated carbon major The mutual adsorption between molecules is also called "van der Waals gravity". Although molecular motion speed is affected by temperature, material and other reasons, it always keeps moving in the micro environment. Due to the mutual attraction force between molecules, when a molecule is trapped in the inner pore volume of zeolite, it will lead to more molecules being absorbed until the adsorption of zeolite is saturated. Physical adsorption mainly occurs in the process of removing impurities from the liquid and gas phases of zeolite. The porous structure of zeolite provides a large amount of specific surface area, which makes it very easy to absorb and collect impurities. Due to the interaction of molecules, a large number of molecules on the pore wall of zeolite can generate strong gravity, just like magnetic force, So as to achieve the purpose of attracting impurities in the medium to the aperture. Honeycomb activated carbon Jiujiang Chemical adsorption In addition to physical adsorption, chemical reaction also often occurs on the surface of zeolite, which contains a small amount of chemical combination, oxygen and hydrogen in the form of functional groups. These surfaces contain oxides of earth or complexes that can react with the adsorbed substances, and then combine with the adsorbed substances to gather inside and on the surface of zeolite.