Because there are uniform small internal pores in the molecular sieve structure, Sponge activated carbon Yichun 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. Sponge activated carbon major This method often leads to dealumination of molecular sieve framework. So NaY will become NH4Y and then HY.

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, Sponge activated carbon Yichun 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. Sponge 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.

Sponge activated carbon major 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, Sponge 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.

With the continuous deepening of research, honeycomb zeolite molecular sieve has gradually moved from laboratory to industrial practical application. Due to its powerful performance, it can be integrated with the reactor, Yichun Sponge activated carbon In membrane catalytic reaction, the reaction is coupled with separation. 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; Sponge activated carbon major The development from inorganic porous frameworks to MOFs, as well as the recent emergence of macroporous materials, has effectively improved the yield, reduced the synthesis cost and environmental pollution.

Sponge activated carbon major 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

Sponge activated carbon major Since UCC scientists invented synthetic molecular sieves in the late 1940s, UOP's molecular sieve technology has changed with each passing day. Today, UOP molecular sieve is famous for its high efficiency, low consumption and reliability. With the high adsorption capacity of UOP molecular sieve, users may reduce the loading capacity of molecular sieve and extend the adsorption cycle. More importantly, with this advantage, users can significantly reduce their investment and operating costs and reduce energy consumption. This is particularly noticeable in today's increasingly tense energy. The adsorption or repulsion function of molecular sieves is affected by the molecular electricity. Synthetic zeolite has the special function of selective adsorption according to the size and polarity of molecules, so it can dry or purify gas or liquid, Sponge activated carbon Yichun This is also the basis for molecular sieve separation. Synthetic zeolite can meet the extensive demand of industry for adsorption and selective products, and is also widely used in industrial separation to synthesize zeolite molecular sieves. Advantages of UOP molecular sieve