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 Zeolite honeycomb molecular sieve
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Guangzhou high-quality honeycomb activated carbon direct sales

2020-06-11
 Guangzhou high-quality honeycomb activated carbon direct sales

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 Guangzhou 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 molecular sieve structure, when the molecular linearity of reactants and products is close to the pore size of the crystal, the selectivity of the catalytic reaction often depends on the corresponding size of the molecule and pore size. Honeycomb activated carbon high quality 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.

 Guangzhou high-quality honeycomb activated carbon direct sales

Honeycomb activated carbon high quality 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 Guangzhou 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.

 Guangzhou high-quality honeycomb activated carbon direct sales

Honeycomb activated carbon high quality 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 or complexes that can react with the adsorbed substances, so that they can combine with the adsorbed substances and aggregate to the interior and surface of zeolite. Honeycomb activated carbon Guangzhou The main material of honeycomb zeolite adsorbent is natural zeolite. The manufacturer of zeolite is composed of silica Inorganic microporous material composed of al_2o_3 and alkaline metal or alkaline earth metal, with inner pore volume accounting for 40-50% of the total volume and specific surface area of 100-500 m2/g, is characterized by high temperature resistance, non flammability, good thermal stability and hydrothermal stability. It is an efficient molecular sieve carrier with good adsorption performance, no secondary pollution, and can be regenerated at high temperature. Compared with honeycomb activated carbon, its performance is about 25% of its efficiency, However, it is widely used in the fields of adsorption, separation, catalysis and environment due to its high temperature resistance and difficult ignition. It is more suitable for the treatment of organic waste gas with large air volume and low concentration.

 Guangzhou high-quality honeycomb activated carbon direct sales

Honeycomb activated carbon high quality The highly effective selective adsorption is due to the fact that the alumina tetrahedron of zeolite has a negative charge, while the skeleton hole contains cations, which forms a strong electric field around the cations. Therefore, the adsorption force of zeolite not only has a strong dispersion force, but also has a large electrostatic force. It is precisely because of this electrostatic relationship that zeolites have preferential selective adsorption on polar, unsaturated and polarizable molecules. It can strongly adsorb molecules containing polar groups such as hydroxyl ion, ammonium ion and other polarizable groups, especially water, which can form hydrogen bonds with aluminum silicon skeleton, so zeolite has strong water absorption. It can still adsorb even under low relative humidity and concentration, and its water absorption is higher than that of silica gel and activated alumina. The adsorption capacity of zeolite for organic pollutants mainly depends on the polar size and molecular diameter of organic molecules. Small molecules are easier to be adsorbed than large molecules, while polar molecules are easier to be adsorbed than non-polar ones. Different substances (such as organic molecules, metal ions and water molecules) exist in water, Honeycomb activated carbon Direct selling Their polarity and molecular size are different, and competition will occur during adsorption.