the Performance of zeolite 3a molecular sieve

Yu and zeolite 3a molecular sieve  metallic luster, hardness of 3~5, relative density is 2~2.8, colored with natural zeolite, synthetic zeolite is white, insoluble in water, thermal stability and resistance to acid increasing with the improved SiO2/Al2O3 ratio.mole sieve dehydration have very large surface areas, 300~1000m2/g, Crystal surface in highly polarized, is a kind of high efficiency adsorbent, also a solid, the surface has a high acid concentration and intensity, can cause the carbenium ion-catalyzed reactions.When the composition of the metal ion exchange with other ions in solution, you can adjust the aperture, change its adsorption and catalytic properties, which produce different molecular sieve catalysts.

the Type of Synthesis of zeolite and natural zeolite molecular sieve

Synthesis of zeolite and molecular sieve zeolite in two ways.① the most natural zeolite by volcanic Tuff and tuffaceous sedimentary rocks in marine or lacustrine environment reacts to form.Have been found to have more than 1000 kinds of zeolite minerals, more important has 35 species, common clinoptilolite, mordenite zeolite, Mao Feishi and diamond, etc.Mainly in the United States, Japan, France and other countries, China has a number of mordenite and clinoptilolite zeolite deposit, Japan is the biggest national exploitation of natural zeolite.② resource constraints and by natural zeolite, in the 1950 of the 20th century, the extensive use of zeolite synthesis (see table).

Commodities commonly used prefixes digital crystal structure different mole sieve dehydration  re classified, such as 3A, 4 a, 5 a molecular sieves.In table 4 type a is a class aperture 4Å.Recorded as a molecular sieve containing Na+ Na-A if Na+ K+ replacement, Aperture is approximately 3Å, Which is 3 a molecular sieve;1/3 Na+ over Na-A Ca2+ replacement, Aperture is approximately 5Å, Which is 5 a molecular sieves.

the definition of Molecular sieve

Magnitude, it only allows a diameter smaller than the diameter of the molecules into, so molecular sieve zeolite in the mixture can be screened by size.It is called molecular sieve.Back more than 200 years ago, b.Kelongshitaite first named aluminosilicate zeolites, chemistry formula for m and n are metal ions and Valence;Number of molecule x is silicon dioxide;Y is the number of water molecules;P is the atomic number of aluminum;Q is the number of silicon atoms.molecular sieve dehydration process in the chemical industry as a solid adsorbent material desorption of adsorbed by the molecular sieve can be recycled after use.Also used for gas and liquid drying, purification, separation and recycling.Starting in the 1960 of the 20th century, used as a catalyst in the petroleum refining industry, has now developed a variety suitable for different molecular sieve catalysts for catalytic processes.

Generation of molecular sieve crystals

zeolite 3a molecular sieve for ethanol drying is a very complex process, and know it has not very clear conclusion. However, whether liquid or solid phase change mechanism, the entire crystallization process generally includes the following four steps: 1. aging, multi-silicate and aluminate and then polymerized, or re-polymeric phosphate and aluminate, i.e., the initial formation of a gel; 2. nucleation, molecular structure directing agent in the core or a certain organization TO4 tetrahedral basic structural unit, around which is formed during the formation of nuclei; 3 nuclei growth; 4. crystal growth and cause secondary nucleation. Therefore, the zeolite synthesis process control is mainly reflected in the choice of the regulation of the initial gel formulation and crystallization conditions on. Aging conducive to the formation of nuclei. Higher initial supersaturation favor crystal nucleation and growth, and a single crystal is prepared zeolite synthesis system requires good control over saturation. Increasing the reaction temperature, and promote the transformation of thermodynamics, but also by changing the concentration of the reactants and over-saturation affect the crystallization kinetics.

Structure consisting of ZSM-5 zeolite

ZSM-5 zeolite is a high silica pentasil zeolite, its basic structural unit of the eight five-membered ring composed, called cells, these cells formed by edges parallel to the C axis shared five silicon chain, this basic structural unit by edge-linked into a chain structure, then surrounded the zeolite framework. ZSM-5 zeolite crystal structure of the layer in the C-axis projection. sieve molecular zeolite crystal is composed of many such stacked up. ZSM-5 zeolite supplier main channel window ten-membered ring, a pore size of 0.54nm * 0.56nm.

Zeolite structure unit

There is a three-dimensional molecular sieve between four TO4 tetrahedra sharing vertices formed by connecting the skeleton. T backbone atoms generally refers to Si, Al or P atom, in a few cases refer to other atoms, such as B, Ga, etc. These [SiO4], [AlO4] or [PO4] tetrahedral, etc. constitute the basic skeleton of the molecular sieve adsorber unit, i.e. the primary structural unit. In the 3a zeolite molecular sieve, each T atom is coordinated with four oxygen atoms, each oxygen atom bridging two T atoms, and therefore, the [SiO4] and [AlO4] tetrahedral aluminosilicate molecular sieve xh-5 has formed anion skeleton structure, framework negative charge by the additional cation balance. Aluminosilicate zeolite chemical formula: Ax / n (SiO2) (AlO2) xmH2O (A is a cation of valence n), and adsorbed water located in the pores of the cation.

