Properties of Molecular Sieves

Molecular sieves have strong hygroscopicity and should be used for purification of gases. When preserved, direct exposure to air should be avoided. Molecular sieves with long storage time and moisture absorption should be regenerated before use. Molecular sieves avoid oil and liquid water. Avoid contact with oil and liquid water when using. In industrial production, the drying gases are air, hydrogen, oxygen, nitrogen, argon and so on. Two adsorption dryers are connected in parallel, one working, and the other can be regenerated. Alternate work and regeneration to ensure continuous operation of equipment. The dryer works at 8 - 12 C and regenerates by flushing gas at 350 C. The regeneration temperature of different sieves is slightly different. Molecular sieves have good catalytic activity for some organic gas phase reactions.

Type 3A zeolite:

It is mainly used for the drying of petroleum cracking gas, olefins, refineries and oilfield gas. It is an industrial desiccant for chemical industry, medicine, hollow glass, etc.

Chemical formula: 2/3K2O.1/3Na22O.AI2O3.2SiO 2.9/2H 2

Main uses: 1. Drying of liquids (e.g. ethanol)

2. Air drying in hollow glass

3. Drying of mixed gases of nitrogen and hydrogen

4. Drying of Refrigerants

Type 4A zeolite:

Mainly used for natural gas and various chemical gases and liquids, refrigerants, pharmaceuticals, electronic materials and the drying of volatile substances, argon purification, methane, ethane and propane separation.

Chemical formula: Na2O Al2O3 2SiO 2 9/2H 2

Main applications: 1. Deep drying of gases and liquids such as air, natural gas, hydrocarbon fines, refrigerants, etc.

2. Production and purification of argon;

3. Static drying of electronic components and moisture-prone deteriorating substances;

4. Dehydrating agents in paints, polyesters, dyes and coatings.

5A zeolite:

Chemical formula: 3/4CaO.1/4Na2O.Al2O3.2SiO 2.9/2H 2

Main uses: 1. Natural gas drying, desulfurization, carbon dioxide removal;

2. Separation of nitrogen and oxygen and separation of nitrogen and hydrogen to produce oxygen, nitrogen and hydrogen.

3. Dewaxing of petroleum and separation of normal hydrocarbons from branch hydrocarbons and cyclic hydrocarbons.

The large specific surface area and polar adsorption of 5A zeolite achieve deep adsorption of water and residual ammonia. The decomposed mixture of nitrogen and hydrogen enters the dryer to remove residual moisture and other impurities. The purification unit adopts a double adsorption tower process, one adsorbs dry ammonia decomposition gas, the other desorbs water and residual ammonia in the heating state (generally 300-350 C), so as to achieve the purpose of regeneration.

13XAPG molecular sieve:

It is mainly used for the purification of raw gas in large and medium-sized air separation units.

Molecular sieves for hollow glass:

It can absorb water and residual organic matter in hollow glass at the same time, so that hollow glass can remain transparent even at very low temperature, and reduce the strong pressure difference between inside and outside of hollow glass due to seasonal and diurnal temperature variation. It can thoroughly solve the distortion and breakage problem caused by the expansion or contraction of ordinary hollow glass caused by ordinary hollow glass desiccant, and fully prolong the hollow glass. The service life of glass.

Molecular sieve activation powder series:

It is a molecular sieve that synthesizes the dehydrated molecular sieve. It has a certain dispersion and fast adsorption speed. It is mainly used as additives for coatings, paints, resins and related adhesives.