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

Small block activated carbon purchase 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, Small block activated carbon Direct selling Their polarity and molecular size are different, and competition will occur during adsorption.

Small block activated carbon purchase 1. From the composition of both, carbon molecular sieve is an excellent non-polar carbon material, while zeolite molecular sieve is a hydrate of crystalline aluminosilicate metal salt. The two are completely different in the periodic table of chemical elements! 2. With different pore sizes, the pore composition of zeolite molecular sieves is clearly registered, which can be generally divided into macropores, mesopores and micropores, and there are interconnections between the pores, while carbon molecular sieves are generally micropores! 3. The adsorption principle is different. Zeolite molecular sieves absorb molecules of certain size and repel molecules of larger substances. Small block activated carbon Nanchang Carbon molecular sieve contains a large number of micropores, which can effectively separate the components of gas mixture. 4. The uses are also different. Carbon molecular sieves are widely used in coal fields, petroleum, chemicals, metal heat treatment, electronic manufacturing, food preservation and other industries, while zeolite molecular sieves can be used in addition to petroleum, chemicals, natural gas, electronic production, industrial gas separation, pharmaceutical industry, refrigeration industry, and hollow glass manufacturing.

Small block activated carbon Nanchang 】Zeolite adsorbent has outstanding advantages 1. Strong adsorption selectivity. The pore size of molecular sieve is uniform, and it is also an ionic adsorbent. Therefore, it can selectively adsorb according to the size and polarity of molecules. It can effectively remove ethylene, propylene and acetylene from saturated hydrocarbons, which is determined by its strong polarity. 2. Strong adsorption capacity. Even if the composition concentration of the gas is very low, it still has the adsorption capacity of. 3. It is less affected by temperature. At a higher temperature, it still has a greater adsorption capacity, while other adsorbents are greatly affected by temperature, so at the same temperature, the adsorption capacity of zeolite molecular sieve is large. 4. It can be regenerated at high temperature, with high regeneration efficiency and high safety. 5. Strong resistance to poisoning and good thermal stability. Zeolite molecular sieve is an excellent adsorbent, Small block activated carbon purchase It is widely used in the production of basic organic chemical industry and petrochemical industry, as well as in the treatment of harmful gases nox、co、co2，nh3，ccl4、 Purification of water vapor and gaseous hydrocarbon waste gas; As well as air purification and deodorization in biochemical industry, paint industry, underground places, leather factories and animal breeding places; Adsorption of flue gas odor, removal of mercury vapor, etc.

Small block activated carbon Nanchang Because the aluminum oxide tetrahedron of zeolite has a negative charge, and the skeleton hole contains cations, a strong electric field is formed 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 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.