Columnar activated carbon purchase With the deepening of research, zeolite molecular sieves have gradually moved from laboratory to industrial application. Due to its powerful performance, it can be integrated with the reactor. In membrane catalytic reaction, reaction and separation are coupled. At present, the application fields of zeolite membrane are pervaporation, gas separation and membrane reactor. It is the needs of human practical activities and the development of application fields that constantly promote the development of zeolite molecular sieves. From natural zeolite to synthetic zeolite, from low silica zeolite to high silica zeolite; From silicoaluminium molecular sieve to aluminophosphate molecular sieve; From super micropore to mesoporous material; From inorganic porous frameworks to MOFs, and recently emerging macroporous materials, the yield has been effectively improved, and the synthesis cost and environmental pollution have been reduced

Molecular sieve is a crystalline silicate or aluminosilicate, which is a pore and cavity system with molecular size (usually 0.3nm to 2.0nm) formed by connecting silicon oxygen tetrahedron or aluminum oxide tetrahedron through oxygen bridge bond, Columnar activated carbon Hebei Therefore, it has the characteristics of screening molecules. However, with the deepening of molecular sieve synthesis and application research, researchers have found phosphoaluminate molecular sieves, and the skeleton elements (silicon or aluminum or phosphorus) of molecular sieves can also be replaced by B, Ga, Fe, Cr, Ge, Ti, V, Mn, Co, Zn, Be and Cu, and the size of its pores and cavities can also reach more than 2 nm, Columnar activated carbon purchase Therefore, molecular sieves can be divided into silicon aluminum molecular sieves, phosphorus aluminum molecular sieves and skeleton heteroatom molecular sieves according to the composition of skeleton elements;

Columnar activated carbon purchase Rely on its own unique void structure. The pore size of zeolite is uniform, the internal void structure is developed, the specific surface area is large, the adsorption capacity is strong, and contains a large number of invisible pore sizes. The pore size in 1g zeolite material can be expanded to the specific surface area of 500-1000m2, which is higher for special purposes. The mutual adsorption between molecules is also called "van der Waals gravity". Although molecular motion speed is affected by temperature, material and other factors, Columnar activated carbon manufactor But 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.

Columnar activated carbon purchase 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. Columnar activated carbon manufactor 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.

Because there are uniform small internal pores in the molecular sieve structure, Columnar activated carbon Hebei When the molecular linear degree of reactants and products is close to the pore size of the crystal, the selectivity of catalytic reaction often depends on the corresponding size of the molecule and pore size. 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. 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. The OH based acid sensitive site center on the molecular sieve HY obtained by ion exchange, and the aluminum ion outside the framework will strengthen the acid site, forming 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. Columnar activated carbon purchase This method often leads to dealumination of molecular sieve framework. So NaY will become NH4Y and then HY.

Columnar activated carbon manufactor Microporous molecular sieves with molecular pore size below 2 nm and mesoporous molecular sieves with molecular pore size between 2-50 nm (50 nm The above are macroporous molecular sieves), mesoporous molecular sieves have high specific surface area, regular and orderly pore structure, narrow pore size distribution, continuous and adjustable pore size and other characteristics, which make it play an important role in the adsorption, separation and catalytic reaction of macromolecules that are difficult for many microporous molecular sieves to complete. Therefore, molecular sieve materials with different properties and pore sizes shall be configured according to the different components of organic waste gas during selection, so as to achieve targeted organic waste gas treatment, meet the design requirements and emission standards. 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, Columnar activated carbon purchase It is more suitable for the treatment of organic waste gas with large air volume and low concentration.