Carbon molecular sieve works

Carbon molecular sieve nitrogen equipment works: carbon molecular sieve nitrogen equipment (CMS-PSA) is a carbon molecular sieve (Carbon Molecular Sieving, abbreviated CMS) as adsorbent and air as raw material, the use of pressure swing adsorption principle of the separation of oxygen and nitrogen production of high pure nitrogen gas separation apparatus.
zeolite 3a molecular sieve for ethanol drying is based on coal as the main raw material selection, grinding, shaping, drying and activation, heat treatment and other processes from the surface is full and efficient non-polar microporous adsorbent. His ability to adsorb gas molecules of different molecular weights are different, and different kinetic diameter of the gas molecules are adsorbed in the hollow glass desiccant molecular sieve pore diffusion at different speeds.
Carbon molecular sieve oxygen and nitrogen co-adsorption exists, at the same adsorption pressure, oxygen, nitrogen adsorption equilibrium was no significant difference (Figure 3) Therefore, the mere change in pressure is difficult to achieve effective separation of oxygen and nitrogen.
The general nature of oxygen and nitrogen, although the difference is small, but its dynamics are different diameters: 3.5 angstroms oxygen, nitrogen is 3.7 angstroms. Although both small pore size than the carbon molecular sieve, but the rate of diffusion of oxygen molecules hundreds of times faster than nitrogen molecules. This is because the smaller the molecule, the faster its diffusion. 4, in a short time, because the rate of diffusion of oxygen molecules than nitrogen molecules, so the oxygen molecules preferentially occupy the center is a large number of molecular sieve dehydration, adsorption capacity after a few minutes to more than 90%, almost close to balance at a time when the amount of nitrogen adsorption of only about 5%. The use of oxygen, nitrogen adsorption difference within a short time of great features, the program controller at a specific time program between two identical adsorption tower fast switching, combined with pressurized oxygen adsorption and desorption of oxygen pressure swing The adsorption process separating oxygen from air. Oxygen-containing gas is discharged from the bottom of the column, nitrogen adsorption due to little or no adsorption in the gas phase and the product gas is enriched in the form of continuous output.

Why molecular sieve at room temperature does not produce water desorption

ethanol dehydration molecular sieve adsorption of water is adsorbed by the van der Waals force, from the microscopic point of view internal pore molecular sieve to reach static equilibrium, the water molecules are polar molecules break down into hydrogen ions and hydroxide ions. In the adsorption process of water molecules in the double glazing molecular sieve with water decomposition of hydrogen ions and hydroxide ions again to reach static equilibrium, pull off the oxygen-hydrogen releases energy (temperature rise phenomenon). The whole process is the physical reaction. Thus Adsorbent Molecular Sieve Kdhf-03 at room temperature does not produce water desorption.

What is the molecular sieve for insulating glass:

Molecular sieve insulating glass all comply with performance indicators and do not have any impact on their physical and chemical properties, only qualified called double glass desiccant molecular sieve for insulating glass. Meet this requirement only Automobile Desiccation Molecular Sieve.

Features of Molecular sieve absorption

activating molecular sieves capacity is very strong (and therefore is widely used as a desiccant), for gas purification, save should avoid direct exposure to the air.Stored for a long time and have moisture absorption regeneration of zeolite molecular sieves should be carried out before use.Molecular sieve avoiding oil and liquid water.Should be used as far as possible avoid contact with oils and liquid water.Drying in production of industrial gases, air, hydrogen, oxygen, nitrogen, argon and so on.Adsorption dryer with two parallel, a job, while the other can be regenerated.Alternating work and regeneration, to ensure a continuous operation.Dryers at 8-12 work under impact regeneration in a heated to 350 degrees.molecular sieve manufacturers regeneration temperature is slightly different in different specifications.Certain organic molecular sieves for gas-phase has a good catalyst.Also known as zeolites and zeolite, is a crystalline aluminosilicate, structured and uniform pores in its crystal structure, molecular size of aperture for

Molecular sieve

Due to contains electric price lower and ion RADIUS larger of metal ion and combined state of water, water molecular in heating Hou continuous to lost, but Crystal skeleton structure not variable, formed has many size same of empty cavity, double glazing molecular sieve empty cavity and has many diameter same of micro-hole connected, these tiny of cavities diameter size uniform, can put than channel diameter small of molecular adsorption to cavities of internal in the to, and put than channel big of molecular exclusion out, thus can put shape diameter size different of molecular, polar degree different of molecular, boiling point different of molecular, Saturation level separating different zeolite 3a molecular sieve  that is, with "screening" molecular function, it is called molecular sieve.Current molecular sieves in the metallurgical, chemical, electronics, petrochemicals, natural gas is widely used in the industry.