Adsorption Principle and Application of Molecular Sieves
Molecular sieves are aluminosilicate crystals synthesized by artificial hydrothermal method. Different types of molecular sieves are produced with different Si/Al ratios. For example, Type A, Type X, Type Y, etc. After exchanging different metal cations, they become molecular sieves of the same type and different types. Different substance molecules are adsorbed or repelled according to the size of pores in the crystals, and the adsorption order is determined according to the polarity or polarizability of different substance molecules, thus achieving the separation effect. Therefore, molecular sieves are called "molecular sieves" figuratively. The pore size distribution of molecular sieves is very uniform, so molecular sieves have unique advantages over other types of adsorbents:
It has extremely high separation degree of deep drying.
The co-adsorption phenomenon generate during separation can be effectively avoid, and that product yield is improved. ;
Drying and substance purification can be completed simultaneously in the same system;
Under the condition of higher temperature, it also has certain adsorption capacity.
Compared with other drying and separating devices, the molecular sieve system has low equipment investment and low operation cost.
oil refining
TOP provides a series of professional molecular sieve products for the petroleum refining industry.
Drying of alkylation raw materials-molecular sieve helps to reduce acid consumption, reduce the use and erosion of regenerators, and improve the overall level of alkylation quality.
Drying and purification of refinery hydrogen-prevent corrosion of downstream equipment and filter out chlorine regenerated from catalyst.
Drying of refinery gas-used to prevent pipeline freezing during deep cold working of reformed gas.
Drying and Purification of Refinery Products-Used for Drying and Desulfurizing Liquefied Petroleum Gas (LPG) and Drying Naphtha and Kerosene.
Isomerization treatment-used for drying and purifying raw materials and regenerated hydrogen.
AHR Ethanol Dehydration-Molecular Sieves Dehydrate to Gasoline Grade Purity. Compared with azeotropic distillation, it can not only reduce investment and operating costs, but also has greater flexibility in operation, and does not need to treat benzene and cyclohexane.
Pressure swing adsorption (PSA-H2) hydrogen purification process.
Separation of Industrial Gas and Air
There are many production methods for high purity industrial gases such as O2, N2,H2 and CO, and TOP molecular sieve plays a key role in these production processes due to its high adsorption selectivity and high adsorption capacity.
Molecular sieve is an indispensable part in the process of producing high purity H2 and CO by cryogenic method.
In a typical cryogenic process, synthesis gas (mainly composed of H2 and CO) obtained from natural gas reforming firstly passes through an adsorption bed to remove most of CO2. Then, the synthesis gas saturated with water vapor (which still contains ppm CO2) passes through the molecular sieve adsorption bed to remove the water and CO2 content to a level far less than 1ppm. This ensures that the pipeline will not be blocked due to freezing of water and CO2 in the cryogenic separation process of the subsequent process. The use of molecular sieve adsorbents with high adsorption capacity and long service life is also helpful to reduce equipment investment and operating costs.
H2 can also be produced by non-cryogenic means, i.e. molecular sieve adsorption. Highly selective molecular sieve adsorbents can reduce the content of impurities to a relatively low level and ensure the purity of the produced H2 gas to reach more than 99.9%.
Molecular sieves are used in the production of high purity O2 and N2 by cryogenic rectification or adsorption process in air separation.
In the general cryogenic process, the compressed and low-temperature cooled air is adsorbed through a molecular sieve bed, wherein the H2O and CO2 contents can be reduced to below 1ppm, thus effectively preventing freezing and blocking of low-temperature equipment when O2 and N2 are separated.
The 13XAPG molecular sieve specially used for TOP air separation has high adsorption capacity and high selectivity for H2O and CO2, and its product performance and adsorption index reach the industry standard.
When oxygen is produced by molecular sieve adsorption, air under normal pressure enters the molecular sieve adsorption bed, and efficient molecular sieve removes water, CO2 and N2 from the air to obtain 95% oxygen. PSAO2-HP molecular sieve of TOP product also has high adsorption capacity and high selectivity for H2O, CO2 and N2 in pressure swing adsorption process.
freeze drying
TOP provides molecular sieve desiccant for air conditioning and refrigeration systems in automobiles, household appliances and industrial buildings.
The molecular sieve desiccant with high dry capacity produced by TOP is compatible with refrigerant and lubricant, which can effectively prevent equipment failure. XH series molecular sieve desiccant has high mechanical strength and particle integrity, which can prevent drying agent particles from being broken and worn, especially in automotive air conditioning systems with severe vibration. These characteristics ensure TOP molecular sieve desiccant's advantages in economy and operational reliability.
Petrochemical industry
TOP molecular sieve products provide technology and product services for olefin industry.
All ethylene producers in the world are using molecular sieve desiccant. TOP Will Make New Contributions to the Development of Olefin Industry with Innovative Technology
The polymerization unit has very high requirements for raw gas. It must rely on advanced molecular sieve products and corresponding application technologies to protect the polymerization catalyst so as to produce high-quality polymer products. TOP can not only provide high-quality molecular sieves according to customers' requirements, but also provide on-site services according to the design of adsorption systems.
Users can use TOP molecular sieve products to effectively dehydrate ethylene, styrene and other materials. With TOP's special molecular sieve, the monomer products can meet the requirements of polymerization grade. TOP molecular sieve can also help remove trace pollutants in many technological processes, including regenerated molecular sieves used in sulfur, nitrogen mixing, oxidation, mercury treatment processes, solvents, comonomer treatment processes, and non-regenerated molecular sieves used in arsenic-containing and sulfur-containing mixture treatment.
TOP's products have high quality standards and strict requirements to extend their service life.
Transportation/truck transportation
TOP quality molecular sieve can make your pneumatic brake system achieve the most reliable performance.
TOP-AB is an ideal choice for braking systems of heavy trucks and railway locomotives. The product has the following characteristics: large dew point reduction, high dynamic drying capacity, long-lasting performance even if coated with compressor oil, and strength and wear resistance against severe vibration.
Natural gas
TOP provides the widest range of molecular sieve products for natural gas drying, including:
4A-DG1/16 ",1/8" stripes and 1/8 "trilobate series products are used in TOP molecular sieve natural gas dryer.
Using 4A-LNG can remove CO2,H2S and low molecular weight mercaptans from natural gas.
The RK-29 molecular sieve used only in the liquid natural gas treatment plant removes H2S and low molecular weight mercaptans from propane, removes COS from propane with RK-29 molecular sieve, and removes high molecular weight mercaptans from butane with 13X molecular sieve
