What is 13X molecular sieve?

13X molecular sieve is a kind of aluminosilicate adsorbent with a specific crystal structure and properties. Here is a detailed introduction:

13X molecular sieve belongs to the family of zeolite molecular sieves. Its chemical composition can generally be expressed as . It features a uniform microporous structure, where these micropores are formed by connecting silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra through oxygen bridges, creating a three-dimensional network crystal structure. The average pore size is about 10 Å (1 nanometer = 10 Å), allowing molecules with a diameter smaller than 10 Å to enter the pore channels.

Adsorption Performance: It possesses extremely strong adsorption capabilities and can adsorb a wide variety of molecules. It has a good adsorption effect on polar molecules such as water, carbon dioxide, hydrogen sulfide, sulfur dioxide, as well as organic molecules like aromatics and naphthenes. This is because there are a large number of silico-aluminate groups and cations inside its pores and on its surface, and these groups and ions can interact with the adsorbed molecules, thus adsorbing the molecules inside the pores.
Screening Performance: Based on its uniform pore size, 13X molecular sieve can screen molecules according to their size and shape. Only those molecules with a diameter smaller than its pore size can enter the pores and be adsorbed, while those larger than the pore size are blocked outside, thereby realizing the separation and screening of molecules of different sizes.
Ion Exchange Performance: The sodium ions in 13X molecular sieve can be exchanged with other cations. Through ion exchange, the properties and applications of the molecular sieve can be changed. For example, after replacing the sodium ions with other metal ions, the adsorption selectivity and catalytic properties of the molecular sieve may change, thus meeting different application requirements.

Hydrothermal Synthesis Method: This is the most commonly used method for preparing 13X molecular sieve. Usually, with silicon sources (such as sodium silicate), aluminum sources (such as sodium metaaluminate), alkalis (such as sodium hydroxide), and water as raw materials, under certain temperature and pressure, the silico-aluminate species polymerize and crystallize through hydrothermal reaction to form 13X molecular sieve crystals. During the reaction, factors such as the ratio of raw materials, reaction temperature, reaction time, and stirring speed will affect the crystal structure, particle size, and properties of the molecular sieve.
Ion Exchange Method: On the basis of preparing the sodium-type 13X molecular sieve, through the ion exchange process, part or all of the sodium ions can be replaced by other cations, such as calcium ions, magnesium ions, lithium ions, etc., so as to obtain different ion forms of 13X molecular sieve to meet specific application requirements.

Gas Separation and Purification: In air separation devices, it is used to remove impurities such as water and carbon dioxide from the air, ensuring the high efficiency and stability of the air separation process. In the field of natural gas purification, it can remove hydrogen sulfide, carbon dioxide, and water, improving the quality of natural gas.
Petrochemical Industry: In the drying and purification of petroleum cracking gas, it can effectively remove water and impurities, protecting subsequent processing equipment and catalysts. In the desulfurization and denitrification of oil products, its adsorption performance is utilized to remove sulfur- and nitrogen-containing compounds from the oil products, reducing the sulfur and nitrogen content of the oil products and minimizing environmental pollution.
Environmental Protection: It can be used to treat pollutants such as sulfur dioxide and nitrogen oxides in industrial waste gas. Through adsorption, these harmful gases are removed from the waste gas to achieve the purpose of purifying the air. In wastewater treatment, it has a certain adsorption and removal effect on heavy metal ions and organic substances in water, helping to improve water quality.