We often use desiccant in life, commonly used desiccant activated carbon, activated alumina, molecular sieve, silica gel. Different occasions need to use the desiccant is not the same, molecular sieve is mainly used for the depth of the gas drying, drying effect is good, can be recycled, different types of gases can be used in different types of molecular sieve adsorption removal. Today we come to understand the molecular sieve. Molecular sieve is a kind of aluminosilicate, which is mainly composed of silicon aluminum through oxygen bridge to form an open framework structure. In this structure, there are many well-aligned pores of uniform pore size, which have a large internal surface area. In addition, it also contains metal ions with low electricity price and large ionic radius and bound water. Due to the continuous loss of water molecules after heating, but the crystal skeleton structure remains unchanged, forming many cavities of the same size. The cavities are connected by multiple micropores of the same diameter, and the molecules of the material have the same diameter. A pore having a smaller diameter than the pore is adsorbed in the cavity. Molecules larger than the pores are repelled, so molecules of different sizes are separated until the action of the screening molecule is called a molecular sieve. It is mainly used for the deep drying of various gases and liquids, the separation and purification of gases, liquids, catalyst carriers, etc., so it is widely used in oil refining, petrochemical, chemical, metallurgy, electronics, national defense and other industries, and more and more widely used in medical treatment, Optics, agriculture, environmental protection and many other aspects.
3A molecular sieve: mainly used for petroleum cracking gas, olefins, refineries, oil fields, chemical, pharmaceutical, industrial desiccant, insulating glass and other drying. Chemical formula: 2/3k2o · 1/3Na2O · Al2O3 · 2SiO29/2H2O Main uses: 1. Dry liquid, such as ethanol 2. Air drying of hollow glass 3. Dry nitrogen-hydrogen mixed gas 4. Refrigerant drying
4A molecular sieve: mainly used for the drying of natural gas and various chemical gases and liquids, refrigerants, medicines, electronic materials and volatile substances, the purification of argon, and the separation of methane, ethane and propane. Chemical formula: Na2O · Al2O3 · 2SiO2 · 9/2H2O Main uses: 1. Air, natural gas, hydrocarbon well completion, deep dry gas and liquid, refrigerant, etc.; 2. Preparation and purification of argon; 3. Electrostatic drying of electronic components and humidity sensitive substances; Dehydrating agent in paint, polyester fiber, dye and paint.
5A molecular sieve chemical formula: 3/4cao · 1/4na2o · Al2O3 · 2SiO2 · 9/2H2O main purpose: 1. Natural gas drying, desulfurization and decarbonization; 2, nitrogen and oxygen separation, nitrogen and hydrogen separation, oxygen, nitrogen and hydrogen; petroleum dewaxing, separation of normal hydrocarbons and cyclic hydrocarbons from branched hydrocarbons. (Renewable) 4A molecular sieve 13X molecular sieve is mainly used for raw gas purification of large and medium-sized air separation units. Hollow glass special molecular sieve series can absorb the moisture and residual organic matter in the hollow glass at the same time, so that the hollow glass can remain smooth and transparent even at very low temperatures, and fully reduce the internal and external pressure difference. Hollow glass due to seasonal and day-night temperature difference. Thoroughly solve the problem of deformation and damage caused by the expansion or contraction of ordinary insulating glass caused by ordinary insulating glass desiccant, and fully extend the service life of insulating glass.
The 13X molecular sieve active powder series are molecular sieves obtained by dehydrating the original portion of the molecular sieve. It has a certain dispersion and faster adsorption rate. It is mainly used as an additive for paints, coatings, resins and related adhesives. Molecular sieve regeneration In order to obtain good performance and long service life, the molecular sieve must be regenerated after a period of time. Correctly regenerated molecular sieves are as low as fresh molecular sieves, and their adsorption and mechanical properties will decay over time. There are two basic methods for molecular sieve regeneration: 1. Changing the temperature, that is, "temperature change". It removes the adsorbed species by heating the molecular sieve. In industry, it is usually heated by preheated regeneration gas to purge the molecular sieve to about 200°C and remove the desorbed adsorbate. 2, change the relative pressure, that is, "variable pressure". It is commonly used in gas phase adsorption processes. The basic method is to keep the adsorbent temperature constant and remove the adsorbent by reducing the inert gas pressure and backflushing. Regeneration is usually the opposite of adsorption, so most of the adsorbent contained in the adsorbent bed inlet does not have to pass through the entire adsorbent bed, and some molecular sieves may not contact the adsorbent bed. hot wet gas, thereby increasing the life of the molecular sieve. The regeneration gas should be as dry as possible, otherwise it will affect the adsorption efficiency.